The Science of Sleep

Sheryl Shook
The Science of Sleep
Sheryl Shook
 To my dear students.
You continue to inspire me.

Unless otherwise noted, this work is licensed by Sheryl Shook

under Creative Commons Attribution License v4.0.

Complete permissions can be found on pages 117–26.

 Contents
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Guide to the Textbook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Yawning and an Introduction to Sleep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1 Sleep Wellness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Determining Sleep Need . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Napping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Sleep Wellness Guidelines: Daytime, Before Bed, In Bed . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Sleep Wellness: Beyond the Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Cognitive Behavioral Therapy for Insomnia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Additional Support during Pregnancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Family Sleep and Bed Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Social Justice and Sleep Wellness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2 The Sleeping Brain: Neuroanatomy, Polysomnography, and Actigraphy . . . . . 29

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Brain Anatomy and Physiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Polysomnogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Sleep Stages: REM Sleep and Non-REM Sleep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Sleep Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Actigraphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

3 Circadian Rhythm .................................................... 49

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Circadian Rhythm and Sleep Pressure Don’t Always Agree . . . . . . . . . . . . . . . . . . . . . . . . 49
How Many Hours Are in a Day? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Sunlight, Larks, and Night Owls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Derailing the Circadian Rhythm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Polyphasic versus Biphasic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

4 Animals ............................................................. 61
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Insects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Reptiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Birds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Mammals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Hibernators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5 Dreams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Emotional Healing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Memory and Learning.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Problem Solving and Creativity.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Emotional Intelligence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
How and Where Dreams Are Created.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Interpretation of Dreams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Dreams in Different Cultures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Lucid Dreaming.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Conducting a Dream Group.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

6 Sleep Disorders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Insomnia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Snoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Obstructive Sleep Apnea.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Central Sleep Apnea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Sudden Infant Death Syndrome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Restless Legs Syndrome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Periodic Limb Movements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Sleep Leg Cramps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Bruxism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Sleep Paralysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
REM Sleep Behavior Disorder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Sleep-­Related Eating Disorder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Sleepwalking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Bad Dreams, Nightmares, and Night Terrors.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Bedwetting.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Jet Lag.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Short Sleeper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Delayed or Advanced Sleep-­Wake Phase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Narcolepsy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Clinical Sleep Study.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

7 Politics, Sleep, and You. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Economics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Antiracism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Business. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
High Schools and Colleges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Health-­Care Providers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Your Next Steps.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Image Credits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

 Acknowledgments

This book and my deep dive into open educational requests, year after year, that I create it. Every
resources (OER) are thanks to Sunny Pai. I fondly semester I teach my class on the science of sleep,
recall the moment by Lama Library when she opened I feel deeply blessed to meet all these courageous,
my eyes to the social justice impact of OER and the talented, compassionate, humorous students, who
myriad benefits of zero-cost textbooks. From that are eager to explore every imaginable dimension of
time on, her heroic efforts have been instrumental sleep and even willing to laugh at my jokes!
to this project and my growth as an OER advocate. Thank you to my mom and dad, Coy and Sherry
I am tremendously grateful for Jason Ford who, Shook, for giving me so much unconditional love
with Sunny Pai’s collaboration, took on the quest to and acceptance. The opportunities they created for
find over one hundred open-access images to bring me were such treasures and an enormous part of
my manuscript to life. In addition to lending his who I am today.
artistic vision, Jason also tuned in to my aesthetic for Through her graceful combination of strength,
the book, and that is testimony to his brilliance and humor, and wisdom, my daughter Mary provided
intuition. Not only could I have never found all those me with insights and meaningful conversation,
images; the book would surely be another year in especially around social justice and antiracism, that
the making without Jason’s genius. Nicholas Wong impacted this book and beyond. My son, Doug Jr.,
also deserves some of the appreciation, as he found brought the best stories, laughs, and music exactly
several images during the early phase of this project. when I needed them. Time after time, my daughter
I am thankful to the artists who created all those Angie gave me caring and comfort in her home,
meaningful images and made the choice to share especially during those long hours I spent writ-
with no paywall so my readers will have the plea- ing during “breaks” at the semester’s end. I am
sure of seeing their work. Special thanks to Stéphane enormously grateful for all three of my children for
Granzotto for his generosity in giving us permission providing the inspiration, good times, and hope I
to use his whale photo that Jason, Sunny, and I were needed to get this book written.
in awe of when we saw it in National Geographic. My muse, surfer boy, and man of my dreams,
My profound thanks to Anya Dimitrijevic, Somer Doug Fetterly, deserves my warmest appreciation
Rickards, ‘Iwalani Clayton, Malia Hasegawa, Tiare for being by my side while writing and surfing and
Sabellano-Tsutsui, Mary Shook-Starsinic, Hikialani dancing and nurturing me so I could write and write
Guzman, and Joyce Tokuda for creating imagina- and write. I also send admiration to Doug for teach-
tive artwork that is nowhere else to be found. I am ing me how to show up in Washington, DC, and
inspired by their generosity, providing these images lobby Congress, and for the many ways he models
with open-access attribution licenses so others will civic engagement.
be able to benefit from their creations. Additional I send heartfelt gratitude to my dear grandchil-
thanks to ‘Iwalani Clayton for verifying ‘Ōlelo dren, who provided me with the spark and vitality
Hawai‘i (Language of Hawai‘i) throughout the book. to write this book by bringing me joy, love, and
One of the many reasons I dedicated this book a sense of belonging that are beyond my wildest
to my students is because of their wholehearted dreams.
 Guide to the Textbook

1. Student Learning Objectives 2. Ready to Move

2. Ready to Move On? On?
3. Retrieval Practice
In Native American culture,
4. ‘Ōlelo Hawai‘i (Language of Hawai‘i)
power animals are spirit
5. Your Next Actions for Justice
guides that teach, lead, and protect. Many
tribes have a group of power animals
called “tribe totems” that are emblems
1. Student Learning of their people and lineage. Particularly in
Objectives Cherokee culture, the wolf is an important
tribe totem, and it has been regarded by
This is an Adinkra symbol that represents knowl- many Native American tribes as a teacher
edge and the potential to learn anything that you or pathfinder. The wolf often symbolizes
do not yet know. It is called “Nea Onnim,” which intelligence, guidance, intuition, and
means “the one who doesn’t know” in Akan. It perseverance.
refers to the proverb that states, “The one who This narrative and image were created
doesn’t know can know through learning.” Adin- by Anya Dimitrijevic (of Cherokee ances-
kra symbols appear often in parts of Ghana as art, try). The wolf was chosen as a reminder to
jewelry, and even bumper stickers! The philoso- take time and reflect on what you learned.
phies found throughout West Africa are infinitely When you see the wolf, follow the instruc-
profound and deserve just as much attention as tions to engage with the content and
any other world-renowned philosophies. reinforce the concepts before moving on
This narrative and image were created by Mary to the next section.
Shook-Starsinic (an Africana studies graduate
from San Francisco State University), and the pic-
ture accompanies each chapter’s student learning
objectives. The Adinkra symbol at the beginning 3. Retrieval Practice
of each chapter is a reminder to consider some of The image of the dog retrieving
the things you will learn and be able to do after the toy is to let you know it is time
reading the chapter. for some retrieval practice. You
will find detailed directions for an
activity that will reinforce learn-
ing. Neuroscience research suggests that retrieval
practices are one of the most effective ways to
learn content. The photo of the dog is from Brixiv
on Pexels.
x • Guide to the Textbook

4. ‘Ōlelo Hawai‘i 5. Your Next

(Language of Actions for
Hawai‘i) Justice
The honu (Hawaiian green Maat is the Egyp-
sea turtle) holds a sacred place among tian goddess of jus-
Hawaiians as an ‘aumakua (family or tice, truth, harmony, and balance. She is
personal god). The honu symbol repre- seen comparing the weight of a feather to
sents many things in Polynesian culture, the heart of a person’s soul to determine
including longevity, safety, mana (spiri- if they had lived in an ethically balanced
tual energy), and protective wisdom (that manner. The heart is the symbol for the
comes with age). It is a bearer of good luck, person’s conscience.
peace, health, rest, endurance, and per- Somer Rickards (eighth-grade teacher
severance as well as a navigator. The honu and artist) created this image. Please
is one of the last remaining indigenous consider the suggestions that accom-
reptiles living on the Hawaiian Islands. pany this image. They provide ideas for
The kākau or kākau kaha is a form of the next steps you can take toward social
tattooing in Hawai‘i. Tattoos were con- justice as it relates to sleep wellness.
sidered protective talismans or personal
representations in Polynesian culture. In
this image, the two outer vertical rows
of waves represent ola (life, continu-
ity, change) and ‘ao‘ao mau o ka honua
(afterlife). The vertical marks located
in the center row are of the interlocking
manō (shark) teeth representing protec-
tion, strength, guidance, and adaptability.
The honu and kākau images are on
a backdrop of the Hawaiian kapa (the
beaten thing) or tapa cloth, like the kīhei
(cape), symbolizing home and protection.
In bringing all three together, the image
here is one of peace, rest, and protection.
Mālama pono.
This narrative and image were created
by ‘Iwalani Clayton (of Native Hawaiian
ancestry), who also verified the use of
Hawaiian words throughout the book.
This image is incorporated to emphasize
some of the ‘Ōlelo Hawai‘i that appears in
each chapter.
 Yawning and an Introduction to Sleep

Yawn. There, I said it. And I even provided an image • animal sleep and behaviors like sleeping
(figure I.1). Now you will likely be yawning for the while swimming or flying
next few minutes, and if anyone sees you reading • disorders such as teeth grinding,
my book, they will say, “I’m not going to pick up sleepwalking, and sleep paralysis
that book! Boring, eh?” But hopefully, you will find
sleep science irresistible enough that you will join Yes, these are compelling topics, and I cover
me in engaging people in conversations about sleep, them all and much more. But my passion? It comes
its truths as well as its myths—such as boredom from my fierce commitment to helping people
being the cause of yawning. determine how they can do two things:
Why am I so passionate about sleep—talking
about it, teaching college lecture and lab 1. Improve their sleep and enjoy the associated
courses about it, giving workshops around the health benefits
world about it? It goes way beyond how fascinat- 2. Find their place in creating a revolution
ing some things about sleep are, such as so more people will understand sleep’s
importance and have the opportunity to get
• the meaning of dreams and nightmares enough of it
(figure I.2)

Figure I.1 Yawning

 2 • Yawning and an Introduction to Sleep

to create healthy habits such as quitting smok-

ing, improving food choices, and getting exercise
and the case for prioritizing sleep becomes even
clearer.
While you sleep, there are changes in your brain,
cardiovascular system, and metabolism as well as
your body’s healing pathways. Most of us have
noticed the slow thinking and crankiness associ-
ated with poor sleep, but did you know your brain
Figure I.2 Dreams is taking out the garbage while you sleep? During
sleep, a set of structures that comprise the glym-
Sleep quality is one of the strongest pre- phatic system flush out toxins and waste associated
dictors of how long you will live and how good with an array of neurologic problems.
you will feel, mentally and physically. In most To keep your heart and blood vessels healthy,
circumstances, sleep quality can be a stronger your body will also need sleep. It is essential to
predictor of longevity than diet, blood pressure, blood pressure regulation. Sleep reduces the risk
cigarette use, or genetics (figure I.3). Healthy of cardiovascular disease and stroke. Many peo-
sleep changes which of your genes are expressed. ple, hoping to avoid a myocardial infarction (heart
Combine this with the fact that good sleep causes attack), try to manage their health with foods,
changes in brain physiology that make it easier and that is a good idea, but they would be wise to

Figure I.3 105 year old woman

 Yawning and an Introduction to Sleep • 3

Figure I.4 Some of the effects of sleep deprivation

also address their sleep as if their lives depend on We know that sleep provides a spark for crea-
it—because they might. tivity and problem solving as well as laying down
Sleep is crucial for maintaining a balanced the physiological changes for learning and memory.
metabolism and managing appetite, blood sugar, While there are numerous stories such as how the
and diabetes. This is related to poor sleep’s effect melody of “Yesterday” came to Paul McCartney in
on hormones, which can make you feel as though a dream, that type of inspiration translates to most
you are starving even though you have eaten plenty. of us as solutions to the previous day’s problem that
Insulin sensitivity (related to diabetes) also takes a become apparent after “sleeping on it” (figure I.5).
drastic turn for the worse if someone is not getting This common (and wise) expression alone, and its
enough sleep. existence across cultures, points to the now scien-
Inflammation and oxidation, recognized more tifically based fact that sleeping and dreaming help
commonly in relation to injuries and healing, are us create solutions and solve problems.
also underlying mechanisms in many diseases, There is a tragic catch. Who has the luxury of
including several neurologic disorders. We will see putting into practice the recommendations of the
that sleep is essential for reducing oxidation and numerous healthy sleep articles going around? Who
inflammation and promoting healing, reducing of those in society can carve out eight hours each
pain, and lowering risk for neurologic disorders night in a quiet, dark, comfortable, temperature-
(figure I.4). controlled room? It is painful to see the studies
 4 • Yawning and an Introduction to Sleep

Figure I.5 Sleeping on it

showing correlations between poor sleep and race, simple.”* Let’s get together, put the information
sexual orientation, economic group, and educa- from this book in motion, and create a sleep well-
tion level. ness revolution. I invite you to work with me to
The majority of those who get good sleep are achieve that dream.
already at an advantage based on race, sexual But what about yawns? Oh, there you go again.
orientation, economics, and education. If the Yawning at my book. The good news is, if you
research continues to pile up showing the con- catch yawns, that it is an indication you are
nection between good sleep and being smarter, empathic. Empathy is the ability to share and
faster, stronger, and more successful, we must understand another person’s feelings, so it is a
take responsibility and address the sleep wellness treasured quality—one that is correlated with the
gap. There is an essential element of social justice, contagiousness of yawns. To back this claim up
antiracism, and inclusion work in sleep science, so with the behavioral evidence, brain imaging stud-
in each chapter, we will discuss this and provide ies show that the areas of the brain activated during
ideas for how you can have an impact in your com- yawning are associated with understanding oth-
munity and beyond. I have also dedicated a chap- ers’ feelings. Yawning is typically not contagious
ter to equity, politics, and sleep. As Zoë Heller has in children under five years old, as they are still
asserted in her New Yorker article, “The fact that building their capacity for empathy with each year.
some of the leading indicators for poor sleep and Yawning’s contagiousness may be valuable as a
sleep loss are low household income, shift work, signal among animals to coordinate behavior—for
food insecurity, and being African-American or example, as a way to say, “It is time for all of us to
Hispanic suggests that the quest for rest is not so go to sleep.”

* Zoë Heller, “Why We Sleep, and Why We Often Can’t,” New Yorker, December 3, 2018, https://www.newyorker.com/magazine/
2018/12/10/why-we-sleep-and-why-we-often-cant.
 Yawning and an Introduction to Sleep • 5

it is when someone interrupts your yawn? Why do

we feel the need to complete it? It turns out the full
stretching of the jaw brings blood flow to several
muscles too, thus increasing the volume of blood
that is cooled due to the radiator effect of the air
movement over the nearby mucous membranes.
The research studies that led to this conclu-
sion involved having participants place warm or
cool packs to the head while watching films of
people yawning. Scientists observed that par-
ticipants yawned significantly less with the cool
Figure I.6 Yawning is not just for humans pack on their heads. There are also times during
the twenty-four-hour day that people yawn more
Contagious yawning could also help a group often, and there are explanations that can be related
react quickly to a sudden increase in tempera- to brain cooling. Right before bed, body tempera-
ture. Disproving earlier theories that yawning is ture is usually at its highest, which could trigger
a response to low oxygen, the current research yawning. Upon awakening, body temperature is
suggests yawning’s purpose is to cool the brain. quite low but increasing at its fastest rate, prompt-
So when one animal yawns, others nearby might ing a reflex for cooling—morning yawns. However,
begin yawning too because if one of them is getting there are other times during the day when the body
warm, the rest will soon be in need of the brain- increases to or even sustains a higher temperature,
cooling benefit of a yawn too (figure I.6). so there are clearly complicating factors involved
But how does yawning accomplish this cooldown in understanding the complete picture. Months
effect? As we suck in air, it moves across the moist or decades from now, another scientist—perhaps
mucous membranes of the nasal and oral passage- you—will come along and turn this theory upside-
ways, cooling the blood in the numerous tiny blood down with fresh insight.
vessels just below the surface. The effect of this This is one of the satisfying aspects of studying
is that the blood flow in the head is cooled, and sleep science right now: The frontiers of knowledge
scientists speculate that coolness is transferred to are expanding. Today’s genius postulate may be
the brain. Have you ever noticed how unsatisfying tomorrow’s balderdash. Join me in the wilderness!
 1
Sleep Wellness

Student Learning by Daniel Buysse in 2014.* (In the article, scroll

down to figure S1 for the questionnaire.) Part of
Objectives the motivation in the development of SATED was
After you read this chapter, you will be able to to help researchers and clinicians move away from
• determine sleep need a sleep disorder–centric model of thinking and
• discuss the benefits of napping provide a way to assess and promote sleep health.
• describe the habits that fix problematic This is because if we view wellness as an absence of
sleep and support healthy sleep disease, we are missing opportunities to increase
• explain the concept of a sleep diary health in our communities. By defining, and thus
• guide, in the role of a layperson, someone being able to evaluate, a person’s sleep health,
through cognitive behavioral therapy for we have a better opportunity to prevent disease,
insomnia maximize wellness, and have an impact on entire
• address pregnancy-related sleep communities. Concerns can be addressed, and edu-
challenges cational interventions taken, to prevent the tragic
• describe the values and safety of the family effects of sleep debt. If, in addition to the traditional
bed programs focused on disease treatment, political
and health-care policies support health practi-
tioners in assessing the well-being of individuals
and communities to determine educational targets,
Introduction we could take a significant leap toward increasing
The previous chapter likely convinced you of the vitality and preventing disease.
importance of sleep, but how do you get that sleep? In his article, Buysse stresses the difficulty
Identifying and establishing the behavioral changes of conducting meaningful research and making
necessary to improve sleep can be elusive, so I will health policy changes without a clear under-
guide you through a simple methodical approach standing of sleep health, pointing to the lack of
for success. Rest assured, most people start sleep- a clear definition of this term in the scientific
ing better after making a few small adjustments to literature and the field of sleep medicine. The
their routines or environment. This chapter will SATED questionnaire is part of his attempt to
help you create habits for boosting your sleep. provide a better understanding of what consti-
To begin, identify your current level of sleep tutes healthy sleep. He considers sleep health to
wellness with the SATED questionnaire, published have five dimensions:

* Daniel J. Buysse, “Sleep Health: Can We Define It? Does It Matter?,” Sleep 37, no. 1 (January 2014): 9–17, https://doi.org/10
.5665/sleep.3298.
 8 • Sleep Wellness: Determining Sleep Need

• Satisfaction with sleep 4. When you go to bed at night, do you fall

• Alertness during waking hours asleep “when your head hits the pillow”?
• Timing of sleep 5. Do you doze off during a boring meeting,
• Efficiency of sleep conversation, or TV show? (figure 1.1).
• Duration of sleep
Answers to these simple questions reveal if
you’re getting enough good-quality sleep. If it is
Determining Sleep Need adequate, your answer to questions 2 and 3 would
Before diving into detail about how to get good be yes but no to questions 1, 4, and 5. Question 4
sleep, let’s agree on how much is enough. For is the only one that may not be obvious: some of
most adults, it is around eight hours, and for many you likely believe it is a healthy sign to fall asleep
adults, a little more than eight. Even if you get that immediately upon getting in bed, but that in fact is
much, you may wonder how to verify if it is of good a sign of an extreme lack of quality sleep. It should
quality. That is easier to ascertain than you might take about fifteen minutes to fall asleep if a person
imagine. is getting enough good sleep each night. Similarly,
Here are questions to ask to determine if you regarding question 5, a person might assume they
are getting adequate sleep: are getting ample sleep and that it is normal to doze
off if they had an exhausting day and are watching
1. After being up for two hours in the morning, a TV show in the early evening. However, these
if you were to go back to bed, would you be situations are actually unmasking sleep debt and
able to fall asleep? are a signal that more sleep is needed.
2. If you did not set your alarm, would you wake What about sleeping too much? This concern can
up automatically at the desired time, feeling often be traced to a misinterpretation of research
refreshed? showing a correlation between nine or more hours
3. Without caffeine or nicotine during the day, of sleep a night and a shorter life-span. However,
would you easily stay awake and alert? there is no evidence that more good-quality sleep
is the cause. Rather, having a disorder such as
obstructive sleep apnea (OSA) can cause a per-
son to stay in bed nine or more hours a night (see
chapter 6). In this case, they will report they are
“sleeping” nine or more hours, but unbeknownst
to them, they are not actually getting quality sleep
during those nine hours, and that is why they end
up staying in bed so long. After the eighth hour in
bed, their body is still trying to get sleep because
they may have been awakened, without knowing it,
hundreds of times during the night due to breath-
ing issues. So untreated OSA is what increases
the risk of an earlier death, not excessive sleep.
Someone without OSA who spends nine hours each
night going through healthy sleep cycles and feels
refreshed throughout the day would not have an
increased risk of an earlier death. Please use this
content to deliberate with a classmate about cor-
Figure 1.1 Nap relation versus causation.
 Sleep Wellness: Determining Sleep Need • 9

Ready to Move On?

Before moving on, be sure you are clear about the difference between correlation
and causation.

Correlation: a connection between things

Causation: one thing plays a part in making another thing happen

Just because there is a correlation between things, it does not mean one thing causes the other.
It is important when you are reading about science that you are able to tease out the difference
between correlation and causation. If someone is trying to convince you of something, they
may make it difficult to tell the difference.
Engage a classmate in a conversation and respond to each of the three prompts below. You may
draw on simple things from your own life, something from your imagination, or even science:

1. Describe a situation where there is a correlation between two things. For example, if I surf in
the morning, I am happier the rest of the day. There is a connection between my happiness
and surfing.
2. Describe a situation where one thing obviously causes another. For example, while
riding a wave, if I stand too far forward on my surfboard, I will pearl (a.k.a., nosedive—as
in, “Hey sistah, you looked like you were diving for pearls!”). Standing near the front of
my surfboard plays a part in making the nose of my surfboard dive underwater. That is
causation.
3. Describe a situation where there is a correlation between two things but there is obviously
not causation. For example, on the days I surf, I gain a little weight. Does this mean surfing
causes me to gain weight? That does not make sense, does it? So if I wrote an article telling
people to avoid surfing if they were trying to lose weight, I hope you would read it critically
and try to find out other explanations for the correlation. Perhaps after I go surfing, I
always go eat double loco moco, a popular dish in Hawai‘i that includes two scoops of rice,
two fried eggs, a hamburger patty, and gravy. What do you think?

One factor that must be included in discus- individuals wear an actigraphy device or poly-
sions of the ideal amount of sleep is sleep oppor- somnography equipment, the results may show
tunity. Going to bed at 11:00 p.m. and arising at that during those eight hours, they sleep less than
7:00 a.m. does not mean a person has slept eight four hours or, under the best of circumstances,
hours. This means the person was providing them- seven and a half hours (see chapter 2 for a dis-
selves a sleep opportunity of eight hours (the time cussion of actigraphy and polysomnography). You
they spent in bed) with the time of actual sleep still may be wondering why, under the best of circum-
to be determined. This is often an area of confu- stances, eight hours of sleep would not be obtained
sion in interpreting population studies of sleep. after eight hours in bed. This is because it is normal
In questionnaires, people likely report that they to take fifteen minutes to fall asleep (as mentioned
sleep eight hours if they are in bed from 11:00 p.m. at the start of this chapter) and to have a few tiny
to 7:00 a.m. However, if you have those same awakenings during the night (most of which we are
 10 • Sleep Wellness: Determining Sleep Need

Figure 1.2 Kalahari ǂKhomani San Bushman

usually unaware). If we recommend a person get results made for profitable press. But what actu-
eight hours of sleep, we are referring to actual sleep, ally happened?
which requires being in bed for eight hours plus the The researchers studied people from three tribes:
time it takes to fall asleep and any additional time the Hadza (Tanzania), Tsimané (Bolivia), and
for awakenings during the night. This means most San (Kalahari; figure 1.2). The idea was that since
people need to give themselves a little over eight these are preindustrial tribes, the way they sleep
hours in bed each night. is how we city dwellers should too. The members
One fascinating study that received consid- of the tribes wore actigraphy devices that showed
erable press—press that misrepresented the an average of 6.75 hours of sleep per night for the
scientists’ conclusions—was regarding hunter- duration of the study. A layperson’s interpretation
gatherer tribes and their sleeping less than seven of this could be that the tribal member was in bed
hours a night. Understanding this study will help for 6.75 hours; consequently, that layperson may
you comprehend the difference between sleep effi- believe they achieve optimal sleep health if they go
ciency and sleep opportunity as well as encourage to bed at 1:15 a.m. and get up at 8:00 a.m. However,
you to think critically when hearing news stories. for a sleep efficiency of 85 percent (the low end of
Consider, for example, how a headline in popular the healthy range), a person would have to be in bed
media that tells people “You do not really need 7.9 hours to get 6.75 hours of sleep (see chapter 2
8 hours of sleep” will sell magazines. Even though for a discussion of sleep efficiency).
that was likely not the intention of the scientists But wait—how long does it take the person to fall
who conducted the study, this distortion of the asleep? Under ideal circumstances, a person falls
 Sleep Wellness: Napping • 11

asleep in 15 minutes (0.25 hour), so add 0.25 hours a person looking for the ideal amount of sleep to
to the 7.9 hours to get 8.15 hours (8 hours and get each night for the sake of health optimization
9 minutes). This means that if a person has both and longevity.
healthy sleep efficiency and sleep latency (time to
get to sleep), they need to be in bed 8.15 hours
Napping
to get 6.75 hours of sleep. It is doubtful that most
people interpreted the popular-press headlines Napping makes us stronger, faster, smarter, and
(boasting we need less than 7 hours of sleep) of this happier, and it helps us sleep better at night. From
research as guidance to be in bed for over 8 hours; the prophet Muhammad, who recommended
rather, many people probably ended up getting a midday nap (qailulah), to the Mediterranean
less than 6 hours a night, thinking they were on concept of a siesta, napping has spanned cultures
track because they allowed themselves 6.75 hours and the ages (figure 1.3). The word siesta derives
of time in bed as their new healthy goal. The actual from Latin: hora sexta, meaning “sixth hour.”
study supports this as well: the tribespeople were Here is why that makes sense: the day begins at
giving themselves between 7 and 8.5 hours of sleep dawn, around six in the morning; consequently
opportunity a night.* the sixth hour would be around noon—siesta time!
As a science student, the lesson for you in this is Only recently have modern North Americans, on
to think critically when reading news stories, ask a larger scale, embraced the practice of napping,
yourself if the reporter has an agenda, and most thanks to extensive research showing the mental
importantly, look for the source of the data and find and physical health benefits of a brief amount of
the original article. See if that article is in a peer- sleep shortly after midday. This is the time we have
reviewed scientific journal, and read the article a genetically programmed dip in alertness—the
itself critically as well. signal to nap—that is a function of our human cir-
In his book Why We Sleep, Matthew Walker, PhD, cadian rhythm, regardless of ancestry.
adds further fuel to the argument that these tabloid If we take the sleep wellness advice, adjust our
headlines are harmful and misguided. He points routines, and start getting eight hours of sleep a
out that the life expectancy for people in these night, it can feel disappointing to still feel drowsy
tribes is fifty-eight years, a number very close to in the afternoon. However, it is time to create a
the projected sixty-year life-span of an adult in an new habit of celebrating that afternoon slump as
industrialized country who gets 6.75 hours of sleep a healthy response in the body, even after sleeping
a night. He also refers to animal studies indicating well the night before. Drowsiness at this time is a
that the cause of death in sleep-deprived animals is valuable reminder to take a ten- to twenty-minute
the same lethal intestinal infection that is the cause nap. Remember to set an alarm to train the body to
of death for many of the tribespeople of the study. limit the nap’s duration, and with practice, you will
He reasons that the tribespeople may be sleep- wake up just before the alarm sounds. The groggy
ing 6.75 hours, but they might live longer if they feeling upon awakening from a nap might be a
were to sleep more. He then postulates that the deterrent for even an ardent napper. This is sleep
reason they sleep less is due to a lack of sufficient inertia, and with a more regular napping routine, it
calories; they border on starvation for a significant will be easily managed. Knowing you will have that
part of each year. There are physiological cascades sensation and that it will pass, usually within ten
that shorten sleep if the body needs to spend more minutes, will make it easier to settle down for the
time acquiring food. This is clearly not the goal for nap. Some people who enjoy caffeine, and have

* Gandhi Yetish et al., “Natural Sleep and Its Seasonal Variations in Three Pre-industrial Societies,” Current Biology 25, no. 21
(November 2015): 2862–68, https://doi.org/10.1016/j.cub.2015.09.046.
 12 • Sleep Wellness: Napping

this with the amplification of creativity after nap-

ping and we see why students at colleges around
the world are finding ways to get a nap on campus
(see chapter 7).
When trying to avoid a cold or the flu, people are
willing to spend a lot of money on immune support
supplements and vitamins, but one of the stron-
gest ways to provide powerful immune support is
free (figure 1.5). After a night of poor sleep, anti-
viral molecules such as interleukin-6 drop and
reduce immune system power. However, a nap
can bring those levels back to normal. Researchers
have also found increased levels of norepineph-
rine, the “fight or flight” molecule, after reduced
nighttime sleep. Sustained high levels of norepi-
nephrine, associated with the stress response,
have harmful effects on blood glucose balance
and cardiovascular health. Napping brought the
Figure 1.3 Siesta norepinephrine levels back within their normal
range. Similarly, since one in three adults in the
tested to be sure it is not affecting their nighttime US have high blood pressure, it is welcome news
sleep, might want to have some right before their
nap or immediately upon waking to help manage
sleep inertia, but this isn’t always necessary. The
quality of clear and relaxed energy that takes you
well into the evening, as opposed to the energy
crash from not napping and using caffeine or nico-
tine in place of a nap, is usually enough to motivate
someone to maintain a napping habit. Since the
body has not been on a roller coaster of drowsi-
ness during the day, thanks to the missed nap and
possibly the use of stimulants, it approaches bed-
time in a more even and restful state, and a better
night’s sleep should follow.
Students hoping to optimize their study efforts
would be wise to close the book and take a short nap
(figure 1.4). Naps increase memory performance,
and scientists have documented particular types
of brain activity that are associated with enhanced
learning during naps, including sleep spindles
(see chapter 2). When working on a homework
set, the skill of restructuring—viewing a problem
from various perspectives and creating a novel
vision—is an ingredient for success that can be
obtained via a brief afternoon snooze. Combine Figure 1.4 Napping boosts learning
 Sleep Wellness: Sleep Wellness Guidelines: Daytime, Before Bed, In Bed • 13

communities began deciding to keep the businesses

open rather than shut down for a siesta as they
always had. Around that time, Harvard researchers
examined over twenty thousand Greek adults with
no cardiovascular disease. When they followed up
after several years, the individuals who had given
up napping had seen a 37 percent increase in their
risk of dying from heart disease. For working men,
it was an over 60 percent increase. A more hope-
ful way to view this is that the risk of dying was
reduced by these significant amounts for those who
continued napping.

Sleep Wellness Guidelines: Daytime,

Before Bed, In Bed
Refer to the Sleep Wellness Guide below and take
inventory, noting areas that you need to address.
Prioritize each of those problem areas based on
the significance of its impact on sleep, the feasibility
of making change, and the value its implementa-
tion would have for the individual. This increases
success by helping people see the flexibility of the
approach and how they can control the process.
Figure 1.5 Skip the side effects and choose napping
• Significance: If a person is having caffeine
late in the day and it is keeping them
that a daily nap can bring that down as effectively awake, the caffeine is having a significant
as medications and other lifestyle changes. impact on their sleep. Therefore, avoiding
Athletes have been converting en masse to nap- caffeine—or having it earlier—may solve
ping based on research showing the benefits it has the problem without the need to address less
for athletic performance as well as increased motor significant areas. Putting the effort toward
learning, even after a nap as short as ten minutes changing behavior in less significant areas
(figure 1.6). Athletes, such as sprinter Usain Bolt, while continuing something significantly
have shared stories of napping earlier in the day disruptive, such as caffeine intake, might
before a record-breaking performance. Adam not result in any improvement. In addition
Silver, National Basketball Association commis- to being ineffective, it is frustrating because
sioner, cautions those who want to contact athletes you feel like you are putting in effort and not
during siesta time, “Everyone in the league office getting results.
knows not to call players at 3 p.m. It’s the player • Feasibility: All items on the Sleep Wellness
nap.” Guide are not feasible for everyone. If
If you are still not convinced of the importance someone is a shift worker or caring for a
of napping, consider the distressing consequences family member, it may not be possible to
when many healthy Greeks gave up napping. This get to bed at the same time every night.
occurred when business owners in many Greek Determine a way to address this item that
 14 • Sleep Wellness: Sleep Wellness Guidelines: Daytime, Before Bed, In Bed

Figure 1.6 Power naps for power athletes

recognizes the reality of the situation. pleasure. He agreed to instead switch from
For example, could you go to bed and get a large to a small bowl to reduce the serving
up at the same time four days a week and size. I asked him to choose an artistically
maintain a different sleep schedule the pleasing little bowl, hoping to tap into an
other three days. additional pathway to the reward center
• Value: Do you really enjoy that bowl of ice of his brain. We discussed the concern of
cream when watching a movie right before heightened sugar levels right before bed
bed? Sleep wellness is not about giving and decided to offset this by, in addition to
up life’s pleasures. One sleepless client I reducing the portion, rolling up a piece of
worked with told me he had addressed all sliced turkey and eating it while he scooped
the items in his sleep wellness inventory but his ice cream into the bowl. This would help
was still not getting quality sleep. We went balance out the sugar-to-protein ratio of
over his daytime and evening routines, and his late-night snack. Now, he still gets to sit
I found out he truly treasured his ice cream, and enjoy his bowl of ice cream, but thanks
a generous serving of it, shortly before bed. to those adjustments, his sleep is now
I did not want him to deprive himself of this satisfactory.
 Sleep Wellness: Sleep Wellness Guidelines: Daytime, Before Bed, In Bed • 15

Sleep Wellness Guide

During the Day
• Get a little sunlight on your face first thing in the • Take a ten-to-twenty-minute nap around
morning to set your circadian rhythm. 2:00 p.m.—our bodies are meant to sleep two
• Exercise, taking at least a brisk twenty-minute times a day.
walk each day. • If you are awakening to urinate at night, then
• After noon, avoid caffeine, guarana, and other during the day, elevate your legs often and also
stimulants (e.g., chocolate, black or green tea, do heel/toe raises to absorb fluid (accumulated
coffee, soda, energy drinks). in legs) that would be processed by kidneys at
• Avoid alcohol within five hours of night.
bedtime—alcohol disrupts brain activity critical • Ask your doctor about the effects any
for healthy sleep. medications you take might have on
• Quit cigarettes/nicotine because nicotine at any sleep—healthy sleep can be disrupted by some
time of day disrupts sleep; get support from a prescription and over-the-counter medications
local smoking cessation program. (even some “sleep” medications).
• If you are not quitting smoking, avoid cigarettes/ • Keep a sleep diary*—many people are surprised
nicotine within five hours of bedtime. by what they find out at the end of a week.

Before Bed
• Practice a ritual (e.g., take a bath, read a relaxing • If nighttime urination is a problem, minimize
book, meditate, sing). See the UCLA Mindful water intake—consider no fluids within ninety
Awareness Research Center, marc.ucla.edu, for minutes of bedtime. Try no herbal tea at least
guided meditations. five hours before bed to determine if that is a
• Eat a light snack with minimal sugar (e.g., milk factor. Urinate immediately before going to bed.
and cereal, fruit and yogurt, nuts and crackers). • Start a relaxation practice before bed—begin
• Avoid light from lamps, computers, televisions, with three minutes of quieting your mind, sitting
and cell phones within one hour of bedtime. still.
This light disrupts melatonin production and • Practice slow breathing. Gently push out the
thus circadian rhythm. Alternatively, use blue belly as you inhale, hold, then slowly exhale,
light–filter glasses or apps. relaxing the belly back to a neutral position.

While in Bed
• Keep the room completely dark—no streetlights • Make the room quiet or use white noise
or night-lights unless very dim or orange. (recordings of the ocean, a fan, rain, etc.) to
• If you do not fall asleep within what feels mask disruptive sounds.
like twenty minutes, get out of bed and do • Position your clock so it is not visible during the
something relaxing (e.g., read a calming book, night, and do not check the time if you wake up.
listen to an audiobook). • If you need to get up to urinate, use dim and
• Keep the room cool, around 65–68 degrees orange lighting just bright enough for safety.
Fahrenheit (18–20 degrees Celsius). • Go to bed and get up at the same time every day,
• Use the bed only for sex, sleep, and gentle even on weekends.
reading / audio files (no emailing, television, • Sleep approximately eight hours.
working, etc.).

Before making any changes to your routine, consult your physician.

* Shook, Sheryl, “Sleep Diary,” Google, accessed December 3, 2021, https://docs.google.com/document/d/1zigrkIEwmCLq5oM

AkZ-bQIajdwhA9mQezfNAervgIoE/copy.
 16 • Sleep Wellness: Sleep Wellness: Beyond the Guide

Sleep Wellness: Beyond the Guide sleep quality. In the evening, use solely amber-
or orange-colored lights for illumination (fig-
After reviewing each of the items in the Sleep
ure 1.7). For the phone, computer, and TV, utilize
Wellness Guide, synthesize the content with a
apps that filter blue light (the display will appear
deeper understanding of the science behind the
slightly orange). Alternatively, donning a pair of
practices.
amber eyeglasses that block blue light will carry
you into the bedtime hours, reassured that your
Light
melatonin secretion will not be disrupted by, for
Chapter 3 provides elucidation about the role
instance, preparing tomorrow’s lunch in a well-
of light in regulating your sleep-wake cycle,
lit kitchen (figure 1.8). Consider switching to an
while this section provides details about how
orange night-light, in place of bright vanity lights,
to use the timing and quality of light exposure to
to use while brushing your teeth before bed. When
improve sleep health. Sunlight or bright indoor
sleeping, keep the bedroom as dark as possible for
light on the face in the morning is helpful to cor-
the soundest sleep.
rect the circadian rhythm of someone who is not
If someone is a lark, we use an alternate
sleepy until late at night—a night owl—or has a
approach. Falling asleep early in the evening
difficult time waking up at the desired hour. Then,
and awakening before sunrise, a lark is often an
in the evening, establish a routine with reduced
elder, although a small percentage of younger peo-
(or preferably, no) blue/white light exposure two
ple fit this rhythm. Light therapy is used with a dif-
hours before bedtime. This light so close to bedtime
ferent schedule to shift the lark circadian rhythm.
disrupts the circadian rhythm and interferes with
Upon arising, the light levels are kept low, includ-
ing filtering blue light, thus sustaining melatonin
levels for those predawn hours. If the lark engages
in early morning outdoor activities or a morning
commute, sunglasses are essential. Late in the
afternoon and into the early evening, bright light
is used to keep melatonin levels from building. This
will often shift the lark’s schedule closer to the
desired rhythm.

Exercise
A commitment to movement, especially if it is
enough to get a little sweaty or elevate the heart
rate—even slightly—helps us sleep better. Con-
sider something that you can make a regular part
of almost every day for twenty to thirty minutes.
Movement and consistency, more so than the
time of day or type of activity, are key. If gar-
dening is pleasurable, let that be your sport. If
the convenient time is in the evening, it is bet-
ter for most to have the evening workout than to
skip it due to worries that it is too close to bed-
time. It may take several weeks to have an impact
on sleep, but research suggests exercise increases
Figure 1.7 Cozy amber lighting sleep quality.
 Sleep Wellness: Nighttime Urination • 17

Nighttime Urination
There are several possible ways to eliminate night-
time urination. (This refers to people who inter-
rupt their sleep to get up to urinate, as opposed
to bedwetting, a different problem discussed in
chapter 6.) Maybe you are thinking, “I only get up
once during the night to urinate and go right back
to sleep, so it isn’t a problem.” However, when we
understand sleep architecture, the importance of
its components, and how our eight hours of sleep
must be uninterrupted in order to get the proper
balance of each stage, we will see how even just
Figure 1.9 Elevate your legs
one interruption each night can be a significant
problem (see chapter 2). Let’s help people elimi-
nate nighttime urination so they get the benefits level. By elevating the legs during sitting and taking
of a full night’s sleep. breaks to get movement in the legs, some of this
During the day, fluid accumulates in the legs in fluid is moved from the legs up toward the kidneys
varying amounts depending on physical activity to be urinated out during the day. Otherwise, upon
lying down in bed at night, the fluid in the swol-
len legs, now elevated, moves up into the kidneys,
producing more urine than the bladder can contain
during the night. When working on a computer or
watching television, prop up your legs above the
level of your hips, being sure to provide support for
the lower back (figure 1.9). If sitting for long peri-
ods, get up occasionally, and while standing, lift
the heels to put weight on the toes, then lift the toes
so weight is on the heels. (Hold on to something
if support is needed.) Repeating this several times
helps move fluid out of the legs.
Fluid intake during the day and the evening has
an impact on sleep. Stop drinking fluids ninety
minutes before bed to give the kidneys time to
filter the excess water from your blood. Then uri-
nate immediately before bed to empty your blad-
der. For some people, herbal tea causes increased
urination; however, in other people, it is no differ-
ent than water. If you enjoy herbal tea before bed,
determine if this is an influence by not drinking it
within five hours of bed. After your nighttime uri-
nation is resolved, reintroduce the evening herbal
tea and, if sleep is sound and uninterrupted, enjoy
your tea (as long as it contains no caffeine). Alcohol
also increases urination and is best avoided five
Figure 1.8 Looking cool while blocking blue light hours before bed for this reason (and also due to its
 18 • Sleep Wellness: Nighttime Urination

Figure 1.10 Mid-section view of the male reproductive system

sleep architecture–disrupting properties). Elimi- a warm room—and perceiving a need to urinate

nate caffeine entirely after noon, as it is a bladder even though the bladder is not full. Depending on
irritant. Also examine nutritional supplements and a range of factors, including age, the bladder holds
any protein or workout powders to check for ingre- around two cups of urine and, for most people,
dients with diuretic effects. even more at night. An easy way to determine if
An enlarged prostate is associated with night- the bladder truly needs emptying is to collect the
time urination. This is a gland surrounding part of urine and measure the output. Upon arising in
the male urethra, the tube that carries urine and the middle of the night, urinate into a container
semen (figure 1.10). As men age, there is normal such as a pitcher placed in the bathroom. In the
age-related prostate enlargement that squeezes morning, determine the volume of urine. If it is a
the urethra to varying degrees. This makes it dif- small amount of urine, just a few ounces, perhaps
ficult to completely empty the bladder before bed, the body and mind need to be trained to go back
making it crucial to put all the other strategies in to sleep and not respond to the trigger to get up
place to minimize the need to disrupt sleep for and urinate. However, if well over a cup of urine
urination. Some men also decide to talk to their is produced after putting in place all the strate-
medical doctor regarding various prescription gies mentioned, take this information to a doc-
medications or surgical procedures to treat the tor and discuss what could be causing the urine
symptoms. production. Knowing the amount of urine pro-
If a person addresses the various concerns duced during the night will be helpful in the course
and is practicing all these strategies to elimi- of diagnostics.
nate nighttime urination but finds they are still If you still must urinate at night, be safe by
getting up to urinate, there is a possibility that lighting the way, and at the same time, preserve
the nervous system is responding to a trigger of melatonin levels by using orange lights for illu-
awakening—a snoring partner, an outdoor noise, mination from bedside to the toilet.
 Sleep Wellness: Alcohol • 19

Caffeine and Stimulants in the mornings. From there, determine the latest
Individual responses to caffeine vary widely, but if time in the day your body can clear out the caffeine/
someone is getting poor sleep, advice about when stimulant and allow you to sleep well at night.
to end consumption remains standard. Avoid caf-
feine in all its forms after noon until healthy sleep Alcohol
is achieved and sustained for at least a week. The Under the influence of alcohol, the brain is not able
same is true for guarana, a stimulant found in a to construct a proper night’s sleep. Being relaxed
range of sources, including energy drinks (fig- and falling asleep is not the same as creating health-
ure 1.11). Some folks need to give up caffeine, gua- promoting sleep architecture (see chapter 2). For
rana, and any other stimulants (e.g., theobromine, example, having as little as one serving of wine, beer,
which is found in chocolate) entirely until they get or spirits close to bedtime can cause increased awak-
good sleep. After a satisfying sleep rhythm is main- enings during sleep (even though the person may not
tained for a week, you could consider reintroducing be aware of them), decreased rapid eye movement
stimulants. However, many will find getting good (REM) sleep in the first half of the night, and dis-
sleep for a week without stimulants provides such turbing REM sleep rebound in the latter half. Alcohol
an increase in vitality that there is no need for any on its own is not the challenge to sleep; rather it’s the
stimulants. If you are still craving a boost from timing of its consumption. Avoid alcohol at least five
caffeine or another stimulant, first reintroduce it hours prior to bed so the sleep-disrupting chemicals
before noon and notice if there are changes to sleep get mostly metabolized out of the body before it’s
quality or the refreshed feeling upon awakening time to tuck yourself in for the night. This is a wiser

Figure 1.11 Think about your sleep before reaching for an energy drink
 20 • Sleep Wellness: Nicotine

approach than the close to bedtime “nightcap” that Sleep Diary

is sure to hijack a sound night’s sleep. A sleep diary’s purpose goes well beyond keeping
track of how you sleep. By keeping a good sleep
Nicotine diary, you will notice how daytime habits—exercise,
The double bind of nicotine is that it is a stimulant alcohol, caffeine, TV viewing—and their timing
that will keep us awake if used too close to bedtime, have an impact on sleep. By keeping track of your
but if a person stops nicotine earlier in the evening, sleep habits along with how you feel during the
they will have subtle awakenings during the night day, you will also establish a connection between
due to nicotine withdrawals. However, the latter is sleep quality and daytime mood and performance.
preferable, so cease nicotine use at least five hours Record your data in a sleep diary for two weeks.
before bed. In addition to providing clear motivation to make
To support sleep wellness and overall health, seek changes, this type of biofeedback also fuels the
a local or online smoking cessation program, pref- brain for habit-changing behavior. Use this fill-
erably one with scientifically proven mindfulness able sleep diary† created by one of my sleep science
training, which has shown significant success. Dur- students at Kapi‘olani Community College. You may
ing the process of quitting, practice self-compassion also try one of the many phone apps for tracking
for two reasons. The first is that smoking is one of daytime activities and sleep quality. Daytime activ-
the most difficult habits to change, so it is important ity and mood data are essential to the process, so
to be kind to yourself throughout. The second is that be sure whatever you use also tracks that informa-
neuroscience has proven that self-compassion is tion. People are often surprised by their findings
an effective component of habit-changing. Many after making use of a sleep diary. It shines a light on
communities have a resource such as the Hawai‘i several potential areas for change to improve sleep.
Quitline.* Nationally in the US, there is also smokefree
.gov or 1-800-QUIT-NOW (1-800-784-8669). Ritual
The brain can be rewired to associate behaviors
Nap and sensory input with falling asleep. Decide on a
In the early afternoon, take a ten-to-twenty- before-bed ritual, such as taking a shower, using
minute nap. (See the napping section for details) a soothing naturally scented lotion, reading a
book you read only at bedtime, meditating, sing-
Medications ing, practicing a relaxing breathing technique, or
Sleep is disrupted by many medications, such as listening to an audio book or podcast (figure 1.12).
some antidepressants, over-the-counter sleep
aids, pain medications, antihistamines, and Leg Cramps
even prescriptions marketed to promote sleep. If you experience leg cramps at night, talk with your
Just because a medication puts someone to sleep health-care practitioner to determine if you have
does not mean it creates natural restorative sleep. any electrolyte imbalances or if they can suggest any
Check with your health-care provider to deter- supplements, vitamins, or electrolyte drinks. Main-
mine whether any medications you take may tain sufficient hydration. Incorporate daily exercise.
impact your sleep and for guidance about pros and Gentle early evening stretching, from head to toe,
cons associated with sleep disruption and each helps relieve lower leg cramps because they can be
course of treatment. triggered by tension elsewhere (including up much

* “Hawai‘i Tobacco Quitline,” accessed December 3, 2021, https://hawaii.quitlogix.org/en-US/.

† Shook, Sheryl, “Sleep Diary,” Google, accessed December 3, 2021, https://docs.google.com/document/d/1zigrkIEwmCLq5oM
AkZ-bQIajdwhA9mQezfNAervgIoE/copy.
 Sleep Wellness: Sleep in Bed • 21

Figure 1.12 Bedtime story

higher) in the body. Consider a warm bath with Epsom that keeps you awake. Examples of healthy bed-
salts (magnesium sulfate) before bed. During the time snacks would be milk (can be dairy, almond,
cramp, applying an ice or heat pack or standing and etc.) with whole-grain cereal (low in sugar) or nut
holding a stretch might alleviate some of the pain. butter with crackers (figure 1.13). A small serving
is best because digestion slows down with sleep. If
Snack you have gastroesophageal reflux disease, it is best
Our tūtū (the way we say “grandparents” in Hawai‘i) to skip having food too close to lying down. Time it
and tias (Spanish for “aunts”) knew what they were so it does not aggravate your symptoms.
talking about when they advised us to have warm
milk with honey before bed. Although there is a Sleep in Bed
small amount of tryptophan in milk, which is asso- Use your bed only for sleeping, having sex, reading,
ciated with the cascade that puts us to sleep, and the or listening to a relaxing audio file. Avoid emailing,
carbohydrates in honey clear the way to allow more engaging in social media, or watching television in
of the tryptophan to get into the brain, our sound bed, all of which condition the brain to associate
sleep is probably more due to the calming ritual and the bed with a different level of alertness, inter-
the balanced nutrition of that bit of nourishment. fering with sleep. If you have spent what feels like
The general guideline is to have a little snack close twenty minutes trying to fall asleep, get out of bed,
to bedtime and to include a small amount of fat and do something relaxing like reading a book on the
protein and balance that with carbohydrates, but no couch or listening to a relaxing audiobook until
high-sugar items, which cause a stress response sleepy, and then return to bed.
 22 • Sleep Wellness: Temperature

feet and/or hands with a warm soak or heating pad

is also a quick trick if taking a shower or bath is too
time-consuming or not practical.

Timing
Most adults need around eight hours of sleep
every night, and it is best to go to bed and get up
in the morning at the same time each day, even on
weekends.

Clocks
Figure 1.13 Healthy snack for healthy sleep
Do not have a clock within view of the bed; being
aware of the time triggers a loop of thinking that
Temperature keeps you awake. When awakening in the middle
While most people can sleep in a range of tem- of the night, resist the urge to look at the clock or
peratures, I have had several clients find cooling your phone (both of which should not be near your
the bedroom was the one thing needed to fix their bed or visible) and train your brain to let go of the
sleep. Research shows the ideal sleeping tempera- curiosity about the time.
ture is a surprisingly cool 65–68 degrees Fahr-
enheit (18–20 degrees Celsius). In the wild, the Noise
natural drop in temperature each evening trig- If it is not possible to make the bedroom quiet, use
gers the hypothalamus (see chapter 2) to launch noise-reducing earplugs. There are also phone apps
the cascade that ultimately releases melatonin, and audio files that create relaxing white noise,
telling our bodies it is time to sleep. Taking a such as rain sounds. Running a fan in the room is
warm bath or shower before bed promotes this sometimes enough to mask intrusive noises. How-
cooling by bringing the blood flow to the skin in ever, the brain still processes white noise informa-
response to the heat. Then, after stepping out of tion, so minimizing it is preferable when outside
the bath, the blood on the skin surface works like noises are low enough that you can still sleep.
a radiator to cool the body temperature and send
you into a relaxing sleep. To investigate this phe-
Cognitive Behavioral Therapy for
nomenon, researchers developed a bodysuit with
Insomnia
a layer containing a mesh of tiny tubes of water,
precisely controlled for temperature and region Cognitive behavioral therapy for insomnia (CBTI)
of flow. When wearing the suit, participants’ skin involves meeting with an individual or a group
surface was exposed to heat, yet remained dry. once a week for four to eight weeks. The client is
These experiments showed bringing blood flow to advised on how to change thoughts and behav-
the body surface via temporary superficial warmth iors to increase healthy sleep. The National Insti-
provided core-temperature body cooling and thus tutes of Health (NIH) claims CBTI is safe and
reduced the time participants needed to fall asleep effective.† Many insurance companies cover CBTI,
and improved their sleep quality.* Warming the and research shows it is more effective than sleep

* Roy J. E. M. Raymann, Dick F. Swaab, and Eus J. W. Van Someren, “Cutaneous Warming Promotes Sleep Onset,” American Journal
of Physiology: Regulatory, Integrative and Comparative Physiology 288, no. 6 (June 2005): 1589–97, https://doi.org/10.1152/ajpregu
.00492.2004.
† “NIH State-of-the-Science Conference Statement on Manifestations and Management of Chronic Insomnia in Adults,” NIH
Consensus and State-of-the-Science Statements 22, no. 2 (June 2005): 1–30, https://consensus.nih.gov/2005/insomniastatement.htm.
 Sleep Wellness: Cognitive Behavioral Therapy for Insomnia • 23

circadian rhythm is closer to being set, so

Retrieval Practice you can go to bed fifteen minutes earlier
on that fifth night.
Review all the items on the Sleep
c. After five more days, go to bed fifteen
Wellness Guide along with the
minutes earlier, and continue with this
details in the Sleep Wellness
adjustment every five days until you are
Beyond the Guide section. Get a
going to bed around eight hours before
clear understanding of each item,
having to wake up.
as if you were going to explain it to someone to
During the program, a person may feel
help them improve their sleep. Take a blank piece
worse because they are so tired. Pay extra
of paper or create a blank file on your computer.
attention to light. Use dim or orange light at
Divide the document into three large columns
night and bright light in mornings.
with these three headings across the top: “During
Be safe. Put help in place before beginning.
the Day,” “Before Bed,” “While in Bed.” Put away
Do not do dangerous work, drive, take care of
this textbook and your notes and list as many
children, or anything else that requires your
Sleep Wellness Guide items as you can, along with
full attention to do safely in the early days of
details, under each heading. When you are done,
the program due to the high level of sleep debt.
open up the textbook, look at the Sleep Wellness
3. Stimulus control: A stimulus is something
Guide, and correct any errors on your document
that causes a specific reaction. If you hear
and add in any of the items you missed.
your phone (sound from phone = stimulus),
you walk toward it (walking = response).
medications. CBTI does not have medications’ Stimulus control involves separating sleep-
harmful side effects and also has been shown to related activities in the bedroom from
have beneficial effects extending beyond the treat- wakeful activities in the rest of the home. For
ment period, which is not the case with medica- example, not watching TV, emailing in bed,
tions. One of the paradigms for CBTI involves five or sleeping part of the night on the living
pillars: sleep wellness, sleep restriction, stimulus room couch. Here are the instructions:
control, sleep diary, and actigraphy. a. If you are not sleepy, do not go to bed.
b. If you cannot fall asleep within what feels
1. Sleep wellness: Refer to the Sleep Wellness like twenty minutes, leave the bedroom.
Guide for instructions on this step. c. Listen to an audiobook or do some gentle
2. Sleep restriction: Research shows this works reading by a dim or blue light–filtered
better than medications and has longer- light in a chair or on the couch. Do not fall
lasting effects. In general, the concept is asleep there. When you start to fall asleep,
to be in bed only when sleeping and not to move to your bed.
spend hours lying there trying to sleep. Here d. Use the bed only for sleep, sex, and gentle
are the steps: reading or relaxing audio books.
a. Spend only five hours in bed. Figure out 4. Sleep diary: Refer to the sleep diary section
what time you have to get up and count in this chapter for instructions on this step.
back five hours. Go to bed at the same time This helps pinpoint areas from the sleep
every night. wellness list that need to be addressed. For
Example: Do you have to get up at example, someone could report in their sleep
7:00 a.m.? Then go to bed at 2:00 a.m. diary that they were texting in bed or having
b. After five days, you will be very tired in the a glass of wine before bed, but they did not
evening due to sleep deprivation, but your realize those things could affect sleep.
 24 • Sleep Wellness: Additional Support during Pregnancy

5. Actigraphy: This is not necessary but can follow-up survey indicated that the primary fac-
be helpful. Some clinicians use medical tors disturbing women’s sleep during pregnancy
actigraphy devices, while laypersons might were getting up to urinate; back, neck, or joint
use mobile phone apps that monitor sleep. If pain; leg cramps; heartburn; and/or dreams. Even
using a phone app, temper your connection with all these challenges, there is good news,
to the results and do not become fixated on because most women can mitigate pregnancy-
the data, especially given the significant related sleep problems by implementing strate-
limitations of such phone apps as of the gies listed in the Sleep Wellness Guide along with
writing of this textbook. I have met people the following advice. This section will address the
who became obsessed with their phone importance of sleep during pregnancy, and how to
app sleep data to the point that it caused improve sleep by addressing challenges particular
them anxiety and poor sleep. Also keep to pregnancy.
in mind that the movement of a sleeping There are a range of reasons pregnant women
partner may appear as your movement are driven to be concerned about their sleep. Kathy
during a night’s recording, depending Lee—a University of California, San Francisco,
on the placement of your device and how nursing professor and specialist on pregnancy
easily movement is translated across your and sleep—advises pregnant women to remember
mattress. Both actigraphy and sleep-related that in addition to “eating for two,” they are also
phone apps use an accelerometer to detect “sleeping for two.” One of her studies reported
changes in velocity, providing a record of that pregnant women who get less than six hours
physical activity. The movement patterns of sleep a night have more difficult labors and are
are processed by a computer algorithm that over four times more likely to need a cesarean. A
translates those movements as a state of study by another group, which controlled for other
sleep or waking. All this is in an attempt to factors associated with preterm birth, indicated
verify four things: that poor sleep during pregnancy is associated with
a. Circadian rhythmicity: Going to bed a higher incidence of preterm birth (when a baby
between 9:00 and 11:00 p.m. and getting is born too early). Scientists suggest that preterm
out of bed early in the morning or around labor and births may be related to the increase in
midmorning. These times are part of a prostaglandins found in people getting inadequate
healthy circadian rhythm. sleep.
b. Consolidation: One major block of sleep, One of the disruptions to sleep in pregnancy is
as opposed to something like three snoring. Because even a small increase in weight
hours at midnight and three hours in the multiplies the chance of snoring, a woman who
afternoon. never snored could begin snoring during preg-
c. Sleep schedule regularity: Going to bed and nancy, even with the minimal weight gain required.
getting out of bed at the same every day. University of Michigan researchers recommend
d. Napping: When and for how long the nap is screening and treatment for this, as they found
taken. snoring that begins during pregnancy is associ-
ated with a higher risk of developing high blood
pressure during the pregnancy (gestational hyper-
Additional Support during Pregnancy tension) and preeclampsia. Hypertensive disorders
The National Sleep Foundation’s “Women and during pregnancy can have serious consequences,
Sleep” poll in 1998 showed that 78 percent of so we must make an effort to educate people about
women had more difficulty with sleep dur- the importance of screening pregnant women for
ing pregnancy than any other time. Their 2007 snoring.
 Sleep Wellness: Additional Support during Pregnancy • 25

feasible, some people use different strategies like

‘Ōlelo Hawai‘i considering the timing of alcohol consumption
(Language of Hawai‘i) and “pumping and dumping” breast milk until it
is clear of alcohol before nursing. Please contact
Hāpai is Hawaiian for
a lactation consultant or health-care provider for
“pregnant.” It also means “to
guidance.
support and carry” (figure 1.14).
Strategies for healthy sleep during pregnancy
begin with the list of items on the Sleep Wellness
Guide combined with these additional practices:
Sleeping on the side, compared to on the back,
reduces lower-back strain and takes the weight
of the enlarging uterus off the large blood vessels
vital to baby’s and mom’s circulation. This also is
helpful for the digestive system, freeing it from the
pressure of being beneath the uterus. As often as is
comfortable, sleep on the left side, which is slightly
preferred as it takes the weight of the uterus off the
liver, which is on the right side of the body. Left-
side sleep also provides the best position for blood
flow to the heart and the rest of the body. Early in
the pregnancy is a time to practice building the
habit of sleeping on the side. However, sleeping
all night on the side, especially the same side, is
not necessary and likely would cause discomfort in
the hips and shoulders. Remember that while this
is the optimal position theoretically, the position
itself is not something for the pregnant woman to
worry about. The priority is to get sleep. During
the night, you may awaken to find yourself on your
back, or when falling asleep, you might feel bet-
Figure 1.14 Pele emerging from lava
ter in something other than this prescribed side-
sleeping position. Get comfortable as you wish,
Polls show that a small percentage of preg-
and rest assured that your body will give you a sign
nant women drink alcohol before bed in hopes of
when a move is in order.
improving their sleep, even though there is solid Here are some suggestions for increasing your
research on alcohol’s damaging effects to the comfort when side sleeping. Lying on your side,
fetus. Additionally, as stated earlier, while alco- place a pillow between your bent knees and extend
hol induces what feels like sleep, it is not healthy, that pillow to the feet (figure 1.15). The cushion
normal sleep. It is essential for women to seek between the knees squares the hip alignment,
support to eliminate alcohol during pregnancy and its placement between the feet prevents the
and lactation due to the damaging impact of alco- rotation of the top of the thigh bone (femur) in
hol on fetal and infant development. Infant sleep the hip socket. All this diminishes back strain.
is significantly disrupted by even small amounts As the uterus increases in size, a cushion beneath
of alcohol in breast milk. If giving up alcohol the abdomen in this position is often comfort-
during the breastfeeding months/years is not ing. Body-length pillows may also be a satisfying
 26 • Sleep Wellness: Family Sleep and Bed Sharing

Using research from the fields of medicine and

anthropology, Dr. James McKenna, at the Univer-
sity of Notre Dame, provides resources to guide
families in safe cosleeping practices. He empha-
sizes the need for an infant to be in contact with
the mother’s body during sleep in order to prop-
erly regulate itself, as it did when in the womb. He
is also very clear that bed sharing involves much
thought, discussion, and a commitment from the
parent and also the additional parent—if there
is one—and that bed sharing is not suitable for
everyone. A misperception associated with family
Figure 1.15 Put a pillow between your legs sleep is that the child will grow to be clingy and
more dependent, but sociologists and psycholo-
gists explain the opposite to be true. When a child
luxury. If you experience heartburn, use pillows senses the strong emotional bond of a parent, the
to slightly elevate the head and shoulders in addi- child more easily grows to be independent and
tion to following your health practitioner’s general emotionally secure. One concept behind cosleep-
heartburn treatments. ing is that it fosters an environment where a
Regarding other common pregnancy-related child more confidently differentiates from the
sleep disturbances, see, for example, previous parent.
sections on treatment for frequent nighttime uri- Safe family sleeping requires certain precau-
nation, leg cramps, and unsettling dreams. If there tions and arrangements such as these:
are still challenges, seek out a cognitive behavioral
therapy for insomnia (CBTI) practitioner. CBTI is • Infants should sleep on their back.
the most effective proven technique for insom- • The sleeping surface must be firm and not a
nia and does not have the risks and side effects of pillow.
medications. • The mattress should be as close to the floor
as possible, preferably on the floor.
• There must be no potential for a covering,
Family Sleep and Bed Sharing
such as a blanket or sheet, to fall over their
The baby has arrived—but now, where do they face.
sleep? Babies sleeping in the same bed with par- • There must be no exposure to cigarette
ents is normal in a vast array of cultures all over smoke or nicotine in utero or as an
the world, yet in the US, there continues to be infant.
fervent debate (figure 1.16). Could it be our liti- • There must be no stuffed animals, pillows,
gious society, where legal advisors caution medi- or sheepskins (fluffy items).
cal groups against suggesting cosleeping on the • Do not use water beds, beanbags, couches.
off chance that something could go wrong, or are • There must be no gap between the mattress
there legitimate safety and medical concerns? In and frame or the mattress and wall.
the following discussion, the terms family sleep, • Parents must not use alcohol, drugs, or
family bed, bed sharing, and cosleeping will be used medication that may interfere with their
to refer to the practice of having a baby or child ability to easily awaken.
in the bed or in the immediate sleeping space of • Parents with long hair need to fix it so it
the parent. cannot wrap around the baby’s neck.
 Sleep Wellness: Social Justice and Sleep Wellness • 27

Figure 1.16 Sleeping together

Social Justice and Sleep Wellness

• Parents should ensure that they still Who has the luxury of putting these sleep wellness
experience a good night’s sleep. For practices in place? Who is able to dedicate eight
parents who do not feel they will sleep hours each night to sleep when we have work and
well with the baby in the bed, there are family responsibilities; go to school or work some-
certified-safe cosleeping bed attachments where we can take a nap; make time for exercise;
to consider. sleep in a comfortable bed in a dark, quiet room at
• Breastfeeding helps reduce death from the desired temperature? By now, you are likely
SIDS (sudden infant death syndrome) and clear on the importance of good sleep and its con-
other diseases and is highly recommended nection to how healthy you will be, how good you
in conjunction with cosleeping. If the baby feel emotionally, and even how long you will live.
is not sleeping with their breastfeeding But due to economic injustices and lack of equity
parent or if the parent is extremely obese, around things like race and sexual orientation,
it is safer for the baby to be on a separate many people cannot get adequate sleep. Please
surface from the parent’s bed, but still consider your part in working to help yourself and
adjacent to it (such as in a cosleeping bed everyone get better sleep by reading “Your Next
attachment). Actions for Justice” and chapter 7.
28 • Sleep Wellness: Social Justice and Sleep Wellness

Your Next Actions for Justice

Think of someone in your community who may not have the economic
luxury of creating the conditions for optimal sleep. Perhaps they have to
work two jobs to afford food. Look over the Sleep Wellness Guide and con-
sider how you can meet this person where they are in terms of what is fea-
sible for them to change in order to get better sleep. It might not be possible for them to set aside
eight hours at night to sleep, but maybe there is a safe place at their work where they can take a
ten-minute nap during one of their breaks if they pack a pāreu or sarong in their bag. Get creative
with how you can advise those with less privilege so they can improve their sleep and have more
opportunities for health and success.
 2
The Sleeping Brain
Neuroanatomy, Polysomnography, and Actigraphy

Student Learning intricacies of sleep, let’s first get a fundamental

understanding of the brain, at least in the con-
Objectives text of how it functions when it’s awake versus
After you read this chapter, you will be able to sleeping. This will also be valuable in later chap-
• provide an introductory overview of ters, which will make reference to assorted brain
neuroanatomy structures.
• identify and describe functions of sleep-
related brain structures Brain Anatomy and Physiology
• illustrate both directions of the shift
between sleep and waking states What molecules in your brain had to be released
• list the components of polysomnography for you to make the decision to study this chapter?
(PSG) And how are you managing to hold your head up
• describe rapid eye movement (REM) sleep or read the words on the page? The nervous sys-
and non-REM (NREM) sleep tem carries signals through the body via neurons.*
• determine sleep stages from PSG data These signals cause activity in muscles, glands, and
• construct a diagram of healthy sleep other neurons. Some of the neurons are in the brain
architecture for eight hours of sleep and the spinal cord, which together make up the
• explain actigraphy, including its limitations central nervous system. Others travel throughout
compared to PSG the rest of your body and comprise the peripheral
nervous system (figure 2.1). Sensory information
from things we see, hear, feel, taste, or smell flows
into the body and is processed by the central ner-
Introduction vous system. After the brain has put us to sleep, it
Thanks in part to the availability of phone apps has a simple way of keeping most of that sensory
claiming to measure and analyze sleep, as well as information from awakening us. And while we
an epic assortment of sleep analysis devices for the are sleeping, the brain is actively creating the elab-
layperson to wear, we are experiencing a much- orate sleep architecture that carries us through the
needed increase in the desire to deconstruct and different stages and cascades necessary to secure
explore our own sleep. To help understand the the myriad benefits of a healthy night’s sleep.

* Gordon J. Betts et al., Anatomy and Physiology (Houston: OpenStax, 2013), 12, available at https://openstax.org/books/anatomy
-and-physiology/pages/12-introduction.
 30 • The Sleeping Brain: Brain Anatomy and Physiology

Figure 2.1 Central and peripheral nervous systems

Note to reader: A more comprehensive The nervous system has two classes of cells:
review of brain anatomy and physiology glial cells and neurons. Glial cells provide meta-
is beyond the scope of this book, but this bolic (metabolism = chemical reactions of the body)
chapter will provide enough context and and physical support, while neurons carry the ner-
detail to give an understanding of sleep- vous system’s signals. Glial comes from the Greek
related brain structures and functions. For for “glue.” Scientists chose this term when they
additional brain anatomy and physiology, noticed how numerous these cells were in the brain
see The Brain from Top to Bottom, a web- and mistakenly thought they had no purpose other
site developed by Bruno Dubuc, hosted by than holding the neurons together. Later, it became
McGill University in Canada, and labeled clear that these cells are much more than brain glue
“copyleft” as a part of their desire to and play a crucial role in preventing neurologic dis-
encourage people to freely copy and use orders through their sleep-related housekeeping
their site’s content.* activities. The misinformation surrounding glial
cells did not end with their name. For ages, scien-
tists believed glial cells immensely outnumbered
neurons in the brain. Several studies suggested glial

* Bruno Dubuc, The Brain from Top to Bottom (blog), last modified May 4, 2021, https://thebrain.mcgill.ca/index.php.
 The Sleeping Brain: Brain Anatomy and Physiology • 31

Figure 2.2 Neuron and synapse

cells were ten times more numerous than neurons. (neurotransmitters) or sometimes charged par-
However, in 2016, researchers from the Univer- ticles (ions) move from the first cell (presynaptic)
sidade Federal do Rio de Janeiro and University of to the second cell (postsynaptic). In this way, a
Nevada School of Medicine used a new counting signal, such as one triggered from the aroma of
method and proposed that there are actually fewer your roommate’s cooking, can make you aware of
glial cells than neurons in the brain. In their paper, a delight to come. Meanwhile, another pathway,
they also provided a history of the techniques used triggered by that same aroma, may cause you to
to count glial cells, along with a discussion of the salivate and activate your muscles to get you mov-
problems with the methods used that led scien- ing swiftly toward the kitchen so you can eat and
tists to the wrong conclusions for so many years.* fuel your brain for further studying.
However, there are still some neuroscientists who The four major parts of the brain are the brain-
debate this conclusion. stem, cerebellum, diencephalon, and cerebrum
In contrast to glial cells, neurons use electrical (figure 2.3). The brainstem is continuous with
activity and chemicals to carry signals throughout and superior to (above) the spinal cord. Within
the body. The basic parts of a neuron are the den- the brainstem are the medulla oblongata, pons,
drites, cell body, and axon (figure 2.2). Dendrites and midbrain. Posterior to (behind) the brain-
carry information toward the cell body. From there, stem is the cerebellum. The diencephalon—which
the signal travels to the axon to be transmitted to a includes the thalamus, hypothalamus, and
muscle, gland, or another neuron. The functional epithalamus—sits on top of the brainstem. The
connection between the neuron and the cell of its cerebrum, the largest part of the brain, rests on
destination is called a synapse. Here, chemicals top of the diencephalon.

* Christopher S. von Bartheld, Jami Bahney, and Suzana Herculano-Houzel, “The Search for True Numbers of Neurons and
Glial Cells in the Human Brain: A Review of 150 Years of Cell Counting,” Journal of Comparative Neurology 524, no. 18 (June 2016):
3865–95, https://doi.org/10.1002/cne.24040.
 32 • The Sleeping Brain: Brainstem

Figure 2.3 The brain

Brainstem originating in the reticular formation—contains

With groups of neurons that control breathing, brainstem circuits that send signals to the cerebral
heart rate, and blood vessel diameter, the brain- cortex directly and also via the thalamus to con-
stem coordinates movements such as swallowing, tribute to consciousness (figure 2.4). Sensory sig-
coughing, sneezing, and much more. Pathways of nals along this pathway keep you alert and oriented
sensory and motor information pass through and to your surroundings. The RAS is activated during
sometimes make connections in various regions awake states and is inactivated as part of initiating
of the brainstem. The reticular activating sys- and maintaining sleep. However, when someone
tem (RAS)—a network of connections, primarily is sleeping, a strong enough sensory stimulus,
 The Sleeping Brain: Diencephalon • 33

activate RAS pathways and increase their chances

of awakening.

Cerebellum
Although the cerebellum is only one-tenth of the
weight of the brain, it contains almost half of
the brain’s neurons. Many of these neurons are
dedicated to coordinating and optimizing move-
ment, as well as maintaining posture and bal-
ance. While the preliminary motor signal to make
a move, such as throwing a ball or saying a word,
originates in the motor area of the cerebral cortex,
that signal will loop into the cerebellum and back
to the cerebral cortex. The benefit of the cerebellar
input is that the movement will be smoother and
more precise. There are also nonmotor functions
of the cerebellum, such as learning and informa-
tion processing, and a number of sleep-related
functions. Research shows cerebral cortex and cer-
ebellar interactions are crucial for memory con-
solidation, and some of these interactions occur
particularly during sleep.* Cerebellar activity also
changes depending on the specific stage of sleep.
Scientists continue to debate the exact role of the
cerebellum in sleep, but it is clear that its dysfunc-
tion can cause sleep problems. In the presence of
Figure 2.4 The brainstem abnormal cerebellar function due to damage or
a neurologic disorder, the sleep-wake cycle can
such as a loud noise, will awaken the person via be disrupted, and sleep disorders may be present.
RAS activation. People differ from one another in Of interest is that clock genes—regulators of the
the threshold required to activate the RAS during circadian rhythm—are expressed by cerebellar
sleep: thus there are “heavy” and “light” sleepers. cells, but their function in this region remains to
Signals from the eyes, the ears, and most of the be elucidated.
rest of the body (e.g., temperature, touch, pain)
travel through the RAS, but odors do not. This is Diencephalon
why smoke detectors are important in sleeping The thalamus—the largest part of the dien-
areas. A person may die inhaling smoke from a fire cephalon—is a relay station, transmitting sensory
while they are sleeping because the smell of smoke information from the spinal cord and brainstem up
will not travel through the RAS and awaken them. into the sensory areas of the cerebral cortex (fig-
If a person is unable to hear a fire alarm, they may ure 2.5). Additionally, by conveying information
consider smoke detectors that utilize extremely from the cerebellum and other brain structures
bright flashing lights or strong pillow vibrations to up to the motor regions of the cerebral cortex, the

* Cathrin B. Canto et al., “The Sleeping Cerebellum,” Trends in Neurosciences, regular ed., 40, no. 5 (May 2017): 309–23, https://
doi.org/10.1016/j.tins.2017.03.001.
 34 • The Sleeping Brain: Diencephalon

Figure 2.5 The diencephalon shown in a mid-section view of the brain

thalamus is instrumental in creating coordinated Posterior and superior to the thalamus, the
movement. There are also thalamic functions asso- epithalamus contains the habenular nuclei, which
ciated with learning, memory, emotions, and con- associate emotions with smells—for example, the
sciousness. This consciousness is maintained in reaction you may have to the fragrance of your ipo
part by the thalamus transmitting some of the RAS (Hawaiian for “sweetheart”).
signals up to the cerebral cortex. In contrast, dur- The other structure in the epithalamus is the
ing some components of sleep, the thalamus sends pineal gland, a pea-sized structure that releases
oscillatory signals to a large area of the cerebral the hormone melatonin. Hormones are molecules
cortex, in effect interfering with the cerebrocorti-
cal reception of sensory input that would normally ‘Ōlelo Hawai‘i
travel up from the RAS. Oscillatory signals in this (Language of Hawai‘i)
setting refer to neuronal electrical activity that is
regular and synchronized, as opposed to neuronal Ipo is Hawaiian for
sensory activity while awake, which would be irreg- “sweetheart” (figure 2.6).
ular and not synchronized in a widespread manner.
 The Sleeping Brain: Diencephalon • 35

Figure 2.6 Ipo

that flow through the blood to their target structure, being sexually aroused, changing heart rate, and
where they have an effect. This is the mechanism of controlling the circadian rhythm.
action of the endocrine system.* Therefore, the pineal Of the many nuclei in the hypothalamus, the
gland, though it is in the brain, is a part of the endo- suprachiasmatic nucleus (SCN) is the one that orches-
crine system. During the darkness of night, the pineal trates the circadian rhythm. As covered in chapter 3,
gland releases its highest levels of melatonin, thereby the light- and dark-dependent signals from the eyes
regulating the circadian rhythm (see chapter 3). are one of the driving forces of the SCN, which regu-
The hypothalamus (hypo = under) is made up lates the pineal gland’s release of melatonin.
of several nuclei with a vast array of functions. You The posterior hypothalamus (posterior hypo-
may be familiar with the nucleus (plural, nuclei) as thalamic nucleus) is a nucleus that contributes to
the part of a cell that contains the genetic material. an elaborate network of structures involved with
However, in the brain, nucleus refers to a group of maintaining the awake state. One of the molecules
neuronal cell bodies such as those comprising the the posterior hypothalamus releases to sustain
hypothalamus (figure 2.7). To get a sense of the range wakefulness is histamine. This explains, in part, the
of functions of the hypothalamus, they include—but drowsiness experienced when taking an antihista-
are not limited to—regulating body temperature, mine, found in many allergy medications, which
generating the feeling of being satisfied after eating, blocks the effects of histamine. In fact, one of the

* Betts, Gordon J., Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark
Womble, Peter DeSaix. Anatomy and Physiology. (Houston: OpenStax, 2013), 17, https://openstax.org/books/anatomy-and-physiology/
pages/17-introduction.
 36 • The Sleeping Brain: Diencephalon

Figure 2.7 Nuclei of the hypothalamus

wake-producing pathways of caffeine is associ- effects, were inhibited. Since one of the posterior
ated with activating the release of histamine from hypothalamus’ roles is to facilitate the transmis-
these neurons. The posterior hypothalamus also sion of information up to the cerebral cortex, then
releases gamma-aminobutyric acid (GABA) to inhibiting the posterior hypothalamus would sup-
maintain wakefulness. It does this by inhibiting port sleep onset by reducing cerebrocortex informa-
neurons that would normally inhibit cerebral cor- tion processing. The anterior hypothalamus (anterior
tex activity. If you are thinking, “That sounds like hypothalamic nucleus) pulls this off via GABA. When
a double negative,” you are correct. Think of it this the anterior hypothalamus is activated by the neu-
way: The awake cerebral cortex is actively process- rotransmitter serotonin, and if the timing is right
ing information, but that processing can be inhib- in terms of circadian rhythm, the posterior hypo-
ited by neural pathways, thus resulting in sleep thalamus is inhibited by the anterior hypothalamus,
or drowsiness. But if those drowsiness-inducing helping bring about the sleep state. The RAS is also
pathways are inhibited by GABA from the posterior inhibited from the anterior hypothalamus’ GABA
hypothalamus, then the brain will remain alert. activity, further reducing the likelihood that sensory
To understand one of the mechanisms for fall- information will have alerting effects on the cerebral
ing asleep, let’s consider what would happen if the cortex. Now the brain can fall asleep, mostly unin-
posterior hypothalamus, and its wake-promoting terrupted from the outside experience.
 The Sleeping Brain: Cerebrum • 37

Ready to Move On?

Before moving on, explain
how the brain puts you to
sleep. Address the roles
of the anterior hypothalamus, posterior
hypothalamus, reticular activating sys-
tem (RAS), histamine, serotonin, and
GABA. Combine this explanation with
a rough sketch of the brain structures
involved as well as arrows showing the Figure 2.8 Lobes of the human brain
flow of molecules (histamine, etc.).
visualized by creating a space between the meet-
ing of the frontal and temporal lobes (figure 2.9).
Cerebrum The frontal lobe contains areas for motor control,
Singing a song, writing a story, playing a sport, and speech generation, odor identification, reasoning,
planning the day are made possible by our cere- personality, judgment, understanding consequences,
brum. It is divided in half, with discrete regions learning complicated concepts, and more.
that connect the left and right hemispheres. Deep The parietal lobe receives sensory information,
inside the cerebrum are structures associated with such as touch, temperature, pain, and itch. It also asso-
an array of functions including memory, emotions, ciates sensory data with other information, enabling
and motor control. The more superficial neurons you to identify a previously encountered item, such
of the cerebrum comprise the cerebral cortex, as your favorite fruit, entirely by touch. Part of the abil-
which is divided into four lobes: frontal, parietal, ity to understand language is also in the parietal lobe.
occipital, and temporal (figure 2.8). The insula is The occipital lobe processes visual information,
another section of the cerebral cortex but is best including giving meaning to images. For example,

Figure 2.9 The insula

 38 • The Sleeping Brain: Cerebrum

Figure 2.10 The limbic system

image shapes coming from the eyes are combined the limbic system. The hippocampus has received
in the occipital lobe in a manner that allows you more attention in recent decades because studies
to recognize your shoes solely by looking at them. have suggested that the adult hippocampus pro-
The temporal lobe receives and processes duces new neurons, something previously deemed
sounds and has areas for recognizing faces and impossible anywhere in the adult brain. However,
perceiving smells. with further research, neuroscientists began ques-
The insula, previously one of the least under- tioning the existence of hippocampal neurogen-
stood brain regions, is now known to process taste, esis. The debate has continued, with 2019 research
smell, sound, visceral and body surface sensations, swinging the view back in favor of neurogenesis in
and emotional responses such as empathy. adult humans up to ninety years of age.*
The limbic system includes part of the cerebral In later chapters, we will revisit assorted aspects
cortex and contains groups of neuronal cell bodies of brain anatomy, such as when learning about the
and pathways that interconnect cerebral cortex creation and qualities of different types of dreams
regions and other brain structures (figure 2.10). It or how dreams can help us heal from trauma. For
creates emotions such as pleasure, anger, and rage now, our discussion of brain activity will turn to
while also sparking drives for hunger and sex. The how its characteristics are used to classify different
hippocampus, a vital structure for memory, is in waking and sleep states.

* Elena P. Moreno-Jiménez et al., “Adult Hippocampal Neurogenesis Is Abundant in Neurologically Healthy Subjects and Drops Sharply
in Patients with Alzheimer’s Disease,” Nature Medicine 25, no. 4 (March 2019): 554–60, https://doi.org/10.1038/s41591-019-0375-9.
 The Sleeping Brain: Electroencephalogram • 39

Figure 2.11 Polysomnogram

Polysomnogram polysomnogram (poly = many, somno = sleep,

gram = recording; figure 2.11).
The polysomnogram (PSG) is the scientific tool
for verifying sleep and is also used clinically to
Electroencephalogram
analyze sleep for disorders. While phone apps
During an electroencephalogram (EEG; electro
and actigraphy (see Actigraphy section) are com- = electricity, en = inside, cephalo = head, gram =
monly used to report sleep data of varying value, recording), electrical activity in the brain travels
the scientific community has agreed to physi- through the skull and skin and can be detected by
ologically define sleep in humans as a set of pasting tiny electrodes to the scalp (figure 2.12).
stereotypical electrical signals from the brain, Viewing the voltage changes across time gives
eyes, and skeletal muscles. Together, these three an indication of sleep onset and offset as well as
measurements—electroencephalogram, electro- the stage of sleep (such as REM or NREM, covered
oculogram, and electromyogram—comprise the in the following section). The voltage change is
 40 • The Sleeping Brain: Electroencephalogram

Retrieval Practice
Put away the book and all your
notes. Make some very rough
sketches of the brain, including all
the parts covered in this chapter.
This will take more than one sketch
because some of the regions are on the outer areas
and some are deep inside the brain. For example,
one sketch should show the major lobes of the
cerebral cortex (outer regions), while another
sketch should show the details of the dienceph-
alon (deep regions), and there will be additional
sketches as well. After you have sketched as many
parts as you can recall, add arrows with words
describing the functions of each of the regions.
Take a moment to congratulate yourself for all
you were able to create, and then go back to the
chapter and add in any missing structures and
functions on your sketches while also correcting
any of your errors. You may find you need to make
Figure 2.12 Baby connected to EEG additional sketches to include all the structures
you find on that second pass through the chapter.

measured vertically along the y axis, and the time

change is measured horizontally along the x axis.
This axis orientation is typical for all three types
of polysomnogram recordings (electroencepha-
logram, electrooculogram, and electromyogram),
but the scale on the y axis may vary.
The PSG electrical wave characteristics are
amplitude, frequency, and morphology (fig-
ure 2.13). Wave amplitude is exactly what it sounds
like: the size of the wave—a y axis measurement of
voltage. Frequency describes how fast the waves are
coming, so will be measured by looking along the x
axis, at timing (figure 2.14). The units for frequency
are measured in hertz, also known as “cycles per
second,” with a cycle being an entire wave. So this
refers to how many whole waves are arriving every
second. (The term hertz [Hz] was named after a
person who studied electromagnetic waves.) Mor-
phology (morph = form) is a way to look along the
recording for unique shapes, such as a sleep spindle Figure 2.13 Wave amplitude and frequency as well as
or K-complex, which are discussed in relation to a K-complex and sleep spindle
 The Sleeping Brain: Electrooculogram • 41

Figure 2.14 Waves in Hawai‘i

Figure 2.15 Riding the perfect wave

NREM 2 in the Sleep Stages section (figure 2.15). Theta: drowsiness, daydreaming, sleep; 4–7 Hz
Different physiological states, such as sleeping or Delta: sleep; 1–4 Hz
thinking, can be identified by EEG (figure 2.16).
Electrooculogram
Beta: awake, alert, thinking; 14–40 Hz Different parts of the sleep cycle have particular
Alpha: awake, resting the mind, eyes closed; eye movements that can be recorded by pasting
8–13 Hz electrodes on the skin beyond the outer corner of
 42 • The Sleeping Brain: Electromyogram

Figure 2.16 EEG recordings

each eye for an electrooculogram (EOG; electro = picked up by an EMG. During a night’s sleep, it
electricity, oculo = eye, gram = recording). The is normal to change position, twitch, and even have
anterior (front) region of the eyeball is positively periods of paralysis. The EMG displays the type and
charged compared to its posterior (back) region. timing of this movement (or lack of movement) so
This charge difference is utilized to generate a volt- that data can be combined with the EOG and EEG to
age trace for each eye, indicating if the eye is moved provide details about a person’s sleep.
toward or away from the electrode, as well as the
speed and size of the movements (figure 2.17). Additional Clinical Measures
The EEG, EOG, and EMG are useful in research, but
Electromyogram a clinical sleep study relies on additional physi-
Body movement during sleep can be categorized ological data. The sleep technician will connect the
to determine sleep stages. Electrodes are typically patient to devices to measure heart activity (elec-
placed below the chin and on the leg for an electro- trocardiograph), blood oxygen (pulse oximeter),
myogram (EMG; electro = electricity, myo = muscle, breathing effort (chest and abdominal expansion
gram = recording). If you are sitting up reading this measurement instruments), and breath movement
chapter and start to fall asleep, your head would at the mouth and nose (oral/nasal airflow sensors).
fall slightly forward because the postural muscles See the Apnea section of chapter 6 for a further
below the chin relax. This change in muscle tone is discussion of these clinical measures.
 The Sleeping Brain: Additional Clinical Measures • 43

Your Next Actions for Justice

Who can afford a clinical sleep study? Polysomnography and its interpretation
require dedicated resources, but there is an enormous return on investment.
Most importantly, a clinical sleep study could save your life, especially if you
have something like sleep apnea, discussed in chapter 6. From a business
standpoint, making these studies accessible could save insurance companies and taxpayers money.
We know poor sleep can cause diabetes, cardiovascular disease, neurologic disorders, and more.
These are expensive diseases that can require decades of treatment for each patient. If a clinical
sleep study determines there is a sleep disorder and it is treated, that patient will reduce their
odds of getting other diseases that could cost insurance companies and taxpayers more money
than treating a sleep disorder. Since clinical sleep studies make sense in terms of saving lives and
dollars, thankfully insurance usually covers them. However, lack of access to affordable insurance
can be an obstacle for someone who needs one of these studies. In your community, where can
someone go for medical care if they do not have health insurance? Your homework is to check the
internet and ask around to find out what open-access resources are available for health care in your
neighborhood? Make a note on your phone or on a piece of paper in your wallet so if you are shar-
ing sleep wellness information with someone who cannot afford medical care, you can tell them
where to find it in your area. In Hawai‘i, we have Waikīkī Health,* which provides medical services
to everyone, regardless of their ability to pay.

* “Waikiki Health,” accessed on December 3, 2021, https://waikikihc.org/.

Figure 2.17 Polysomnography set-up and data

 44 • The Sleeping Brain: Sleep Stages: REM Sleep and Non-REM Sleep

Sleep Stages: REM Sleep and vessels of the iris to the cornea, which lacks blood
Non-REM Sleep vessels.* During sleep, if the eyes did not move,
the lack of aqueous fluid movement could result in
Sleep is divided into five major stages, each with
corneal suffocation and cell death. When a person
an assortment of characteristics that distinguishes
is awake, with the eyes open, there is a temperature
one stage from the other. However, they are named
difference on either side of the cornea that creates
simply in reference to the presence or absence of
convection currents, causing the aqueous humor
rapid eye movement (REM). Curiously, REM sleep
to move and transport the oxygen (figure 2.18).
has only brief periods of rapid eye movement,
The story gets more interesting when we try to
but that name has persisted through the decades.
understand why periods of REM sleep get longer
Non-REM (NREM) sleep is further divided into
throughout the night. The Columbia researcher’s
four stages: NREM 1, 2, 3, and 4. Each of the five
group theorized that this lengthening of the REM
sleep stages occurs and repeats during different
sleep periods is necessary for oxygen transport, as
parts of a night’s sleep, comprising the full sleep
the cumulative time (NREM + REM) the closed eye
cycle. The order, timing, and duration of the stages
remains motionless increases from the first to the
are referred to as sleep architecture. We will see
last hour of sleep.
that the brain has quite a job to do if it is to build a
Looking at the EEG of a person in REM sleep
healthy night’s sleep according to the sleep archi-
may lead you to believe they are awake because the
tectural blueprint, which has been perfected over
electrical activity is asynchronous—it looks messy.
millennia.
This asynchronous activity is typical of the waking
state, when the brain is processing myriad sensory
REM Sleep
input and thoughts.
During REM sleep, we have vivid and emotional
The flaccid paralysis of skeletal muscles during
dreams while the body is paralyzed and not appar-
REM sleep leaves the person motionless except for
ently regulating several physiological functions
breathing, rapid eye movement, and the occasional
such as body temperature, heart rate, and blood
twitch, perhaps in a leg, finger, or facial muscle.
pressure. REM sleep is composed of phasic and
There are also tiny skeletal muscles in the middle
tonic components. Phasic REM sleep is easily rec-
ear—providing protection from loud noises—that
ognized due to the “phases” when the eyes are
darting back and forth. Tonic REM sleep, while still
considered REM sleep, does not have eye move-
ments but has similar brain activity to phasic REM
sleep. Unless otherwise noted, in this textbook,
REM will refer to REM in general without differ-
entiating between phasic or tonic.
The purpose of those rapid eye movements may
surprise you, especially if, like many others, you
assumed the movements were associated with
dream content (which they are not). Research by
a Columbia University ocular physiologist suggests
that rapid eye movement during sleep may be a way
to keep the aqueous humor in the eyeball swirl-
ing in order to transport oxygen from the blood Figure 2.18 The eye

* “New Research Suggests REM Is about Eyes Not Dreams,” Columbia University Irving Medical Center, Columbia, accessed May 5,
2021, https://www.cuimc.columbia.edu/news/new-research-suggests-rem-about-eyes-not-dreams.
 The Sleeping Brain: NREM Sleep • 45

are not paralyzed during REM sleep, but this is

certainly not observable to the casual viewer. Fig-
ure 2.19 shows the EEG, EOG, and EMG of the wak-
ing state and different stages of sleep: S1 (NREM 1),
S2 (NREM 2), SWS (slow-wave sleep; NREM 3 and
NREM 4), and REM.

NREM Sleep
NREM 1 is how you enter sleep and is a light stage
of sleep. Light sleep means a person is easily awak-
ened. Many of us have been on one end of this expe-
rience: You wake up your friend, who is obviously Figure 2.19 EEG, EOG, and EMG
sleeping, and you thoughtfully mention, “Sorry to
wake you, but—” and they interrupt, “I was not in NREM 1 and are seen in the EMG. This
sleeping!” and look at you like you said something stage can also include hypnic jerks, where
ludicrous. If your friend happened to be hooked the entire body or body parts have a large
up to PSG, you would be able to show them they twitch, and there is often a sensation of
were in fact asleep. They may report they could falling. There is speculation that hypnic
not have been asleep because they were thinking jerks are a vestigial response that prevented
about something, although usually something quite our ancestors who slept in trees from falling
mundane. These “thoughts” are in fact the dull to the ground.
dreams of NREM 1. Another experience of NREM 1
can be when we lie down to sleep, and after a few The term light sleep often refers to NREM 1
moments, wonder why we were thinking some- and NREM 2, but NREM 2 sleep, where you will
thing slightly absurd or illogical. We likely fell into spend almost half of your night, is more difficult to
NREM 1, easily awakened with no impression of awaken from than in NREM 1. This is when things
being asleep, and then recalled the NREM 1 dream in the body start to slow down:
as a “thought.”
Here are some more facts about NREM 1 sleep: • The unique EEG morphology—sleep
spindles and K-complexes—of NREM 2
• The EEG of NREM 1 is characterized by theta makes it easy to differentiate this stage
activity, with its lower frequency compared of sleep from the others (figure 2.20).
to the awake state. Sleep spindles may be associated with
• Although you may freak out your roommate learning, and transferring information
by staring at them while they fall asleep
(the sleep scientist’s folly), you can note
when they drift into NREM 1 as their closed
eyes have easily observed slow rolling
movements.
• Occasionally, we see someone lying down,
gently readjusting their position, and we
conclude they are not sleeping. We may say
something to them, to find they startle a
bit and ask why we awakened them. These
seemingly wakeful movements are normal Figure 2.20 NREM 2 EEG
 46 • The Sleeping Brain: Sleep Architecture

from short-to-long-term memory. functions, such as temperature and blood pres-

K-complexes are generated in response to a sure? Ultimately, most have landed on considering
stimulus, such as touch or sound, and may SWS deep sleep due to the synchronous slow-wave
help us stay asleep during those potential brain activity and the difficulty of awakening a per-
disruptions. son from this stage, compared to the asynchronous
• The eyes do not have any noticeable brain activity of REM sleep and the relative ease of
movements during NREM 2. awakening from REM sleep.
• There may still be some body movements
during NREM 2, such as shifting position.
Sleep Architecture
NREM 3 and NREM 4 together are often referred Sleep architecture is the timing and order of each
to as “deep sleep” because awakening from these of the sleep stages: REM and NREM 1, 2, and 3.
stages is difficult and results in a fierce feeling of Your brain and body are building something com-
grogginess. plex while you are lying there, and even some-
thing seemingly minor like a glass of wine shortly
• The EEGs for NREM 3 and NREM 4 both before bed is enough to disrupt your brain’s abil-
contain large amplitude, slow waves—delta ity to create all the elements of sleep. Alcohol, a
waves—giving both of these sleep stages central nervous system depressant, is one of the
the name “slow-wave sleep.” NREM 4 many substances that can prevent the brain from
consists almost entirely of these slow generating some of the sleep stages, such as REM,
waves, while NREM 3 has intermittent and can wreak havoc on the body’s ability to orga-
periods of the slow waves. Because this nize the stages in a manner necessary to receive
percentage of slow-wave sleep is the most the benefits of a healthy night’s sleep.
noticeable difference between NREM 3 and Sleep begins with NREM 1 and then moves
NREM 4, many scientists have abandoned through NREM 2 and 3 before going into the first
use of NREM 4, stating that NREM has only period of REM, and this completes the first sleep
three stages, 1, 2, and 3. For simplicity and cycle. On the way from NREM 3 to that first REM
clarity in this text, we will use slow-wave period, there may be some time in NREM 2 and 1.
sleep (SWS) to refer to NREM 3 and NREM 4 This first cycle takes about ninety minutes and will
collectively, collapsing NREM 4 into NREM repeat throughout the night around five times,
3 when discussing the NREM stages. resulting in around 7.5 hours of sleep (consider
• The eyes do not have any noticeable
movements during SWS.
Retrieval Practice
• Some body movement may occur during
SWS, but it is minimal. After viewing the sleep archi-
tecture figure and studying the
Some researchers debated the use of the word discussion of how sleep stages
deep when referring to slow-wave sleep, so occa- progress through the night, set
sionally an article may seem contradictory to aside the content and do not let
the convention. Which would you consider deep yourself look at it. On a piece of paper or using
sleep: SWS, during which the body may be moving your computer, create a rough sleep architecture
slightly and is still regulating many of its physi- sketch of an eight-hour night’s sleep. Then open
ological functions, such as temperature and blood up the book and your notes and make corrections
pressure, or REM sleep, when the body is para- to your drawing.
lyzed and not highly regulating some physiological
 The Sleeping Brain: Actigraphy • 47

Figure 2.21 Hypnogram of sleep between midnight and 6:30 am

doing that math to convince yourself it makes the phone is being held. In general, an accelerometer
sense). The hypnogram in figure 2.21 shows sleep detects a change in the speed, direction, and size
architecture. Around midnight, this person took a of a movement. Actigraphy utilizes accelerometers
few minutes to fall asleep (sleep-onset latency), in small, watch-like devices to record a person’s
went into NREM 1 (stage 1), and then went through physical activity, and consequently, in combination
each of the night’s sleep cycles before ultimately with computer algorithms, can be used to examine
awakening fully at 6:30 a.m. sleep in clinical and research studies (figure 2.22).
Within each ninety-minute cycle, as it repeats The idea behind actigraphy is that during long
during the night, REM increases and NREM 3 and enough periods of inactivity, a person must be
4 decrease. Another way to think of this is that sleeping, so that period would be labeled as sleep.
during the beginning of the night, you are getting Usually, the device will have a button that can be
more NREM 3 and 4, and during the last part of pressed when the person goes to bed and awak-
the night, you are getting more REM. Putting it all ens. That context is helpful because sitting for two
together, we also see that almost half the night is hours watching television could also seem a lot
spent in NREM 2. (Note how the example hypno- like sleep to an accelerometer. Polysomnography,
gram differentiates between NREM 3 and NREM 4 with the three physiological measures of EEG, EOG,
[as stages 3 and 4], while in this textbook, those and EMG, has been used to validate actigraphy.
two stages are typically merged into NREM 3.) However, it is important to understand actigra-
phy’s limitations. In actigraphy, we are using a
device to measure movements and then making
Actigraphy a leap utilizing computer programming to label
Cell phones contain a tiny instrument, an accel- different periods as sleep, while PSG is measuring
erometer, that changes the view on the phone the actual elements (EEG, EOG, and EMG) used in
display—the screen rotation—depending on how defining sleep.
 48 • The Sleeping Brain: Actigraphy

Figure 2.22 Actigraphy device and data from a college student

The different measures and derivatives from enough times in the night that it added up to one
actigraphy are as follows: hour of being awake (one hour of WASO). That
would equate to seven hours of sleep during that
Sleep latency: how long it takes to fall asleep eight-hour period. Dividing seven by eight gives a
Wake after sleep onset (WASO): how much time, healthy sleep efficiency of 88 percent. Upon seeing
after falling asleep, was spent awake their actigraphy data for the first time, many of
my sleep science lab students are shocked by how
Total sleep time: from sleep onset to final
many times they woke up during the night and
awakening, with WASO subtracted
even more surprised that it is considered normal
Sleep efficiency: total sleep time divided by the and healthy. We are rarely aware of any of these
total time between sleep onset and final awakenings.
awakening; often referred to as sleep quality What about a sleep efficiency of 100 percent—
and why is that not included in the healthy range?
Sleep latency should be at least fifteen min- With normal sleep architecture and a reasonable
utes, as discussed in chapter 1, but certainly, much amount of sleep debt, a person would still occa-
beyond that can begin to be frustrating. Sleep sionally awaken, as noted previously. However, if a
efficiency should be between 85–95 percent. To person has a sleep disorder or an extreme amount
make this relatable, imagine that during the eight of sleep debt, they may not awaken at all during
hours between falling asleep and waking up in their night’s sleep and have a sleep efficiency close
the morning, you were awake for a few minutes to 100 percent.
 3
Circadian Rhythm

Student Learning Circadian Rhythm and Sleep Pressure

Don’t Always Agree
Objectives
There are brain cells that drive your body to go
After you read this chapter, you will be able to through an activity cycle that is roughly twenty-
• explain the difference between circadian four hours in duration. The cycle is your circadian
rhythm and sleep pressure rhythm, and those brain cells are like a clock inside
• illustrate the actions of structures and your body. Almost every creature on earth has a
molecules that generate the circadian similar cycle; even plants and insects exhibit these
rhythm rhythms.
• describe the effects of light, shift work, The 2017 Nobel Prize was awarded to research-
jet lag, and caffeine on the circadian ers who figured out how genes in the fruit fly cre-
rhythm ate a rhythm of cell activity that is approximately
• compare polyphasic sleep with biphasic twenty-four hours. They also clarified how similar
sleep mechanisms are utilized in human cells to cre-
ate our biological clock. The internal clock pro-
vides the daily timing for sleep, body temperature,
Introduction blood pressure, mental clarity, bowel movements,
hormones, athletic performance, and more (fig-
Why are you lying awake, staring at the ceiling?
ure 3.2). And while light and dark have a signifi-
It’s 10:00 a.m. and you stayed up all night to study
cant impact on this circadian rhythm, the cycle
for an exam, arrived at your early morning class
thinking about nothing more than how quickly you
could get back to your bed, completed the exam
in spite of the occasional head bob, then rushed
home to at last jump into bed (figure 3.1). Yet there
you are, not only having flashbacks from the exam
pages but also criticizing yourself for something
silly you said to your crush as you were leaving the
classroom. In other words . . . you are wide awake!
You can thank your circadian rhythm.

Figure 3.1 Nodding off

 50 • Circadian Rhythm: Circadian Rhythm and Sleep Pressure Don’t Always Agree

Figure 3.2 Circadian rhythm

will persist even if a creature is in total darkness By staying up all night, sleep pressure builds con-
for days.* tinuously until we have to struggle heartily to stay
Your body has another process that controls awake. But circadian rhythm drives the brain and
whether or not you are sleepy: sleep pressure, the body to be alert in the midmorning hours, even if we
drive to sleep depending on how long you have been are sleep deprived. You likely have also experienced
awake. Your brain breaks down adenosine triphos- this circadian rhythmicity on a day when, after a
phate (ATP) to get energy (figure 3.3). This reaction perfectly sound night’s sleep, you find yourself feel-
causes an accumulation of adenosine. Every hour ing quite drowsy around 2:00 p.m. This is the inter-
you are awake, adenosine builds up, binds to ade- nal clock of your circadian rhythm giving you the
nosine receptors, and activates sleep-promoting healthy body signal that it is nap time (figure 3.4).
regions of the brain, while at the same time, ade-
nosine inhibits alert-promoting brain regions.
Through these pathways, adenosine puts “pres-
sure” on the brain to go to sleep. During sleep, ade-
nosine will get broken down, recycled, and removed
from the brain, so your sleep pressure drops to its
lowest point during the final minute of your sleep.
Then with each waking moment, sleep pressure
continues to build, and the cycle continues.
As you likely guessed from our all-nighter sce-
nario that left you wide awake at 10:00 a.m., circa-
dian rhythm and sleep pressure have an interaction. Figure 3.3 ATP chemical structure

* “The 2017 Nobel Prize in Physiology or Medicine—Press Release,” Nobel Prize, accessed May 28, 2021, https://www.nobelprize
.org/prizes/medicine/2017/press-release/.
 Circadian Rhythm: How Many Hours Are in a Day? • 51

‘Ōlelo Hawai‘i
(Language of Hawai‘i)
Ana is Hawaiian for “cave”
(figure 3.5).

Figure 3.4 Circadian rhythm vs. sleep pressure

One of their primary interests was what we
now call the circadian period—the time it takes
How Many Hours Are in a Day?
to complete one cycle of the circadian rhythm.
In 1938, two sleep science pioneers were so In other words, away from the influence of light
intrigued by the sleep-wake cycle that they spent and other cues that tell us when a day begins and
a month 140 feet (over 42 meters) below ground in ends, how long would it take for the body to go
Mammoth Cave in Kentucky. There was no outside through a cycle of its natural biological rhythms
light, and the temperature remained at 54 degrees before starting over for the next “day.” These Uni-
Fahrenheit (12 degrees Celsius) in the ana (Hawai- versity of Chicago researchers, Professor Natha-
ian for “cave”). nial Kleitman and his student Bruce Richardson,

Figure 3.5 The cave behind Waiānuenue Falls

 52 • Circadian Rhythm: Sunlight, Larks, and Night Owls

recorded, among other things, fluctuations in body sunrise. We will turn our attention to sunlight to
temperature, hoping to gain insight into the body’s explain why we are saved from that daily shift in
internal connection to the twenty-four-hour day our schedule.
(figure 3.6). “Internal” in this case refers to some-
thing that would drive the circadian cycle without
Sunlight, Larks, and Night Owls
any external cues, such as daylight. Based on sleep-
wake cycles and body temperature fluctuations, Thankfully, sunlight has a strong influence on our
they found their biological rhythms were in fact circadian rhythm. Exposure to light in the morning
longer—by one to four hours—than twenty-four synchronizes it with our planet’s solar cycle, thus
hours. We now know they were on track with this trimming those fifteen minutes off our circadian
conclusion, as given a setting not influenced by period. Even artificial light, social activity, noise,
external cues such as light, the human circadian temperature, and food impact our internal clock
period is about twenty-four hours and fifteen (figure 3.7). These cues are called zeitgebers, from
minutes. This means that left to our own devices, the German for “time givers.” Part of the success
each night, we would fall asleep fifteen minutes of Kleitman and Richardson’s work in the cave was
later. After just eight days of this, rather than fall- due to their being away from major zeitgebers,
ing asleep at midnight and arising at 8:00 a.m., so they could experience what the internal clock
those times would shift to 2:00 a.m. and 10:00 a.m. would do in the absence of most external influ-
The time shift would continue this way forever. ences. Being isolated from zeitgebers puts a person
Eventually, you would be falling asleep in the late in a “time-free” environment. They do not know
afternoon and awakening several hours before the time of day or night or even how many days
have passed.
In the decades since Kleitman and Richardson,
circadian rhythm studies have often emphasized
the importance of time-free settings in order to
substantiate the theory of the internal clock work-
ing on its own. In some protocols, male participants
are directed to shave their faces at varied intervals
so their “five-o’clock shadow” will not provide
any clues about the time of day or number of days
passing. In the absence of these types of zeitge-
bers, numerous investigations have verified that
our clock signal is generated inside of us (endog-
enous), but where exactly is its control center?
Animal studies have demonstrated that the
suprachiasmatic nucleus (SCN), a tiny structure in
the brain, is necessary and sufficient to create the
circadian rhythm (see chapter 2). Scientists removed
the SCN from animals that previously exhibited
healthy circadian rhythms, and their rhythmicity
disappeared, suggesting the SCN is necessary to
generate the circadian rhythm. Another procedure
involved transplanting the SCN from one animal to
another. The SCNs from animals with long circa-
Figure 3.6 Circadian rhythm of physiological measures dian periods (more than twenty-four hours) were
 Circadian Rhythm: Sunlight, Larks, and Night Owls • 53

rhythm–setting molecule that tells your brain it is

time to sleep. Then when light shines on the eyes,
an electrical signal travels along the optic nerve to
the SCN—our internal clock—which is also a part
of the hypothalamus. In the presence of light, espe-
cially sunlight and blue light, the SCN sends a signal
to the PVH and inhibits the melatonin-producing
pathway. This lets our brain know it is time to be
awake. We are diurnal (active during the day), so this
pathway keeps us alert during the daytime hours. In
a nocturnal (active at night) animal, the melatonin
release/inhibition pathway is similar to ours, except
opposite in one regard: the response to light is to
induce sleep and the response to dark is to bring
about alertness and activity.
Since this pathway of disrupting melatonin
secretion begins with light shining on the eye, it
can be surprising to find that some blind people
do have their circadian rhythm entrained to the
sunlight. It is because not all the cells in the retina,
a layer of tissue lining the inside of the back of the
eye, transmit visual signals: some ganglion cells
carry light-signal information from other retinal
cells to the brain for processing visual images. But
Figure 3.7 How many zeitgebers do you see in this another type of retinal ganglion cell contains mela-
photo? nopsin, a light-sensitive pigment, and in addi-
tion to responding to light themselves, these cells
transplanted into animals with short circadian peri-
ods (less than twenty-four hours), and vice versa. Ready to Move On?
Consequently, the animals’ circadian rhythms
In philosophy, law, math,
shifted to be aligned with their new SCN, imply-
and more you may encoun-
ing the SCN is sufficient for generating circadian
ter comparisons of neces-
rhythm. But the SCN is only one structure along
sity and sufficiency. Before moving on,
the pathway of signals that keeps the body on the
consider the necessity and sufficiency of
approximately twenty-four-hour rhythm.
the SCN to produce the circadian rhythm.
In the dark, a signal from the paraventricu-
Then explore some educational websites
lar nucleus of the hypothalamus (PVH) activates to help you create—in your mind—a sce-
a circuitous pathway to the melatonin-releasing nario you could use to explain to someone
cells of the pineal gland (figures 3.8 and 3.9). The the relationship between necessity and
signal travels from the PVH, down into the upper sufficiency. Also consider how under-
thoracic region of the spinal cord, through the standing the difference will help you think
superior cervical ganglion (a little ball of neurons more critically when reading someone’s
in the neck), and finally up to the pineal gland, claims about causation.
causing it to release melatonin, which is a circadian
 54 • Circadian Rhythm: Sunlight, Larks, and Night Owls

Figure 3.8 Neuroanatomy of the circadian system

carry the light information to the SCN for circadian maintain their circadian rhythm in sync with the
rhythm light entrainment. sun. However, it is important for these individuals
In other words, there are different types of to wear dark sunglasses in daylight because they will
retinal ganglion cells, which perform different not have the pupillary constriction (the shrinking of
functions. If a person’s blindness was caused by the pupil) that would protect their retina from the
something that left the melanopsin-containing sun’s damaging rays. For some blind people, their
ganglion cells functioning, they will be able to melanopsin-containing ganglion cells do not func-
tion, so sunlight does not regulate their circadian
rhythm and thus they struggle more with maintain-
ing a twenty-four-hour circadian rhythm. The US
Food and Drug Administration and the European
Medicines Agency have approved a drug that acti-
vates melatonin receptors as a treatment, and some
research also suggests that melatonin supplements,
Figure 3.9 Light and dark impact the pineal gland’s when dosing and timing are appropriate, improve
release of melatonin circadian rhythmicity in blind people.
 Circadian Rhythm: Sunlight, Larks, and Night Owls • 55

Figure 3.10 During the winter, the sun does not rise at all in Tromsø, Norway

In some parts of the world with short periods the night owls (“night people”), fall asleep after
of daylight in winter, circadian rhythm disrup- midnight and wake up much later in the morn-
tions are understandably more common and are ing, maybe as late as noon (figure 3.12). These are
often associated with poor sleep quality (fig- two different chronotypes (a word that comes from
ure 3.10). Complicating the situation is seasonal khronos, the Greek word for time). While sometimes
affective disorder (SAD), a type of depression that these bedtime patterns are age-related, such as the
most often begins when the weather becomes elderly lark or teenage night owl, chronotype is also
cloudier (blocking the sun) and/or daylight peri- a gene-based timing pattern for when a person
ods get shorter. There are interactions between naturally feels sleepy. The genetically determined
the circadian rhythm pathway and pathways that chronotype usually persists regardless of age.
involve the release of molecules like thyroid and
serotonin, which affect mood. The association of
depression with poor sleep further compounds
the challenge of SAD. In these regions with darker
days, it is helpful to incorporate various forms of
light therapy, including working in front of light
boxes and installing classroom lights that simulate
a bright spring day at noon (figure 3.11).
Regardless of where they live, some people find
their circadian rhythm is naturally shifted so they
fall asleep in the early evening and wake up before
dawn. These folks are sometimes referred to as
larks (“morning people”), while their counterparts, Figure 3.11 Bright lighting in the classroom
 56 • Circadian Rhythm: Derailing the Circadian Rhythm

This is not much solace for night owls who have

to catch the bus at 6:30 a.m. to get to an 8:00 a.m.
class, but there are coping strategies. Chapter 6 con-
tains a discussion of these circadian rhythm disor-
ders, referred to as advanced sleep-wake phase (in
larks) and delayed sleep-wake phase (in night owls).
Tips for working with each of these disorders are in
chapter 1, which also includes details about orange
versus blue light (such as from a computer screen)
and their effects on the circadian rhythm.

Derailing the Circadian Rhythm

For those who are neither larks nor night owls,
there still are plenty of challenges to maintain-
ing the circadian rhythm. And deviating from the
earth’s rotational rhythm and natural daylight
hours comes at a great cost. Even a once-a-year
shift forward in the clocks can be deadly, as seen
in the US with the significant increase in deaths
from heart attacks and accidents on the Monday
Figure 3.12 Lark and owl
after the beginning of daylight savings time. Rus-
sian researchers also claim their country had an
About 40 percent of humans are larks, about enormous increase in heart attacks and suicide
30 percent are night owls, and the remaining 30 per- rates on that day, and for that reason, Russia and
cent fall in the middle. This genetic variation within many countries are abandoning the daylight sav-
our species is quite inconvenient in our modern ings time shift. But if it causes so much harm, why
world, which operates mostly around a nine-to- and where did it begin?
five workday. It is especially difficult for the night This shifting of the clock time—in the US, set-
owls, who have to start engaging their brain sev- ting it ahead by an hour in March and then return-
eral hours before they are metabolically ready every ing to standard time in November—originated in
morning. It is unfortunate that our society does not
accommodate different chronotypes, especially
considering the health consequences (increased
heart disease, diabetes, brain disorders) and acci-
Your Next
dents associated with disrupting a person’s natural
Actions for
circadian rhythm. Considering all this may make
Justice
you wonder why the different chronotypes exist. Yet If your community
looking to our tribal ancestors, these different chro- still practices day-
notypes make perfect evolutionary sense. If it is time light savings time, consider writing your
for the tribe members to sleep, the safer outcome in congressperson or a letter to the editor
terms of avoiding attack during sleep would be to in your local newspaper and start a con-
have a few members awake late at night and a few versation to make health the priority and
alert and functioning before dawn. Thus the larks discard daylight savings time.
and owls were the revered sentinels (figure 3.13).
 Circadian Rhythm: Derailing the Circadian Rhythm • 57

Figure 3.13 Storytelling

different periods of history, and independently in the morning shift from 1:00 a.m. to 9:00 a.m. Shift
many countries for varied reasons. For example, a work is associated with devastating health problems
New Zealand entomologist in the late 1800s wanted such as increased rates of cardiovascular disorders,
more evening hours to find insects, and the Germans depression, diabetes, and cancer. The World Health
during World War I hoped it would help their war Organization has listed shift work as a probable car-
effort. Currently, only a little more than a third of cinogen, as it is associated with cancer. They state
countries in the world engage in this practice. Many this is due to the health damage that comes with
nations—based on science and as a reflection of disrupting the circadian rhythm.
their value of health, safety, and productivity—are One of the recommendations to help shift work-
making the move to ditch the practice of shifting ers is to eliminate the weekly rotation between
the clock. shifts so the body does not have to experience the
Regardless of time zone, many people have to equivalent of traveling through eight time zones
live by a different clock because of their work hours. every week and never settling on any circadian
While some have the luxury of a 9:00 a.m. to 5:00 p.m. rhythm. Science indicates that if rotation is nec-
workday, a shift worker may have to work through essary, the shifts should be rotated clockwise: from
the middle of the night (figure 3.14). More challeng- day shift, to night shift, to morning shift. This
ing still, some shift workers have weekly rotations in movement, while not at the same magnitude, is at
their shifts, from daytime to nights to mornings. A least in the same direction as our internal circadian
night shift might be from 5:00 p.m. to 1:00 a.m., with rhythm, which is fifteen minutes longer each day,
 58 • Circadian Rhythm: Derailing the Circadian Rhythm

Figure 3.14 Shift workers

making us naturally want to go to bed and wake up reset our internal clock. Studies have shown that
later each day. The other advice is to rotate every if an animal is not getting enough food, light takes
three weeks, not every week. Protecting the eyes a back seat as the strongest zeitgeber. The driving
from sunlight and blue light with tinted glasses in factor for circadian rhythm becomes all about the
the two hours before sleep is also helpful for shift best time to get food. See chapter 6 for approaches
workers, especially those driving through bright to minimize jet lag.
sunlight as they head home for their much-needed
sleep.
The time zone change experienced with air-
line travel has some difficulties in common with
shift work (figure 3.15). Scientists have shown how
jet lag can cause digestion problems, menstrual
cycle irregularities, feelings of depression, and
foggy thinking. Left to its own, the SCN adjusts to
a new time zone by only an hour a day, so thank-
fully, there are several effective jet lag strategies.
One of the most surprising protocols is fasting to Figure 3.15 Flying into a different time zone
 Circadian Rhythm: Polyphasic versus Biphasic • 59

thirty minutes for caffeine to kick in, but it can still

be in the system eight to ten hours later.

Polyphasic versus Biphasic

If there is a group of people with the resources and
will to hack the circadian rhythm and reduce the
hours of sleep needed, it would be the National
Aeronautics and Space Administration (NASA).
Every hour an astronaut is in space is expensive,
and every hour they are sleeping is an hour they
could be working (figure 3.17). Yet even NASA sci-
entists have not figured out a way to get around
the fact that most of us need around eight hours
of sleep and a ten-minute nap every day. This is
biphasic sleeping: two sleep periods every twenty-
four hours. Solo sailors are also interested in find-
ing a way to sleep less and still perform optimally,
as they may be at sea for days and must keep their
Figure 3.16 Caffeine impacts the circadian rhythm
sailboat safe and on course.
Consequently, Claudio Stampi, a sleep specialist
Jet lag and demanding work and school sched-
and expert round-the-world sailor, was a leader in
ules motivate many people to turn to caffeine in
the development of polyphasic sleeping for sailors,
an attempt to forestall the circadian rhythm (fig-
athletes, and others in extreme situations, includ-
ure 3.16). But we pay for that short-term boost. The
ing outer space. One form of polyphasic sleeping is
adenosine activity that creates sleep pressure gets
taking a thirty-minute nap every four hours, for a
intercepted by caffeine, which blocks adenosine
total of three hours’ sleep in a twenty-four-hour
receptors in the brain, so they are not able to be
activated. Theobromine, a constituent of choco-
late, works in a similar manner to caffeine as it also Retrieval Practice
blocks adenosine receptors. Having the adenos- After studying the paragraph about
ine receptors blocked, whether it is via caffeine or caffeine and adenosine recep-
theobromine, creates a short-term illusion that we tors, go back to the beginning of
are not sleepy. However, adenosine is still building the chapter and review the role
up at its normal rate. Then, when the caffeine (or of adenosine triphosphate (ATP)
theobromine) is broken down and the adenosine breakdown in making you sleepy. Set aside the
receptors are available again, there is an extra high content and do not let yourself look at it. On
level of adenosine in the brain, and the adenos- a piece of paper or using your computer, create a
ine receptor activation is substantial, causing the rough sketch and explanation of how caffeine
typical crash experienced several hours after caf- works to keep you awake and why there is a crash
feine use. For some, the next step is another cup several hours later. Include adenosine receptors
of coffee, continuing the cycle—which will have in your sketch. Then open up the book and your
disastrous effects on sleep that night. Depending notes and make corrections to your drawing and
on factors such as age and genetics, caffeine is explanation.
metabolized at different rates: it may take around
 60 • Circadian Rhythm: Polyphasic versus Biphasic

bygone sleeping pattern. In the past, this theory

purports, the schedule was to sleep several hours
at night, awaken at midnight for a couple of hours,
and return to sleep for several more hours. Some
reported that this is the biphasic sleeping pattern
we are all meant to follow. This practice seemed
to originate around the 1700s among a group of
Western Europeans: after sleeping several hours,
they would wake up for singing, sex, praying, or
storytelling, then finish the rest of their slumber
until morning.
While it made popular headlines, evidence indi-
cates this was an isolated practice and that there is
no biological justification for it. The jury is in: based
on the scientific examination of human circadian
rhythm over the ages and in current times, we
have indeed evolved to be biphasic sleepers—that
is, sleeping around eight hours each night with a
ten-to-twenty-minute nap in the afternoon.

Figure 3.17 Sleeping in space

period (figure 3.18). However, even Stampi himself,

a self-proclaimed biphasic sleeper, is clear that
polyphasic sleeping is only for extreme events and
is an unhealthy practice long-term.
Despite this, the concept of gaining additional
waking hours each day became irresistible for lay-
people, who see it as a way to potentially add years
of awake time to a person’s life. Based on sleep debt
research, however, the health damage caused by
this sleep schedule would likely actually take sev-
eral years off a person’s life and lessen the quality
of their living years by diminishing cognitive func-
Figure 3.18 Sometimes polyphasic sleeping is referred
tion, lowering mood, reducing physical abilities, to as the uberman schedule. This figure compares poly-
and more. In spite of the contradiction, the practice phasic to biphasic sleep. The circle represents time in the
has taken off and gained a following. It is an unfor- 24-hour day, so the small dark blue sectors in the uber-
man (polyphasic) schedule are the six thirty-minute
tunate misinterpretation of Stampi’s research.
naps. On the biphasic image, the large dark blue sector
Another probable misinterpretation related to is eight hours of nighttime sleep and the small sector is
circadian rhythm research is regarding news of a the twenty minute afternoon nap.
 4
Animals

Student Learning Since it is not possible to hook up a bug to EEG,

EOG, and EMG to verify sleep physiologically,
Objectives for many life-forms, we must rely on this more
After you read this chapter, you will be able to behavioral definition of sleep—for example, a ste-
• compare and contrast sleep in various reotypical resting posture combined with reduced
insects, fish, and mammals response to the external environment. And let’s
• explain how understanding unique sleep be sure to add that sleep is a reversible state—one
characteristics from animals provides of the hallmarks of sleep, thank goodness. In the
insight into human sleep absence of polysomnography, an additional fac-
• discuss the significance of sleep’s tor to add to the equation for verifying sleep is
persistence throughout evolution to note the strong drive the organism exhibits to
return to that “sleeping” state when deprived of it.
But how would you know a sleep-deprived insect
is trying harder to sleep? Scientists record the
Introduction baseline level of stimulation required to awaken
Animals, such as lions, that eat many pounds of the sleeping creature when it is left to its normal
meat in a single meal can spend fifteen hours a day rhythm for a few days. Then the creature is kept
sleeping. Compare this to plant-eating animals, like awake during what would be its sleeping time. In
giraffes, which sleep an hour or less each day (fig- this sleep-deprived condition, more intense stim-
ure 4.1). If you were to make a hasty survey, it appears ulation is required to rouse the creature from sleep.
predators sleep more than other animals. However, Imagine your roommate awakening you by softly
there are exceptions to that generalization and others tapping you on the arm after you’ve had several
like it (such as that smaller animals sleep less than nights of full and comfortable sleep. Compare that
larger ones). There are a multitude of theories about to the jab required if you have at long last dozed off
the sleep duration differences between animals, but after pulling an all-nighter. This exemplifies one
currently, there is no clear front-runner. Even within aspect of sleep rebound: sleeping more deeply after
groups of animals that are similar genetically, there being kept awake too long. The other aspect is fall-
are sometimes more pronounced sleep duration dif- ing asleep during what are normally waking hours.
ferences than between vastly dissimilar animals. We In lieu of physiological measurements to verify
do know all creatures studied so far have a period of that an organism is sleeping, the behavioral defini-
something similar to sleep. Even unicellular organ- tion proves helpful. Upon observation of behaviors,
isms have stretches of time, linked to the earth’s even insects will provide additional clues—beyond
light-dark cycle, when they barely move and have a just a resting posture—to let us know they are
decreased reaction to stimuli. sleeping.
 62 • Animals: Insects

Figure 4.1 Delicious

Insects do not get sufficient sleep they have poor mem-

ory, have reduced learning function, and die ear-
Like humans, fire ants have different stages of
lier. They have also been used to demonstrate the
sleep. They start with their mouths open and
reduction in sleep associated with starvation. If a
antennae retracted or drooping (figure 4.2). Then
creature is not getting enough calories, the body,
the antennae begin quivering as the fire ant moves
into rapid antennal movement (RAM) sleep. Might much to its detriment, will reduce the time spent
they be dreaming? Could RAM sleep be an equiva- sleeping to instead seek food. One of the most
lent to REM sleep—even though much research compelling sleep-related findings in this research
suggests that insects have no equivalent to REM? was the discovery of a gene that controls circa-
At this point, it remains an enigma, motivating dian rhythm (see chapter 3). These scientists were
further investigations. awarded the 2017 Nobel Prize in Physiology or
Another insect, the fruit fly, often examined Medicine for their work.*
when there is a need for deciphering genetics, is a
favorite for sleep research. Fruit flies have many
Fish
genetic and physiological similarities to humans,
including getting a buzz from caffeine that keeps For ages, scientists believed that sharks do not sleep
drowsy flies awake. As with humans, if fruit flies because their eyes are open when they settle into

* “The 2017 Nobel Prize in Physiology or Medicine—Press Release,” Nobel Prize, accessed May 28, 2021, https://www.nobelprize
.org/prizes/medicine/2017/press-release/.
 Animals: Reptiles • 63

fighting or attacking. Great white sharks, which

do not have eyelids, have to roll their eyes back to
protect their eyes when attacking. This Discov-
ery Channel video captured a great white shark
sleeping.* You may have heard that some sharks
need to move while sleeping to get oxygen across
their gills, and this is true. But other sharks have
spiracles that draw in water and move it over their
gills so they do not need to move during sleep.

Figure 4.2 Red ant

Reptiles
As late as 2016, many believed that reptiles have
their quiet resting posture. Upon further investiga- NREM sleep but not REM sleep. However, when
tion, it became apparent that sharks were sleep- researchers at the Max Planck Institute for Brain
ing, but they do not close their eyelids during sleep Research in Frankfurt began to study the Austra-
(figure 4.3). Some sharks have a clear membrane lian dragon—a type of lizard that is a popular pet
covering their eyes, and others have eyelids par- in Germany—a surprising story emerged (fig-
tially covering them. The purpose of shark eyelids ure 4.4). The scientists set out to study visually
is not sleep related; it is to protect their eyes when guided behaviors and were continuously recording

* Discovery, “Great White Naps for First Time on Camera,” YouTube video, 2:33, June 28, 2016, https://www.youtube.com/watch
?v=B7ePdi1McMo.

Figure 4.3 Shark

 64 • Animals: Reptiles

activity—and also REM brain activity, combined

with tiny twitches in the eyelids during the REM
phases. Part of the significance of this finding is
related to how REM sleep is also found in birds
and mammals, creatures that evolved separately
and much later than reptiles. Until this Australian
dragon research, the conventional wisdom was
that evolutionary pressure along two isolated evo-
lutionary pathways (those of birds and mammals)
resulted in the emergence of REM sleep—people
thought REM sleep did not exist before birds and
mammals. Now it is clear that REM sleep existed
much earlier in the evolutionary line and was likely
handed down to both birds and mammals.
REM sleep in other reptiles remains to be exam-
Figure 4.4 Australian dragon ined, but reptilian behavioral sleep patterns have
been observed for ages. The beloved honu (green
the lizards’ brain activity using electrodes. They did sea turtle of Hawai‘i) sleeps in the ocean for sev-
this for several days at a time, also using infrared eral hours, usually close to the surface, holding
cameras to record nighttime behavior. Although its breath (figure 4.5). Near the shore, they doze
sleep was not the focus of the study, they found several feet under water, cozy under the edge of
the lizards had the typical NREM slow-wave sleep a coral reef.

Figure 4.5 Honu

 Animals: Birds • 65

It can be difficult to determine if snakes are just for their own self-preservation but also that
sleeping or simply not moving. Since the thin of their community. Sleeping in a row, sentinels
membrane covering their eyes is clear, they appear on each end of the row keep one eye open, sleep-
to sleep with their eyes open. ing with only one hemisphere of their brain. The
Some geckos do actually sleep with their eyes birds in between the sentinels enjoy a completely
open, but they constrict their pupils down to pro- restful night of shut-eye, with both hemispheres
tect the retina. Other geckos are fortunate enough sleeping at once (figure 4.6). At either end, each
to have eyelids they close, just as humans do when sentinel bird’s open eye faces out, so after a period
sleeping. of sleep in this position, the bird arises and turns
around to face the opposite direction, opening the
closed eye, and letting the previously active brain
Birds hemisphere and eye get some sleep. Even though
Birds have evolved to sleep with one hemisphere they are processing information with only half of
of their brain at a time, keeping an eye on things their brain, it takes less than a fifth of a second
while they snooze. This leaves the awake half of the for the guard birds to react to a predator. Although
brain alert and able to process information coming REM sleep is normal for birds, it seems both hemi-
from its associated eye, which remains open during spheres must be engaged in sleeping to generate
sleep. Ducks and many other birds use this skill not REM. Consequently, these vigilant guardians on
the end of the row are only able to get NREM sleep
when on duty.
Humans have a rather subtle version of sleep-
ing with one hemisphere for the sake of vigilance.
Have you ever noticed you sleep a little lighter on
the first night staying over at a friend or family
member’s home? And then if you stay with them
for a few more nights, you notice your sleep feels
more satisfying. During NREM in new surround-
ings, half of our brain will have a lighter version
of deep sleep; the other half will have its normal
restorative depth. This allows us to keep watch,
ever so slightly, in our less-than-familiar setting
until we have settled in for a few more nights and
feel entirely comfortable.
Birds have another fascinating sleep-related
adaptation. Due to their need to migrate thousands
of miles over the ocean, they have evolved to safely
fly nonstop for hours and hours, seemingly without
sleep . . . or are they sleeping while flying? Yes, they
are, and it is a unique sleep pattern. Frigate birds
(‘iwa in Hawaiian) fly for months straight and so
will sleep about ten seconds at once, in flight, get-
ting less than half an hour of sleep each day.
Some birds, such as the white-crowned spar-
row, have even attracted attention from groups
Figure 4.6 Safe sleeping with sentinels such as the US Department of Defense. This sparrow
 66 • Animals: Mammals

‘Ōlelo Hawai‘i
(Language of Hawai‘i)
‘Iwa is Hawaiian for “frigate
bird” (figure 4.7).

can stay awake for two weeks at a time during its

migratory period and apparently not suffer the
usual deleterious consequences of sleep depriva-
tion. During these phases, the bird also remains
capable of proficiently responding to stimuli. The Figure 4.7 Frigate bird
US military, with its history of pressuring troops to
use various forms of stimulants such as amphet- away while snoozing. Occasionally, they even hold
amines (with deadly consequences), is highly hands (figure 4.10). In open grassy areas, cows,
motivated to determine a way to keep people such horses, zebras, and elephants can sleep standing
as pilots awake for long stretches at a time without up, able to quickly flee if attacked. They have a
not compromising their judgment or damaging “stay apparatus” that allows them to essentially
their health. At this point, the science suggests it is lock their legs, minimizing muscular effort to
not possible. Let’s hope for the sake of the troops, remain standing. At times, these big mammals
their families, and the world community that there also lie down to sleep in order to complete their
are also researchers actively investigating revolu- sleep architecture.
tionary and innovative solutions to minimize the Noticing the range of adaptations and behav-
need to put people in harm’s way. iors that make it possible for animals to sleep and
survive, we see that sleep has persisted even in
the face of environments where it seems it would
Mammals
have been simpler to just eliminate it from the
Imagine swimming through the ocean with half mix. As Alan Rechtschaffen, a sleep science trail-
of your brain asleep, or catching z’s while dan- blazer, has said, “If sleep does not serve an abso-
gling like a ripe mango from a tree (figures 4.8 lutely vital function, then it is the biggest mistake
and 4.9). The unihemispheric sleep of dolphins the evolutionary process has ever made.”* Then
allows them to swim and communicate—during
sleep—with other dolphins. Up in the trees, bats,
with their unique wing structure, are unable to
create the rapid vertical takeoff mastered by birds.
The best way for a sleeping bat to escape a hungry
raccoon lumbering toward its roost is for the bat
to drop from the tree and take flight midair. In the
sea, dozens of sea otters come together and wrap
themselves in seaweed, creating a sea otter raft
for safety in numbers and to keep from drifting

* E. Mignot, “Why We Sleep: The Temporal Organization of

Recovery,” PLoS Biology 6, no. 4 (April 2008), https://doi.org/
10.1371/journal.pbio.0060106. Figure 4.8 Dolphins
 Animals: Mammals • 67

Ready to Move On?

Before moving on, establish
that you have a clear under-
standing of Rechtschaffen’s
statement, “If sleep does not serve an abso-
lutely vital function, then it is the biggest
mistake the evolutionary process has ever
made.” In your own words, explain what
he meant.

Figure 4.9 Bat

blush, it seems it would be easier to evolve to not
sleep than to evolve the mechanisms necessary
how can we resist the question, “Why is sleep so
to sleep while swimming. In other words, sleep
vital?” Let’s further investigate animal sleep and
is indispensable!
get some answers.
Getting back to unihemispheric sleep in aquatic
Although they live and sleep in the water,
mammals, there are exceptions: seals have bihemi-
whales, seals, and dolphins are mammals and so
spheric sleep underwater (they hold their breath)
must breathe in the air. If they fell fully asleep
and sperm whales sleep with both hemispheres
underwater, they would drown, so like some
too, seemingly dangling in the water, tail down,
birds, only half of their brain sleeps at a time.
until they awaken to swim to the surface to take a
When one hemisphere is sleeping, the other
breath (figure 4.11).
hemisphere guides the animal to the surface and
Dolphins and some whales do not show obvi-
activates the body to take a breath. The visual sys-
ous signs of REM sleep, but scientists speculate
tem of the awake hemisphere is vigilant for danger
that they may experience transient REM sleep or
and stays connected to other animals in its group,
REM brain activity in deeper structures than the
such as companions or offspring. These elaborate
cortex. This motivation to not rule out dolphin and
evolutionary adaptations suggest that sleep must
whale REM sleep is partially due to observed mus-
provide a crucial function, since sleep does not
cle twitching, penile erections, and eyelid move-
make it to the bargaining table when evolutionary
ments during dolphin sleep. These behaviors are
pressure looks for behaviors to remove. At first
associated with REM sleep in land mammals but
also occur during waking states, so REM sleep in
dolphins remains an area of active research. Dol-
phins are so highly evolved that maybe we will see
they have a unique form for REM that provides
additional survival benefits beyond those given to
us humans during REM sleep.
Fur seals do clearly have REM sleep, but they
add a unique variation to its predictability. On land,
the fur seal sleeps with both hemispheres at once
and goes through REM and NREM stages, similar
to most mammals (figure 4.12). However, when a
Figure 4.10 Sea otters fur seal sleeps in the water, its sleep is similar to
 68 • Animals: Mammals

Figure 4.11 Sleeping sperm whales

a dolphin’s: it sleeps with one hemisphere at a in the middle of deep NREM sleep, when our brains
time, and NREM is the only obvious sleep stage. are cool and sluggish.
Because fur seals spend weeks at a time in the sea, If REM sleep did not provide an essential benefit,
they go for long stretches without REM. But why then it seems the fur seal would continue its uni-
would a seal have two different patterns of sleep, hemispheric NREM sleep when snoozing on land.
depending on whether or not it was sleeping in However, it has evolved to incorporate REM sleep
the water? whenever it returns to its terrestrial home. With the
A current theory about REM is it increases brain
metabolism and warms the brain and brainstem,
balancing out the lower metabolic rate and brain
temperature of NREM. When fur seals, dolphins,
and whales sleep in the water, one hemisphere at
a time, and exclusively in NREM, the theory is they
would not need REM to warm up the brain, since
half of the brain is always awake and warm. Then
when the fur seal is sleeping on land, it reverts to
the typical land mammal pattern of bilateral NREM
interspersed with REM. We humans feel much more
alert if we wake up shortly after or even during an
REM period, as opposed to when our alarms go off Figure 4.12 Hawaiian monk seal
 Animals: Mammals • 69

Your Next Actions for Justice

Did you know that some organizations conduct sonar and explosives testing
in identified habitats of whales, dolphins, and porpoises, furthering the
real possibility of their extinction?* In addition to disrupting their sleep,
this testing causes grave harm, even death, to ocean creatures. Whales,
dolphins, and porpoises are so affected that in Guam, eight senators created a resolution, with
strong backing from the community, to stop such testing in that region. Of course, the people
of Guam fought for this because they care about the animals, but they also did it because Guam
is an island nation, where their cultural identity, social fabric, and economy are linked to the
health of their region’s sea life. Your next step for action is to investigate sonar and/or explosives
testing in the ocean. Find out where it is happening, in what parts of the world, and more details
about the communities affected and the environmental impact. Based on your research, select
the information that is most meaningful to you and post on social media (or send an email to
several friends if you don’t use social media) to share a brief and factually accurate synopsis of
your findings.

* Ocean Conservation Research: Sound Science Serving the Sea, last modified May 2021, https://ocr.org/.

myriad REM sleep–associated benefits—including REM, the platypus has rapid eye movements and
emotional healing, cardiovascular system regula- twitches its bill. Its REM EEG is similar in many
tion, and more—it is tempting to believe REM sleep ways to newborn placental mammals, which have
would be incorporated into a creature’s sleep cycle high rates of REM too. The brainstem EEG of a
if at all possible. platypus shows that REM occurs at the same time
Let’s look way back in time to compare varia- as cerebrocortical slow-wave sleep, explaining
tions in mammalian sleep. During the early stages why early investigators may have miscategorized
of mammalian evolution, monotremes branched its sleep pattern.
off from placentals and marsupials. Monotremes
(e.g., platypuses) are egg-laying mammals. This
is in contrast to placentals (e.g., humans), which
carry the fetus in the uterus until a relatively late
developmental stage, and marsupials (e.g., kan-
garoos), which give birth before the animal is
completely developed, so after birth, it is usu-
ally carried in a pouch on the mother’s body
(figure 4.13). Although for decades, scientists
believed monotremes do not experience REM
sleep, there are now studies showing that platy-
puses not only have REM sleep but have a higher
rate of it than placentals or marsupials.* During

* J. M. Siegel et al., “Monotremes and the Evolution of Rapid

Eye Movement Sleep,” Philosophical Transactions of the Royal
Society B: Biological Sciences 353, no. 1372 (July 1998): 1147–57, Figure 4.13 Monotreme, placental, and marsupial
https://doi.org/10.1098/rstb.1998.0272. mammals
 70 • Animals: Hibernators

Retrieval Practice
Look up the meaning of adaptation in the context of organisms. When you are clear on its
meaning, start at the beginning of the chapter and skim the content, making note of all
the adaptations and behaviors animals make in order to sleep and/or survive while sleep-
ing. Then set aside the content and your notes and do not let yourself look at that material.
Relying only on your memory, make a list of all the adaptations and behaviors you noted.
After you are done honoring that you were able to retrieve some of the content from your mind, open
the book and your notes and make additions and corrections to your retrieval practice list. Remember to
have a sense of humor and be kind to yourself if you made mistakes or could not recall some of the facts.
The brain learns better with kind criticism than with harsh words. This is also an opportunity to see if the
way you are reading and taking notes is working for you. If it is not, make a change to how you approach
studying the textbook. It may be helpful to stop more often while reading and do tiny retrieval practices
like this one. It will save you time in the long run.

Hibernators their metabolism and activate their brain. When

they are hibernating, their EEG is practically a
A common myth is that hibernation, which can
flat line, as though they were not alive. Remem-
last a few hours or as long as several months, is
ber learning about dendrites in chapter 2? During
the same as sleep. However, although hibernation
has evolved from sleep, there are fundamental the first day of hibernation, ground squirrels lose
differences between the two. In fact, some ani- about one-fourth of their dendrites. Then, within
mals will bring themselves out of deep hiberna- hours of coming out of hibernation, the dendrites
tion in order to get sleep and then return back to are restored. Other physiological functions, such
hibernation after a satisfying snooze. Also, sleep as urine production, come to almost a halt during
is easily and rapidly awoken from, but it takes an hibernation as well. But after rousing from their
hour (or more, depending on the animal) to rouse week of hibernation, during that twenty-four-
from hibernation. And what about the function hour period at their normal body temperature,
of hibernation compared to sleep? A fundamen- they eat, pass waste, and sleep before returning to
tal purpose of hibernation is to save energy. If another week of hibernation.
sleep and hibernation had energy conservation as
a common goal, it would not make sense to expend
energy to warm up the body during hibernation in
order to create conditions necessary for true sleep.
Yet some animals, even in frosty conditions, do
exactly that.
Ground squirrel body temperature can remain
close to zero degrees Celsius, the temperature at
which water freezes, during hibernation, which
could last the entire winter (figure 4.14). How-
ever, once a week, for around twenty-four hours,
they bring themselves out of hibernation. It takes
a while, and a lot of energy, for them to speed up Figure 4.14 Ground squirrel
 Animals: Hibernators • 71

Figure 4.15 Bear

If I say “hibernating animal,” what creature body temperature allows bears to generate NREM
comes to your mind? If it is a bear, you are in good and REM sleep during hibernation. They also stay
company, as this is the typical response (fig- in their state of torpor for the entire winter, not
ure 4.15). You may find it surprising that some sci- bothering to invest energy in the weekly rousing
entists argue that bears are not true hibernators; practiced by the ground squirrel. Lastly—and this
others suggest that theirs is just a different form of is a significant difference from the ground squir-
hibernation. A bear’s body temperature will drop rel, as intrepid hikers will tell you—a hibernating
only a few degrees, even when outside tempera- bear can be roused quickly and easily.
tures are below freezing. This closer-to-normal
 5
Dreams

Student Learning REM, but during REM sleep, our dreams become
more intense in their content and often bizarre
Objectives in nature. Conversely, if awakened from NREM
After you read this chapter, you will be able to dreams, many report that it feels as though they
• discuss theories about several different were simply thinking about something rather
dream functions, including emotional boring. We know dreams occur throughout the
healing, memory consolidation, problem- night, but in this chapter, dreaming refers, unless
solving, and emotional intelligence
development
• explain the role of dreaming in
posttraumatic stress disorder recovery
• describe how dreams are created
• compare and contrast several theories
about dream interpretation
• discuss dream significance from the
perspective of different cultures
• teach someone how to lucid dream
• provide instruction for conducting a dream
group

Introduction
In the early moments of trying to fall asleep, we
may experience a stunning hallucination that
startles us back to reality, leaving us to wonder,
“What was that?!” It is disorienting because we
feel we were not yet sleeping. These hypnago-
gic hallucinations occur around sleep onset (fig-
ure 5.1). They are a type of dream—if you define
dreaming as something going through your mind
while you are asleep—but some people refer to
hypnagogic hallucinations as “sleep think-
ing.” We dream in all stages of sleep, NREM and Figure 5.1 Under the covers
 74 • Dreams: Emotional Healing

stated otherwise, to the dreaming state associated

with REM sleep. Let’s begin with a discussion of
the importance of dreams to our mental well-
being, because in the words of Nobel laureate Elias
Canetti, “All things one has forgotten scream for
help in dreams.”*

Emotional Healing
Dreams help us cope with, and better understand,
our emotions. During the day, emotional events
happen, but we rarely pause for reflection because
we are pressed to continue with the business of the
moment. When we are dreaming, it is an opportu-
nity to take the emotions of the day and relate them
to memories—even those from long ago—to see Figure 5.2 We’ve all been there
if we can make sense of the situation and be bet-
ter prepared for the next time something similar emotional dreams, we can replay events without
occurs. the stress response triggered by norepinephrine.
Imagine an emotional event during the day, Matthew Walker, a sleep scientist at the Univer-
such as a group activity in class in which you felt sity of California, Berkeley, has led brain imaging
socially uneasy, like you did not fit in (figure 5.2). research in this area to show how the brain takes
Maybe you said something that was poorly received advantage of this zero-norepinephrine condition
or were given a disapproving look by one of your to relate clear recollections of crucial events to pre-
classmates, but you had to continue with the work vious memories without engaging the flight-or-
at hand. You may or may not have forgotten about fight brain circuits that would distract us from
it by the time you went to bed. Either way, that calm introspection. The result is that we are able to
night, your dream might have an emotional theme shed the emotionally painful layer of the memory
of social rejection, but in a scene involving people and still retain details of the situation to help us
you haven’t seen in years rather than your current be better prepared to face another day . . . or that
classmates. Through dreams, your brain can create judgy classmate!
a mash-up of current and previous experiences to Dreaming about emotional events brings us to
optimize your future behavior—the perfect harm- a place where we are more comfortable with the
free dress rehearsal. situation. Psychologist Rosalind Cartwright, also
While our dreams are synthesizing such rela- a world-renowned sleep specialist and expert on
tionships between recent emotions and distant dreaming, has published extensive research show-
memories, the brain experiences its lowest levels ing the benefit of dreaming for emotional recovery.
of stress hormones over the course of twenty-four Dreams mentally evolve us to a point where our
hours. One of these hormones, norepinephrine daily activities, as well as our sleep, are less dis-
(also called noradrenaline), is present in the turbed by feelings associated with challenging life
brain at various levels throughout the day and events. She says a part of the purpose of dreaming
night—except during REM sleep. During our vivid is so that “negative mood [can be] down-regulated

* Deirdre Barrett, ed., Trauma and Dreams (Cambridge, MA: Harvard University Press, 2001), 282.
 Dreams: Emotional Healing • 75

Figure 5.3 Staying together

overnight.”* Although, she is quick to clarify that passed, they may have posttraumatic stress disorder
recovery from difficult life events will take many (PTSD; figure 5.4). People with PTSD have increased
nights, maybe months, of dreaming about them. levels of norepinephrine in their brains during REM
Cartwright has done brilliant research and clini- sleep. This is the opposite of the norepinephrine-
cal work with patients experiencing despair at the free condition responsible for emotional healing
time of an upsetting life event, such as a breakup during REM dreams, which is experienced by those
with a partner (figure 5.3). She found people who without PTSD. For folks suffering from PTSD, the
dreamt of the event, especially around the time of presence of norepinephrine during REM sleep dis-
its occurrence, experience a significant ameliora- rupts the ability for dreams to reduce the emotional
tion of depression compared to those who did not intensity associated with disturbing events. But
dream of the event (even if they did still dream of because the mind still wants to work out the prob-
other things). lem while dreaming, it will repeatedly attempt to do
This progression to recovery has a more com- so with a dream, sometimes every night, resulting
plicated path for individuals faced with trauma and in recurring nightmares—one of the most common
nightmares. If someone experiences a frightening symptoms of PTSD.
or dangerous event, and feelings of being scared or Imagery rehearsal therapy (IRT) has been used
stressed remain strong long after the danger has successfully to help people with PTSD work with a

* R. D. Cartwright et al., “REM Latency and the Recovery from Depression: Getting Over Divorce,” American Journal of Psychiatry
148, no. 11 (November 1991): 1530–35, https://doi.org/10.1176/ajp.148.11.1530.
 76 • Dreams: Memory and Learning

about the benefit of working with dreams as a part

of the recovery process for PTSD. She explains that
dreams provide a “barometer” of a person’s mental
state, delivering insight into a patient’s progress.*

Memory and Learning

Through dreams, our brains create connections
between recent experiences and long-term memo-
ries. This equips us with new perspectives, allow-
ing us to better respond to similar situations in the
future. Our sense of self or identity also changes
through dreams as we see our role in a recent situa-
tion through the lens of a memory from our distant
past. Procedural memories—those for things like
playing a song on the guitar or making your favor-
ite cookies—are also processed and stored through
dreaming. When we are learning a new procedure,
let’s say a dance routine, we will notice the first time
we try it after a night of dreaming, we will do much
better than on the previous day. NREM and REM
dreams both play a role in memory formation, but
there is a difference. NREM dreams serve more to
Figure 5.4 Soldier strengthen memories, and REM dreams restructure
them, marrying fresh experiences to earlier ones.
therapist to transform nightmares into less disturb- Taking a deep look at how dream content has
ing dreams. The concept is to create a more com- an impact on learning and memory, sleep science
fortable version of the nightmare and retain enough experts Erin Wamsley and Robert Stickgold studied
nightmare details so the mind will slip into this new navigation in a virtual maze (figures 5.6a and 5.6b).
version. For example, if a person has a nightmare Human participants trained on the virtual maze and
of being attacked by a shark, the new version will then were allowed to sleep overnight. In prior ani-
still have water splashing, a fin in the water, and the mal studies on the subject, researchers had already
feeling of a strong bump against the body of an ani-
mal. However, in this new version, the splashing is
from a dolphin playing nearby, not a shark thrash-
ing; the fin is a dolphin fin, not a shark fin; and the
bump to the body is gentle, from the friendly dol-
phin (figure 5.5). People write out the new version
of the dream, create an art piece depicting it, and tell
the new dream as a story to another person. They
meditate on the new dream before sleep to train the
mind to shift over to this new set of details. Harvard
psychologist Deirdre Barrett has written extensively

* Barrett, Trauma and Dreams, 282. Figure 5.5 Transforming the nightmare
 Dreams: Memory and Learning • 77

Your Next Actions for Justice

Think of someone you know who may have nightmares and ask them if you
can share what you know about imagery rehearsal therapy (IRT). Since you are
a layperson, skip this next step if the person is experiencing trauma, but if not,
find out if they would like to share their nightmare with you so you can guide
them, in your role as a student, through your understanding of IRT. If they have experienced trauma
or if the nightmares are significant, you may suggest that they instead ask their mental health-care
practitioner for help with IRT, since your advising them would be beyond the scope of your experience.
If in these conversations you meet someone with suicidal feelings, contact the US National Suicide
Prevention Lifeline* 1-800-273-8255. Another way to help would be if you know of a veteran or
someone who works with veterans, in which case you could tell them what you know about IRT and
suggest they consider looking further into it to help their clients and/or fellow veterans.

* “National Suicide Prevention Lifeline,” accessed on December 3, 2021, https://suicidepreventionlifeline.org/.

shown that the animals’ brain firing patterns during the result being improved outcomes in our next wak-
sleep closely matched the patterns seen when they ing encounter with similar challenges.†
were learning a maze, but how could we know what
the animals were dreaming about? Previous studies
on animals and humans also provided evidence of
improved performance being associated with sleep-
ing after attempting a task. The novelty of Wamsley
and Stickgold’s research was in asking participants
about their dreams’ content during the night and
establishing the clear relationship between maze-
themed content in dreams and success in navigating
the maze the next morning. They also found that the
participants who did not perform well during practice
sessions with the maze were more likely to see the
maze in their dreams that night.* If something is chal- Figure 5.6a Virtual reality goggles
lenging for us, our brain knows we will be more likely
to overcome the challenge if we dream about it. This
fits well with Antti Revonsuo’s “threat simulation
theory,” which posits that dreams help us develop
better skills to behave successfully in the midst of
difficult situations. He states that through dreams,
we are able to rehearse threatening scenarios, with

* Erin J. Wamsley and Robert Stickgold, “Memory, Sleep, and

Dreaming: Experiencing Consolidation,” Sleep Medicine Clinics
6, no. 1 (March 2011): 97–108, https://doi.org/10.1016/j.jsmc
.2010.12.008.
† Antti Revonsuo and Katja Valli, “Dreaming and Conscious-
ness: Testing the Threat Simulation Theory of the Function of
Dreaming,” Psyche 6 (October 2000), https://www.researchgate Figure 5.6b Maze
 78 • Dreams: Problem Solving and Creativity

Knowing sleep has such a powerful influence

on storing memories, University of California, Los
Angeles, neuroscientist Gina Poe proposed a solu-
tion to help people with PTSD. The background for
her theory is work from an assortment of scientists
studying the relationship between sleep/dreams
and memory. When trying to learn something, one
way to increase memory capacity and accuracy
is to sleep, and thus dream, shortly after expo-
sure to the content. It turns out the timing of the
sleep matters for optimal memory creation: the
sooner, the better. This knowledge about timing
is used to schedule sleep for someone who has
experienced a traumatic event. Poe suggests it is
beneficial to hold off—for around eight hours after
the event—before sleeping.* Delaying sleep onset
diminishes the brain’s ability to store traumatic
event details, so the person is less likely to create
vivid and lasting memories that would haunt them.
With so much focus on dreams helping us cre-
ate memories, we could overlook a theory from the
1980s stating one of the functions of dreaming is
to “unlearn” information. Scientists Francis Crick
and Graeme Mitchison present a model of dreams Figure 5.7 Frankenstein
as a mechanism for sorting through information
in order to discard unnecessary memories from the the sewing machine, Friedrich Kekulé’s vision of
day. Consider when you are ready to leave campus: benzene ring structure, Keith Richards’ guitar riff
it is important you remember where you parked in Satisfaction, and more all are said to have come
your car or locked up your bike. The next day, it is from dreams (figure 5.7). Rather than take space
best if the parking information is not crowding up here to provide the details of these worn-out sto-
your memory space, but you still need to remember ries, you may Google the topics—and when you
how to get to class; dreams, in this theory, are a do, you will find Google itself was born in a dream!
way that parking information is culled while the There is one story worth telling here. It is about
route to class is maintained. an inspiring role model, Sarah Breedlove Walker
(a.k.a. Madam C. J. Walker), who was a civil rights
activist and philanthropist up through the early
Problem Solving and Creativity
1900s (figure 5.8). The wealth she built to provide
Stories of creative inspiration arriving through the financial resources to support herself and her
dreams are pervasive: Dmitri Mendeleev’s peri- philanthropy came in small part from a hair-loss
odic table of elements, Mary Shelley’s idea for remedy recipe that came to her in a dream. I say
Frankenstein, Elias Howe’s design of the needle for “small part” because most of her success is likely

.net/publication/232499090_Dreaming_and_consciousness_Testing_the_threat_simulation_theory_of_the_function_of
_dreaming.
* “Faculty: Gina Poe,” UCLA: Integrative Biology & Physiology, accessed June 6, 2021, https://www.ibp.ucla.edu/faculty/gina-poe/.
 Dreams: Problem Solving and Creativity • 79

of research that shows sleeping and dreaming on a

problem makes us more likely to gain insight into
a solution. Psychologist Ullrich Wagner and his
colleagues scheduled cognitive testing sessions
so that one group of participants would sleep in
between their first and second testing sessions,
while the other would not. The test consisted of
tiresome math problems. Rules were provided for
generating the solutions, but it was still a tedious
and prolonged experience. But there was a secret
shortcut that could be used if the participant had an
epiphany about an abstract rule. Such epiphanies,
in which the solution to a seemingly unsolvable
problem suddenly becomes clear, happen more
often if we dream about our problems. Wagner’s
team found that the people who slept between
their first and second attempts had significantly
more revelations that led them to the secret short-
cut than those without the opportunity to sleep.†
But what if the participants’ epiphanies about
the secret shortcut were due simply to the fact that
they’d slept and had nothing to do with the brain
restructuring memories of the test problems dur-
ing their dreams? To factor this in, they needed to
Figure 5.8 Madam C.J. Walker
do additional data collection on participants who
took the test only once. They divided participants
due to her fortitude. She started life as the daughter
who had not yet seen the test into two groups,
of freed slaves, living in financial poverty in Loui-
those who slept before the test and those who
siana, and spent years working as a single mother,
did not. There was no difference between the two
since her parents and husband died by the time
groups in terms of discovery of the hidden rule:
she was twenty. Then after a hard day of work as
the sleepers and nonsleepers had the same rate of
a washerwoman, she had a dream where a recipe
epiphanies upon taking the test for the first time.
came to her, including ingredients she ultimately
In other words, a participant had to have seen the
had shipped from Africa, for a product to help her
test problems before sleep (as in the protocol with
restore her hair, which had fallen out. She ulti- people taking the test twice) in order for the rate
mately became a successful businessperson and of epiphanies to increase (as they did when those
multimillionaire, dedicating herself to helping participants saw the problems again). Notice how
others. W. E. B. DuBois said of Walker, “It is given to the researchers included this essential part of the
few persons to transform a people in a generation. scientific method: seek to disprove your hypoth-
Yet this was done by the late Madam C. J. Walker.”* esis and look for alternate explanations, even if it
With scores of stories about dreams providing seems you have proven the hypothesis you were
creative solutions, it is no surprise there is a bounty seeking to prove.

* W. E. Burghardt Du Bois, “A Great Woman,” Crisis 18, no. 3 (July 1919): 131, https://modjourn.org/issue/bdr512386/.
† Ullrich Wagner et al., “Sleep Inspires Insight,” Nature 427, no. 6972 (January 2004): 352–55, https://doi.org/10.1038/nature02223.
 80 • Dreams: Emotional Intelligence

of others (figure 5.9). One aspect of this is being

Ready to Move On? able to distinguish different facial expressions,
such as for fear, anger, or joy. Without the benefit
Before moving on, consider
of time in our dream state, this ability drastically
this statement: “If you try
deteriorates to the point where not only do we lose
only to prove your hypothe-
the ability to tell the difference between a friendly
sis, you will.” Take a moment to think about
or angry expression on someone’s face but also
something clearly and obviously true. Now
our tendency is to assume the more threatening
propose a hypothesis that is ridiculous and
option. This was discovered in Matthew Walker’s
untrue about the item you are thinking
University of California, Berkeley, lab. Regarding
about. Can you see that if you look only for
how misinterpreting neutral facial expressions
reasons your ridiculous hypothesis is true,
as threatening could cause harm, Andrea Gold-
it is very likely you could find at least one
stein, lead author on the study, urges, “Consider
reason and decide to conclude that your
the implications for students pulling all-nighters,
hypothesis is true? What is missing? If you
emergency-room medical staff, military fight-
want to uncover the truth, you must also
ers in war zones and police officers on graveyard
seek to disprove your hypothesis.
shifts.” One of the fascinating aspects of the study
was that they studied the participants in an MRI
scanner, so in addition to having the evidence
Emotional Intelligence
reported by the subjects themselves, the scientists
One of the pillars of healthy interpersonal relation- could also see how well (or poorly in the case of
ships is emotional intelligence, which includes the less REM sleep) their brain structures were doing
capacity to understand and control one’s own emo- in terms of distinguishing between the different
tions and to recognize and interpret the emotions expressions.

Figure 5.9 Facial expressions

 Dreams: How and Where Dreams Are Created • 81

with their waking experiences, interpretations of

Retrieval Practice dreams generated according to this model still pro-
vide an opportunity for personal insight.
Start at the beginning of the chap-
Debate about the activation-synthesis model
ter and skim the content through to
continues, but there is no debate about how the
the end of this section, noting all the
advent of magnetic resonance imaging (MRI) has
reasons we dream. Then set aside
increased awareness of many additional brain
the content and your notes and
regions that are active during dreaming. Contem-
do not let yourself look at that material. Relying
porary research has utilized MRIs to provide a win-
only on your memory, make a list of all reasons for
dow into dream-related brain activity, showing high
dreaming. After you are done honoring that you
levels of activation in brain regions associated with
were able to retrieve some of the content on your
feeling emotions, creating movements, and com-
own, open the book and your notes and make addi-
prehending visual scenery (figure 5.11). Surprisingly,
tions and corrections to your retrieval practice list.
some of the brain structures, such as the amygdala,
Now if someone asks you, “Why do we dream?”
anterior cingulate gyrus, and hippocampus—parts
do you feel like you are ready with a concise and
of the “emotional brain” or limbic system—are even
interesting answer? Retrieval practices are one way
more active during dreaming than when we are pro-
to memorize fascinating content so you can gift
cessing information in our waking state.
it to others during your next conversation.
In sharp contrast to the activation-synthesis
model, neuropsychologist Mark Solms proposes
that dreams are created in the cerebral cortex,
How and Where Dreams Are Created
specifically the ventromedial prefrontal cortex
In the 1970s, Harvard medical doctors J. Allan (figure 5.12). This part of the brain is involved in
Hobson and Robert McCarley postulated a neuro- a range of functions such as goal-seeking, regu-
biological model of dreams. They described REM- lating challenging emotions, recognizing facial
associated bursts of electrical activity in cats as expressions, and processing risk. It also provides
originating in the pons (a part of the brainstem), connections between the limbic system and the
traveling through the thalamus, and arriving at frontal cortex. In the early half of the twentieth
the cerebral cortex (figure 5.10). Along with this century, this was one of the brain regions destroyed
neuronal activity came twitches in whiskers and in attempts to treat mental illness. Solms found
muscles, as well as jerky eye movements not typical
of a cat tracking something visually, which there-
fore seemed random. The brainstem’s electrical
activity patterns were not similar to those seen
in animals processing real sensory information
either; however, the cortex, influenced by this cha-
otic activation, was still trying to make sense of the
activity and synthesizing the brainstem activity
into a dream. This is the premise of Hobson and
McCarley’s activation-synthesis model of dream
creation. For some people, the activation-synthesis
model makes a case for dreams being meaning-
less, since they are based on seemingly random
activity. However, if we consider that the dreamer
interprets dream content based on its relationship Figure 5.10 The pons is highlighted in red
 82 • Dreams: How and Where Dreams Are Created

dreams, as it still relies on the visual association

cortex—the part of the brain that processes more
complex visual information.
Rather than looking at particular brain struc-
tures for the source of dreams, Harvard Medical
School sleep researcher Robert Stickgold asked par-
ticipants to look at the events and emotions of their
days for the source of dream content. Participants
kept diaries of their daytime activities and their
dreams. The dreams were not a replay of daytime
events. However, the worries and emotional themes
of the day were often incorporated into the dreams.
Figure 5.11 In the MRI If we leave the activation-synthesis model behind
in favor of theories such as Stickgold’s, suggesting
dreams contain meaningful information, then it’s
that patients with damage to this area, whether time to move to the next section for a discussion of
from surgeries or other injuries, did not dream. how to interpret dreams.*
In this chapter, we are focused primarily on
REM dreams, but let’s briefly consider the activ-
ity of the limbic system during NREM dreams,
which we know are bland and lacking in emotion.
So it follows that the limbic system is quite mellow
during NREM dreams.
On the other hand, it turns out, if we look fur-
ther, that there are brain areas that become inactive
during REM dreams as well. When we consider
the bizarre and sometimes embarrassing things
we do in REM dreams, the deactivation of one of
these brain regions in particular makes perfect
sense: the prefrontal cortex, which guides you to
use good judgment and be sensible and socially
appropriate, has exceptionally low activity during
dreaming (figure 5.13). Another area that seems to
almost drop out of the game during REM dreaming
is the primary visual cortex. This region of your
brain is involved in consciously detecting visual
stimuli from your eyes, so it is logical that, since
your eyes are closed while dreaming, the primary
visual cortex has almost no activity at that time.
The brain is still able to generate visual content for

* Magdalena J. Fosse et al., “Dreaming and Episodic Memory: A

Functional Dissociation?,” Journal of Cognitive Neuroscience 15, no. 1
(January 2003): 1–9, https://www.researchgate.net/publication/
10896475_Dreaming_and_Episodic_Memory_A_Functional
_Dissociation. Figure 5.12 Ventromedial prefrontal cortex
 Dreams: Interpretation of Dreams • 83

Figure 5.13 Motor and sensory regions of the cerebral cortex

for the dreamer. For example, the dreamer may

Interpretation of Dreams feel too ashamed to admit to a fantasy they are
Over five thousand years ago in Mesopotamia, having, so the content has to come to the dreamer
people were having their dreams interpreted and in symbols. (It was convenient for Freud that he,
looking to them for divine guidance (figure 5.14). as a self-proclaimed expert, could charge people
Throughout the years and around the world, dream money for these interpretations.) According to
interpreters and sometimes priests have been his approach, dreams contain two categories of
trusted to translate dream content into something content: manifest and latent. Manifest content
meaningful for the dreamer. With the emergence is the obvious material from the dream—the way
of the discipline of psychology in the nineteenth the dreamer would describe the dream. Latent
century, the practice began to include psycholo- content is the hidden material that indicates
gists as interpreters as well. the dreamer’s secret desires and fears. These
Sigmund Freud, an Austrian neurologist, repressed feelings, once revealed in a dream
believed dreams contained symbolic informa- analysis session, could be used to identify and
tion requiring interpretation by an expert. He treat a person’s problems. There is great value
thought dream content would be too disturbing in exploring and analyzing dream content, but
 84 • Dreams: Interpretation of Dreams

Figure 5.14 Mesopotamia

Freud’s particular method of dream interpreta- At around the same time that Freud and Jung
tion has been put to the test by scientific stud- were placing emphasis on the deep psychologi-
ies that have shown that different experts using cal meaning of dreams, Mary Whiton Calkins, a
his technique will come up with vastly differ- pioneer in psychology, was developing an oppos-
ent conclusions about the meaning of the same ing theory. As a part of her project at Clark Uni-
dream. These studies suggest a lack of reliability versity in Massachusetts, she examined over two
in his approach to dream analysis. hundred dream reports and concluded that dream
A psychiatrist colleague of Freud’s, Carl Jung, content is closely related to recent experiences,
disagreed with Freud on the need for dreams almost like a related replay of the day’s events
to be deciphered. Jung was convinced that the and sensations, and that dreams do not contain
same symbol means something different to each hidden meaning. She said, “In fact, my study as
person, so there was no use in trying to create a a whole must be rather contemptuously set down
book of dream symbols that could be applied as by any good Freudian as superficially concerned
a part of dream analysis. Instead, Jung thought with the mere ‘manifest content’ of the dream.”
our instincts convey wisdom to our rational mind Calkins must have been courageous not only for
via dreams. He said we were disconnected from challenging conventional wisdom about dreams
nature and our instincts because of modern soci- but because she was attending psychology semi-
ety, so we should use our dreams to reconnect and nars at Harvard with special permission, since
be transformed. women were not often allowed at the then all-male
 Dreams: Dreams in Different Cultures • 85

‘Ōlelo Hawai‘i
(Language of Hawai‘i)
‘Aumākua is Hawaiian for
“ancestral guardian spirits”
(figure 5.15).

college. She even fulfilled all the requirements for

a doctorate in psychology at Harvard, receiving
high recommendations from professors, includ-
ing William James, but the institution still refused
to grant her the degree since she was a woman. Figure 5.15 Green sea turtle
However, she went on to Wellesley College, where
she created a psychology lab—one of the first in
the nation—and became the first woman to serve Isis (who has nothing to do with the Islamic
as president of the American Psychological Asso- State terrorist group) for dream interpretation
ciation, soaring beyond Harvard’s discriminatory or incubation (figure 5.16). The dreamer might
policy. spend days preparing for dream incubation—a
time to encourage dreams rich in guidance—by
purifying themselves through ritualistic bathing,
Dreams in Different Cultures
fasting, and praying before sleeping in a tem-
Looking around the world to consider diverse atti- ple. After awakening from the dream, an oracle
tudes about dreams, a common theme is that many would be available to interpret the dream, which
view dreaming as an opportunity to connect with was especially valuable, since one of the strate-
the divine. In the Quran, one type of dream is called gies was to interpret dream content as the exact
ru’ya. Rather than being created by the dreamer’s opposite of its literal meaning. The temples were
mind, a ru’ya comes from God or the angels, and also available for visitors who had slept and
therefore a ru’ya is believed to have a purpose dreamt at home to consult with priests on dream
and meaning. There is a parallel in Hawaiian cul- interpretation.
ture in that dreams from spirits are thought to have
significance, in contrast to dreams the dreamer
created, which are thought to be meaningless and
pupule (crazy). In Hawaiian tradition, dreams are
part of the bond between the spirits of those who
are living and those who have passed. While a liv-
ing person is dreaming, the spirit leaves the body
through the lua‘uhane (“pit for the spirit,” which
is our tear duct) and travels to receive guidance
from ‘aumākua (ancestral guardian spirits) and
akua (gods).
Ancient Egyptians also used dreams to travel
in their dream body and connect with gods and
the spirits of the departed. People would visit the
temple of a god or goddess, such as the goddess Figure 5.16 Temple of Isis
 86 • Dreams: Lucid Dreaming

a person who is lucid dreaming can learn to control

Lucid Dreaming the content and progression of the dream. This
Bringing awareness that we are dreaming into the control is particularly beneficial when working
middle of a dream, opens another world for learn- with persistent nightmares because dream scen-
ing, creativity, resolving trauma, and more. Lucid ery and outcomes can be resolved and transformed
dreaming refers to the conscious realization that into something pleasant.
we are dreaming while still remaining asleep and Here are some steps to take if you would like to
deep in the dream. Taking things one step further, learn to lucid dream:

1. Develop skill at remembering dreams and them. You might also experience repeating
keep a dream journal. If remembering dreams elements, such as the appearance of a friend
is difficult for you, one strategy is to set an you have not seen in years or how you are able
alarm for two hours before you are supposed to fly if you run fast enough. For example, I am
to wake up in the morning. After the alarm a surfer, and in my dreams, water is colossal
goes off, remain in bed, eyes closed, and and defies the laws of physics (figure 5.17).
still. Try to recall the last feeling or thought
4. Combine the previous two steps to increase
in your mind. After you have that setting
awareness of whether you are dreaming. Tell
established, then go slowly backward in your
yourself ahead of time that if you see your
mind, trying to recall any other impressions.
friend from kindergarten or if you notice
In general, to help improve your dream recall,
you can fly when you flap your arms, you will
sleep at least eight hours, because then you
know you are dreaming.
will be more likely to awaken after a long
REM period with the vivid dreams that are
associated with that stage of sleep.

2. Take stock numerous times during the day to

notice you are not dreaming. Increase your
awareness of the nondreamlike qualities
of your waking state: Every time you look
at your phone or your watch, the color and
shape remain the same. If you are talking to
someone, they do not spontaneously turn
into someone else. Doing this several times
during the day trains your brain to notice the
Figure 5.17 The wave
details that indicate the waking state. This
task is in contrast to the next step.
5. Set an alarm to awaken in the middle of
3. Notice things about your dreams you do not the night. After it goes off, keep your eyes
experience in your waking state. The idea closed and hold still, recalling the recent
is to become intimately familiar with your dream. Meditate on the dream and tell your-
dreams. During dreams, people do turn into self you are going to fall back asleep into the
other people spontaneously, and your phone same dream and you will be aware you are
or your watch may change shape or color if you dreaming. Hopefully, you will drift into a
look away and then look immediately back at pleasant lucid dream.
 Dreams: Conducting a Dream Group • 87

Conducting a Dream Group

This is best done in a group of four to six people
seated in a circle but is still satisfying and produc-
tive in groups of different sizes (figure 5.18). It is
reassuring to state at the beginning that noth-
ing shared in the group will be discussed outside
of the group. Everyone is responsible for keeping
the group on track with the steps, but it is help-
ful to designate a leader to take that responsi-
bility. A different person takes over the role of
Figure 5.18 Stretching together before the discussion leader when the group finishes all the steps and

Dreamer Tells the Group the Entire During the retelling, the dreamer is encour-
Dream aged to add in details and share thoughts or
Everyone writes down the dream as brief notes theories as they arise.
in preparation to later read it back to the group. At any time, group members may ask addi-
tional open-ended questions, similar to those
Group Members Ask Questions in the second step.
Go around the circle and ask the dreamer about
their recent experiences (or those close to the Group Member Projections
time they had the dream, if it is not a recent Go around the circle, with each group member
dream). This is to establish emotional context. projecting their ideas as if the dream were their
Sample questions might include the following: own. For example,
Anything on your mind, like a book or “If I dreamt about ______, it might
something else you read, a TV show or
mean ______.”
movie, a phone call? Anything going on
at work/school? What’s happened lately Each group member is not meant to guess
with friends/family? what it means to the dreamer; rather they are
projecting what it would mean to themselves.
Avoid asking “Why do you think you had
The dreamer shares any epiphanies as they
______ in your dream?” This is too direct.
come up during the projections. Even if the
Rather, ask “Do you have any recent experi-
dreamer finds a projection completely unre-
ences with ______?”
latable to their own experience, that is also

Group Members Read the helpful, as it rules out possibilities on the way
Dream Out Loud to gaining insights.
Go around the circle, with each person reading a
small part of the dream, in order, from the notes Open and Unstructured
they created when the dreamer shared their Conversation
dream in the first step. In this way, the dream Freely discuss and continue to analyze the
is retold by group members with the dreamer dream until the group is ready to move on to
listening. This often prompts the dreamer to the next person and their dream. At the end,
recall more details from the dream. everyone thanks the dreamer for sharing.
 88 • Dreams: Conducting a Dream Group

finishes the analysis of one dream before moving after the final step. The group should work on one
on to the next person’s dream. Revelations about dream at a time, going through all the steps and
each dream’s meaning will arise throughout the including the final open discussion about inter-
process, usually in pieces, and the interpreta- pretation before moving on to the next person
tion discussion can continue without structure and their dream.
 6
Sleep Disorders

Student Learning other problems with no benefit or, at most, per-

haps twenty additional minutes of sleep a night.
Objectives We need to advocate for ourselves and loved ones
After you read this chapter, you will be able to to get health-care practitioners to persevere until
• differentiate between poor sleep due to we know what is causing daytime drowsiness and
unhealthy habits and that which is caused get it treated. Our lives depend on it.
by a sleep disorder
• describe several sleep disorders as well as Insomnia
their etiology and potential treatments,
including holistic approaches Many people who suffer from poor sleep think they
have a disorder called insomnia. However, most peo-
ple who believe this actually have a particular factor
causing their poor sleep, and such factors can usually
Introduction be addressed—the sleep is improved and insomnia
While a disorder such as obstructive sleep goes away. It is rare for a person to have insomnia not
apnea—not breathing during the night—is very caused by something else, such as stress, physical
serious and has lethal consequences, it is also pain, medication, a psychiatric disorder, a physical
essential that other, seemingly more subtle sleep illness, or poor sleep-health habits. These are what
disorders, such as periodic limb movements, get I mean by “factors” causing insomnia.
diagnosed and treated. For example, if someone The most straightforward factors to address
has daytime sleepiness, and sleep apnea has been are poor sleep-health habits. Refer to chapter 1
ruled out, the person still needs to find out what is to identify and determine strategies to attend to
leading to their sleepiness. In chapter 1, we have habits disturbing your sleep. That chapter also has
covered sleep debt and its serious consequences, detailed instructions for several techniques to alle-
such as depression, stroke, heart attack, obesity, viate insomnia as well as recommendations for
diabetes, and more. Therefore, we must not take effective treatments; the gold standard is cognitive
lightly any condition that disrupts sleep. In my behavioral therapy for insomnia. For many people,
workshops, I have met people all over the world following the guidelines in chapter 1 will fix their
who tell me they had undergone sleep studies sleep. If not, a sleep specialist can determine what
in which, after apnea was ruled out, they were other factors need to be addressed and develop a
sent on their way with no further investigation treatment approach. Once all these factors have
or advice. Or worse still, they were given a pre- been addressed, if the person is still not sleeping
scription for sleeping pills, which are not meant well, then a clinical sleep study may be necessary
as a long-term solution and can lead to countless to identify an underlying sleep disorder causing
 90 • Sleep Disorders: Snoring

Figure 6.1 Mouth and pharynx

the insomnia. But for most people, their sleep will locations, such as the nasal passageway or between
be restored before they get to that stage. the lips, that can cause snoring. It often occurs during
inhalation but also happens with exhalation. Con-
suming alcohol, smoking cigarettes, or having nasal
Snoring congestion from a cold worsens snoring, as can being
Have you ever noticed that if a snoring person rolls on overweight or pregnant. While some snorers have no
their side, it sometimes brings even the most skull- idea they are snoring and will swear, “I never snore,”
shattering sound to a halt? Snoring can be caused by others will awaken themselves with the noise. Heavy
the architecture and muscle tone of the structures snoring might be an indication of obstructive sleep
in and around the pharynx, which is made up of the apnea, but not always. Because of the potentially lethal
nasopharynx, oropharynx, or laryngopharynx (fig- consequences of obstructive sleep apnea, if a heavy
ure 6.1).* During sleep, the waking-state muscle tone snorer is also sleepy during the day, it is important
is lost and this tissue closes in to varying degrees and to consider a sleep study to rule out apnea. This path
vibrates as the breath moves past. There are other of preventative medicine may save the snorer’s life.

* See also Capital Otolaryngology Head and Neck Surgeons, “What Causes Snoring and Obstructive Sleep Apnea?,” YouTube video,
accessed May 5, 2021, https://www.youtube.com/watch?v=i5p0I-Jvtss.
 Sleep Disorders: Central Sleep Apnea • 91

Treatments for snoring include side sleeping, los- despite the vibration of the tissue. In contrast, with
ing weight (if overweight), eliminating nicotine, and OSA, the air is blocked for a varied amount of time,
avoiding or reducing alcohol. There are also many happening a few or hundreds of times each night,
devices that can help, from inexpensive over-the- often without the sleeper having any idea. Heavy
counter gadgets to costly oral appliances designed by snoring can be an indication of OSA, but also people
dentists trained in sleep medicine. The range of effi- who do not snore at all might still have OSA. Waking
cacy of these devices is broad, with the same device up with headaches, feeling sleepy during the day,
working well for one person and not at all for another. and having cognitive decline or unexpected weight
One of the populations overlooked in regard gain are all OSA symptoms. OSA is diagnosed with a
to sleep disorder–related breathing is children, sleep study, and now there is also at-home equip-
even though up to 15 percent of them may have it. ment that can be used in many cases, making it even
It is disconcerting that 90 percent of such cases easier to take this crucial step to improve health.
are undiagnosed. It can be associated with head- Once OSA is diagnosed, there is an assortment
aches, irritability, bedwetting, and of course, day- of choices for treatment, including weight loss (if
time sleepiness. Causes range from problems with a person is overweight), quitting smoking and/or
tonsils to irregular facial bone development, so drinking alcohol, sleeping with an apparatus to keep
engaging a pediatric otolaryngologist (ear, nose, the person on their side, and using oral appliances
and throat physician) can be impactful. or devices that keep the airway open with air pres-
sure. Continuous positive airway pressure (CPAP)
consists of a piece that goes over the mouth and/or
Obstructive Sleep Apnea nose connected to a hose that supplies a flow of air to
The statistics surrounding obstructive sleep apnea keep the airway open. There is an array of shapes and
(OSA) are alarming when we consider it occurs in sizes, so if a patient is not comfortable wearing what
more than one in four adults between thirty and they are given, it is important that they advocate for
seventy years old, with over 80 percent of cases themselves to get a more comfortable device (fig-
undiagnosed. If a risk factor such as having post- ure 6.2). There are also oral appliances that can hold
traumatic stress disorder or being overweight is the tongue or move the jaw forward, and these do
added to the equation, the likelihood of having OSA not rely on an airflow machine. Some patients resort
increases dramatically. OSA can cause diabetes, to surgeries, but they are typically not as effective
weight gain, stroke, heart attack, high blood pres- as CPAP. Visit this Harvard Medical School website*
sure, and depression, so we must increase education for apnea resources and a video of retired basketball
and screening for OSA. But what is OSA exactly? The player Shaquille O’Neal going through the process of
airway is obstructed during sleep, and the oxygen being diagnosed and treated for his OSA.†
levels in the body and brain drop, with associated
damage to tissue depending on the severity of the
Central Sleep Apnea
disorder. If oxygen levels drop low enough, small
parts of the brain and the heart could die each night. Central sleep apnea (CSA) is a rare disorder com-
The reason airflow gets blocked is usually because pared to OSA and is associated with the brain not
the tissue of the throat or the weight of the tongue sending the signal to breathe.
closes off the opening in a manner more extreme Some cases of CSA are caused by problems
than snoring. Snoring allows the air to pass through, with the heart or kidneys or from taking opioids

* Division of Sleep Medicine, “Apnea: Understanding and Treating Obstructive Sleep Apnea,” accessed on December 3, 2021,
http://healthysleep.med.harvard.edu/sleep-apnea.
† Harvard Medical School, “Shaq Attacks Sleep Apnea,” YouTube video, 4:16, May 5, 2011, https://www.youtube.com/
watch?v=4JkiWvWn2aU.
 92 • Sleep Disorders: Sudden Infant Death Syndrome

the hearing pathway traveling through the brain-

stem. While the cause of SIDS is not known, certain
practices increase the risk and so are best avoided:
inhaling secondhand smoke, sleeping on soft sur-
faces, overheating, or sleeping on the stomach. The
current advice is to put babies on their backs to
sleep, use a firm mattress, and put babies in sleep
clothing or a sleep sack so covers are not necessary
(figure 6.4). Breastfeeding has also been shown to
dramatically reduce the risk of SIDS.

Restless Legs Syndrome

Having restless legs might not sound too bad, but
with an increased risk of depression and anxiety,
as well as the myriad consequences of poor sleep,
Figure 6.2 Continuous positive airway pressure (CPAP) restless legs syndrome (RLS) has far-reaching
consists of a piece that goes over the mouth and/or nose repercussions on a person’s life. This arises from
what is often an indescribable sensation—perhaps
for longer than two months. The concept of CSA is tingling or itching—that triggers an overwhelming
similar to OSA in that the person will be tired dur- urge to move the legs. The sensations tend to dis-
ing the day because they are not receiving enough rupt daily activities, such as riding in a car or sitting
oxygen when sleeping, but treatments will vary in a classroom, and they are deleterious to sleep.
depending on the cause. Sometimes the cause is unknown, but anemia,
diabetes, or pregnancy could give rise to RLS or
make it worse. Medications such as antidepres-
Sudden Infant Death Syndrome sants, allergy medications, over-the-counter sleep
Sudden infant death syndrome (SIDS) is not a sleep
disorder per se, but it is worthy of discussion in
this chapter. SIDS is the sudden, unexplained death
of an infant younger than one year old and is the
leading cause of death in children one to eleven
months old. The highest rates are in babies two to
four months old. Research suggests it is linked
to an abnormality in the brainstem. Studies are
underway to further investigate the possibility
of a hearing screening test to identify babies at
increased risk of SIDS. The connection may be

‘Ōlelo Hawai‘i
(Language of Hawai‘i)
Hā is Hawaiian for “breathing”
(figure 6.3).
Figure 6.3 Hā
 Sleep Disorders: Bruxism • 93

rarely, movements are also in the arms. These com-

mon leg movements often do not disrupt the sleeper
and, if that is the case, would not be considered a
disorder. In fact, a sleeping partner is the one who
may have their sleep disrupted, while the person
with PLM is snoozing peacefully. If the movements
do disrupt the sleep of the person with PLM, at that
point, it is considered a disorder and will have all the
consequences of poor sleep.

Sleep Leg Cramps

Almost everyone will experience sleep-related leg
cramps at least once in their life, but some individ-
uals have several of these intense and painful mus-
cle contractions every night. Both the cramp itself
and the lingering pain make it difficult to sleep.
Sleep leg cramps are more likely in the presence
of diabetes, dehydration, electrolyte imbalance
(including potassium, calcium, or magnesium),
diuretics, and some medications. While strenuous
exercise is sometimes listed as an aggravating fac-
tor, the association might be more about a lack of
rehydration, stretching, or electrolyte replacement
Figure 6.4 Back to sleep after the strenuous exercise rather than the exer-
cise itself. In most cases, daily exercise, including
drugs, and antinausea medications can cause and stretching, helps prevent leg cramps (figure 6.5).
In addition to a daytime exercise program, light
aggravate RLS.
exercise—like a walk or gently riding a stationary
Exercise may relieve the symptoms of RLS, but
bike—for a few minutes before bed can fend off
interestingly, exercising with too much intensity
cramps. During the cramp itself, stretching, walk-
can increase them. Stress-reducing and muscle-
ing, massaging, and heat provide relief. Health-
relaxing practices such as yoga, meditation, warm
care practitioners are able to determine if there are
baths, and massages mitigate the symptoms and
imbalances (such as an electrolyte imbalance) or
promote sleep. Eliminating nicotine, alcohol,
other medical conditions that, when treated, will
and caffeine is crucial. resolve the leg cramps.

Periodic Limb Movements Bruxism

Occasionally people confuse periodic limb move- Strongly clenching the jaw or grinding the teeth
ments (PLM) with RLS, but they are separate disor- during sleeping or waking states is called bruxism.
ders. While RLS sensations cause the urge to move As a sleep disorder, the episodes happen from a
the legs, PLM is an unconscious and uncontrollable few to hundreds of times each night. Depending
movement itself. The big toe or leg moves a couple of on its severity, bruxism can damage teeth, dis-
times a minute for up to an hour. Sometimes, though rupt sleep, and lead to headaches or pain similar
 94 • Sleep Disorders: Sleep Paralysis

Figure 6.5 Stretching

to an earache. In many instances, people who are the times it occurs. An episode of a few seconds
have bruxism are wholly unaware. Risk factors are or minutes may happen several times a year or only
stress, anxiety, anger, frustration, extreme com- once in a lifetime. A person is unable to speak and
petitiveness, hyperactivity, medications (includ- cannot move except to breathe and move their eyes.
ing antidepressants), nicotine, alcohol, caffeine, Most of the people I have worked with who have
and some mental and physical health disorders sleep paralysis have reported visual hallucinations,
(such as gastroesophageal reflux disease). To aid such as seeing a person at the foot of the bed, and
in resolving bruxism, consider cognitive behavioral also feelings of anxiety during the episode (fig-
therapy (for anxiety, stress, etc.) and relaxation ure 6.6). Being sleep deprived or stressed or having
strategies such as mindfulness, meditation, and an irregular sleep schedule increases the likelihood
yoga, as well as addressing the risk factors. Oral of having sleep paralysis. It is also associated with
appliances—similar to mouth guards—protect the particular medications, narcolepsy, and psychiatric
teeth during sleep but do not address the disorder. conditions, including bipolar disorder. Other than
ruling out and addressing mental or physical health
problems and narcolepsy, the treatment usually
Sleep Paralysis involves attending to stress and getting regularly
Since it is normal to be paralyzed during REM sleep, scheduled eight-hour sleep sessions each night.
“sleep paralysis” does not sound like a disorder, To reduce their anxiety, I have coached people on
but it is. Perhaps it should be called “presleep meditation and breathing techniques to use during
paralysis” or “postsleep paralysis” because those the paralysis. They have all reported to me that the
 Sleep Disorders: REM Sleep Behavior Disorder • 95

Figure 6.6 Sleep paralysis hallucination

practice makes them feel less aversive and fear- that match their observed movements. This can
ful of the episodes, and consequently, their sleep happen four times a night, every night, or as rarely
quality improved. as once a month. The sleeper does not have aware-
ness of the episode. Alcohol use (and withdrawal),
certain medications, and sleep debt exacerbate
REM Sleep Behavior Disorder RBD. Because more than one in three people with
When the normal paralysis of REM sleep does not Parkinson’s disease also have RBD, health-care
take over, a person will act out their dreams by practitioners recommend monitoring RBD patients
jumping, shouting, swinging their arm, or what- for signs of Parkinson’s so early treatments to slow
ever happens to be taking place in the dream (fig- the course of the disease can begin immediately.
ure 6.7). This is REM sleep behavior disorder (RBD). RBD patients are also at greater risk of experienc-
Unlike sleepwalking, a person with RBD will usu- ing other sleep disorders, such as narcolepsy and
ally have their eyes closed and rarely walk. Upon sleep apnea, so they require regular sleep studies so
awakening, they swiftly become alert and are able these other disorders can be diagnosed and treated.
to report their dream, which will contain activities RBD itself is usually treated with medication.
 96 • Sleep Disorders: Sleep-Related Eating Disorder

just a few times in a year or several times each

night, or even during a nap. Awakening someone
from sleepwalking can be very scary and disori-
enting to the sleepwalker. While it is a myth that
it is dangerous to awaken a sleepwalker because
they may die from the fright, it is in fact danger-
ous to awaken a sleepwalker too suddenly because,
in their confusion, they may attack and hurt you
or themselves. If you feel completely comfort-
able, gently guide the person back to bed, touch-
ing them as little as possible, coaxing them in the
right direction until they get into bed themselves.
Figure 6.7 Falling asleep That approach is risky, so the other option is to get
a safe distance away and make a noise, gradually
Sleep-Related Eating Disorder increasing in volume, until the person awakens.
They will startle, but at least you are out of harm’s
Getting up in the middle of the night for a snack
way. Then gently explain to them that they are all
might sound harmless, but that is not the only
right and were sleepwalking.
thing happening with sleep-related eating dis-
order (SRED). In this case, the person will typi-
cally binge eat quite rapidly and, since they are
not completely alert, could cut or burn them-
selves cooking. The foods they eat are also some-
times inedible items such as raw meat, coffee
grounds, or even cleaning supplies (figure 6.8).
Unlike a sleepwalker, who will likely be scared if
you awaken them, a person with SRED tends to
be angry and hostile when aroused from an epi-
sode. They may or may not have any memory of
the event, so it can be frightening to arise in the
morning to a messy kitchen and a stomachache.
Using antidepressants, sleep prescriptions, and
other drugs can cause SRED. Getting poor sleep
increases the frequency of these episodes. Typi-
cally, a doctor will prescribe medication to treat
the symptoms.

Sleepwalking
During slow-wave sleep in the first half of the
night, a person may walk, or sometimes run, out
of bed, with glazed-over and open eyes (figure 6.9).
They talk or engage in other behavior, sometimes
elaborate and/or inappropriate. Episodes can occur Figure 6.8 Midnight snack
 Sleep Disorders: Bedwetting • 97

own, nightmares are not a sleep disorder unless

they occur so often that they are making you lose
sleep. One of the difficulties is that since night-
mares occur during REM sleep, the dream is vivid,
so upon awakening, and even throughout the
next day, it can be a challenge to clear it from
the mind.
In contrast, when aroused from a night terror,
which usually occurs during slow-wave sleep,
with its associated dull dreams, there is usually no
memory of the dream. However, there is nothing
dull about the physiological response to night ter-
rors. A person awakens from a night terror with an
overpowering sense of fear and a pounding heart,
shaking and perhaps even screaming, jumping
out of bed, or striking out at someone. They are
also usually disoriented and slow to respond to
someone trying to soothe them. Night terrors are
typical during the first third of the night, when we
have the most slow-wave sleep, while nightmares
usually occur during the latter third of the night,
Figure 6.9 Sleepwalking can be dangerous during our longer periods of REM.
Nightmares and night terrors have a range
Alcohol, sleep prescriptions, stress, irregular of causes including antidepressants, high blood
sleep schedule, posttraumatic stress disorder, pressure prescriptions, alcohol, posttraumatic
asthma, premenstrual syndrome, fever, certain stress disorder, exhaustion, mental disorders, and
drugs, and sleep debt can cause sleepwalking. inconsistent sleep schedules. Treatments include
Mindfulness, meditation, hypnosis, and stress- addressing these factors as well as implementing
reduction strategies can treat it. It is also important stress-reduction and mindfulness practices. Imag-
to do a safety check in the bedroom and home to ery rehearsal therapy is a promising treatment as
minimize the harm that may come during an epi- well and has also helped reduce daytime trauma
sode. For example, make sure the sleepwalker will symptoms (see chapter 5).
not have easy access to prescription drugs, scis-
sors, or car keys, and put gates across stairways.
Now that you are familiar with sleepwalking,
Bedwetting
take a moment to compare it to REM sleep behavior A child might not be able to control their bladder
disorder. during sleep until they are five years old, so unless
there is bedwetting twice or more a week in a child
over five years old, it is not considered a disorder.
Bad Dreams, Nightmares, and Night
It is crucial that if a child wets the bed, their self-
Terrors
esteem is considered in the parent’s handling of it.
It is normal to have an occasional “bad dream,” In addition to being harmful to the child’s emo-
slightly distressing in its feeling. However, when tional health, shaming them for it is also known to
a dream is so upsetting that it causes you to wake make the bedwetting more severe and take longer
up, it is called a nightmare (figure 6.10). On their to resolve.
 98 • Sleep Disorders: Jet Lag

Figure 6.10 Nightmares

If a child has gone six or more months with- mental and physical health issues have been ruled
out bedwetting and then suddenly begins again, out, treatment should focus on minimizing any
it could be due to stress, a urinary tract infec- shame associated with bedwetting combined with
tion, constipation, or another disorder. In elderly behavioral therapies such as enuresis alarms and
adults, bedwetting may occur with dementia, positive reinforcement.
depression, or obstructive sleep apnea. Some
forms of diabetes also cause bedwetting. Rarely,
Jet Lag
hormonal imbalances could cause bedwetting
at any age. Normally, antidiuretic hormone Traveling across time zones can be ruinous to
(vasopressin) levels rise during sleep to keep your sleep schedule. You may find yourself wak-
the amount of urine produced low enough so the ing up in the middle of the night, wide awake and
bladder holds it all night. If these levels are too with no ability to go back to sleep, and during the
low, the bladder may fill multiple times during daytime, you may get hit with a strong and sudden
the night, so the person would need to wake up wave of uncontrollable sleepiness (figure 6.11).
repeatedly to go urinate in the bathroom and For many people, it takes one day for their cir-
might eventually be too tired to awaken. Once cadian rhythm to shift one hour, so in the days
 Sleep Disorders: Short Sleeper • 99

before a trip, try shifting your bedtime closer to Short Sleeper

that of your destination. Stay hydrated and avoid
Research suggests there is a genetic difference that
or have only minimal caffeine and alcohol during
changes the sleep need of a rare few—less than
the flight. Consider incorporating bright light in
1 percent of the population—so they need less
the morning or early evening, depending on the
than six hours of sleep a night. They never sleep
direction of the shift; daily exercise; and sched-
longer than six hours, even on weekends, and they
uled fasting. Some people find melatonin supple-
do not need naps. Every morning, they wake up
mentation shortly before bedtime on the night of
feeling refreshed; they do not have any drowsy
arrival or at the beginning of a red-eye flight to
periods during the day and so do not need caffeine
be helpful. Be cautious, and seek advice from your
or any stimulants to stay alert. This sleep pattern
health-care practitioner regarding melatonin
begins in childhood, lasts throughout life, and
because it interacts with some medications and
tends to be accompanied by other characteristics
natural remedies. Also, researchers have found
like a generally upbeat mood, less of a reaction to
that some melatonin supplements carry danger-
painful stimuli, and a somewhat manic personal-
ously high levels of the hormone (many times
ity. It is not possible to teach yourself to be a short
higher than what is stated on the bottle), and
sleeper, and if you need to sleep in on weekends,
some products labeled “melatonin” contained
wake up less than revitalized, feel drowsy during
no melatonin at all.*
the day, or need caffeine to stay alert, you are not

* Madeleine M. Grigg-Damberger and Dessislava Ianakieva, “Poor Quality Control of Over-the-Counter Melatonin: What They Say
Is Often Not What You Get,” Journal of Clinical Sleep Medicine 13, no. 2 (February 2017): 163–65, https://doi.org/10.5664/jcsm.6434.

Figure 6.11 Can’t sleep

 100 • Sleep Disorders: Delayed or Advanced Sleep-Wake Phase

Ready to Move On?

Most of us have met someone who says, “I do not need eight hours of sleep. I am fine with
six hours!” Maybe you even say that! Before moving on in this chapter, rehearse how
to engage someone in a dialogue to help them determine if they are one of the rare
few with this genetic difference. In addition to sharing the likelihood that someone is a short sleeper
(which is less than 1 percent), what questions could you ask the person? It is really quite simple: your
goal is to find out if they have sleep debt. Remember, many people are unaware they have sleep debt,
and it can be masked by stimulants such as caffeine and nicotine. In the section on determining sleep
need in chapter 1, there is a list of questions to figure out if someone is getting enough sleep:

1. After being up for two hours in the morning, if you were to go back to bed, would you be
able to fall asleep?
2. If you did not set your alarm, would you wake up automatically at the desired time, feeling
refreshed?
3. Without caffeine or nicotine during the day, would you easily stay awake and alert?
4. When you go to bed at night, do you fall asleep “when your head hits the pillow”?
5. Do you doze off during a boring meeting, conversation, or TV show?

If six or fewer hours of sleep a night is truly adequate for the person you are talking to, then
the answer would be “yes” to questions 2 and 3 and “no” to questions 1, 4, and 5. Question 4 is the
only one that is not obvious in terms of a “no” answer indicating adequate sleep. While some of
you believe it is a healthy sign to fall asleep immediately upon getting in bed, that in fact is a sign
of an extreme lack of quality sleep. It should take about fifteen minutes to fall asleep if a person is
getting enough good sleep each night. Regarding question 5, a person could assume they are get-
ting ample sleep and that it is normal to doze off if they had an exhausting day and are watching
a TV show in the early evening. However, these doze-promoting situations are simply unmasking
sleep debt, providing a signal that more sleep is needed.
Remember to also ask the person if they sleep in on weekends. A short sleeper would not do that.
I think you will be surprised how many putative short sleepers you will help by being able to connect
with them in this conversation and help them see that they need to get more sleep.

a short sleeper. Most people who sleep less than because their tendency is to stay up late and get up
eight hours a night are sleep deprived and are caus- late. A “lark” and “early bird” refers to those with
ing harm to their bodies and minds. ASP, who go to bed early and are up before dawn
(figures 6.12a and 6.12b). If someone with either
DSP or ASP is able to follow their natural rhythm
Delayed or Advanced Sleep-Wake Phase and still sleep eight hours peacefully each night,
There are two separate disorders, delayed sleep- their disorder may not cause problems in their life
wake phase (DSP) and advanced sleep-wake phase and require no treatment.
(ASP), categorized as circadian rhythm disorders If the person’s schedule does have to be
(see chapter 3). Someone with DSP might refer to changed—for example, due to school, family, or
themselves as a “night owl” or “night person” work commitments—research indicates that the
 Sleep Disorders: Narcolepsy • 101

could be four students on our campus suffering from

narcolepsy, which affects one in every two thousand
people. I have had several students with narcolepsy
in my classes, and their stories inspire me. They
have shared how they have coped and become out-
standing students, pursued their academic dreams,
and helped people in our communities.
The most notable symptom of narcolepsy is
extreme daytime sleepiness—indeed, sometimes
sleep attacks (sudden onset of sleep)—that may be
accompanied by cataplexy, a loss of muscle tone.
Cataplexy can be subtle, such as difficulty with
speech, or as severe as total paralysis, causing the
person to drop to the ground, sometimes causing
serious injury. A person with narcolepsy might not
Figure 6.12a Owl Figure 6.12b Lark
be completely alert when they are going through
their day—for example, while in the classroom,
use of melatonin, guided by a sleep specialist, is
talking to someone, or reading a book—and thus
effective in shifting the sleep schedule. Bright-
may face memory problems as well.
light therapy is also effective for both DSP and ASP,
Treatments for narcolepsy involve various med-
though with inverse timing. For DSP, bright lights
ications and prescribed sleep schedules, including
and blue light from devices should be avoided in
naps at regular times during the day. Exercising
the two hours before one’s desired bedtime, and
bright-light exposure (sunlight, if available)
should be sought at the time one wishes to wake
up. For ASP, light should be avoided in the morn- Retrieval Practice
ing, and sunglasses are recommended for those Start at the beginning of the chap-
commuting in the bright morning sun. Then, in ter and skim the content through
the afternoon and early evening, exposure to bright to the end of this section, making
light is important. Because sleep quality is dis- brief notes of all the sleep disorders
rupted if DSP and ASP schedules are shifted, cog- and treatments mentioned. Then
nitive behavioral therapy for insomnia is helpful set aside the content and your notes, and do not
(see chapter 1). let yourself look at that material. Relying only on
your memory, make a list of as many sleep dis-
orders and treatments as you can. After you are
Narcolepsy
done honoring that you were able to retrieve some
Some films use narcolepsy as a joke, depicting those of the content from your mind, open the book
afflicted as having a sleep attack, suddenly falling and your notes and make additions and correc-
asleep midconversation. I try to counter this in my tions to your retrieval practice list. The next time
classroom by humanizing narcolepsy, showing stu- someone talks to you about how sleepy they are,
dents interviews with people who have this disorder you can provide some insight about relevant sleep
to demonstrate that it is debilitating and difficult, disorders and treatments and perhaps encour-
not funny at all. At my campus of around eight thou- age them to consider talking to their health-care
sand students, I tell those in my classroom to look provider.
at the faces of their fellow students and know there
 102 • Sleep Disorders: Clinical Sleep Study

Your Next Actions for Justice

Everyone reading this book can do something to help those with sleep dis-
orders. Share what you know about sleep debt and how to fix it, increase
awareness of sleep disorders, and write a letter to a newspaper or your con-
gressperson to ask for increased sleep wellness initiatives. Read the next
chapter for more on how to get moving and make a change!

and avoiding alcohol, nicotine, and drugs are also spaces that feel like a nice hotel (other than the
helpful strategies. tiny wires placed on your head and in a few places
on your body).
That being said, there is one especially troubling
Clinical Sleep Study thought: Who has insurance, and of those who do,
Once a person has gone through the Sleep Wellness who can afford the copay? If we know sleep debt
Guide (see chapter 1) and put in place as many of its causes strokes, heart attacks, Alzheimer’s, diabe-
strategies as they can, if they are still experiencing tes, obesity, depression, and more, then whoever
daytime drowsiness, it is vital that they consider cannot afford to fix their sleep is at a huge disad-
a clinical sleep study to rule out a sleep disorder. vantage in terms of their health, which should be
As we’ve seen throughout this chapter, untreated a basic human right—especially in countries like
sleep disorders can lead to serious mental and the United States, where there is access to excel-
physical health consequences. Thankfully, most lent medical treatment . . . for those who can afford
insurance companies cover sleep studies, and the it. I encourage you to consider how you can help
experience itself is not unpleasant: most places bring sleep wellness education and access to clini-
have created comfortable and private sleeping cal sleep studies to everyone who needs it.
 7
Politics, Sleep, and You

Student Learning debt and also because people are often unaware of
their degree of sleepiness. People can experience
Objectives four seconds of sleep while driving, performing
After you read this chapter, you will be able to surgery, flying a plane—you name it—and not
• discuss the significance of sleep debt as a realize they are asleep. It is chilling to combine
community and global issue this information with the fact that one in three
• explain the social justice implications of Americans admits that at least once in the previous
sleep debt demographics month, they have put themselves in the driver’s
• describe various approaches to reducing seat even though they were finding it challenging
sleep debt on local and national levels, to keep their eyes open. More than 40 percent of
including business, school, and health-care adults report that they rarely or never get enough
settings sleep on weeknights. If legislators could see the
• determine a feasible way to have an impact deadly effects of drowsiness the same way they
on sleep debt in your community see those of drunk driving, perhaps we could moti-
• participate in an activity focusing on the vate them to support an effective educational and
intersection between sustainability and health-care movement to address our national
sleep sleep debt emergency.

Introduction
How would you react if you saw your bus driver,
your surgeon, or your pilot drinking cocktails while
performing their job? You would be appalled. Yet
sleepiness can be worse than drunkenness in terms
of its likelihood of causing an accident (figure 7.1).
Researchers have shown that sleep-deprived indi-
viduals drive more recklessly (hit more cones in
driving courses) and have worse coordination and
reaction time than those who are drunk. Sleepi-
ness in fact causes as many deaths and injuries
from car accidents as drunk driving. Those num-
bers are probably lower than they should be, since Figure 7.1 Sleepy driving causes as many deaths as
highway patrol officers do not have a test for sleep drunk driving
 104 • Politics, Sleep, and You: Economics

Figure 7.2 Sleep debt by country

Economics 1991–94, when he served as chair of the US

Congress–mandated National Commission on Sleep
An effective approach may be to talk to people about
Disorders Research. Yet still, we find our country to
the financial cost of sleep debt. One of my mentors
in social justice and antiracism work told me, “We be, in the words of US senator Mark Hatfield, a “vast
do this work because we know it is the right thing reservoir of ignorance about sleep, sleep deprivation
to do, but if we can show leaders how making these and sleep disorders” (figure 7.3). It may surprise you
changes is a way for them to save or make money, to know that Hatfield made this remark all the way
then we get their attention.” What is the financial
cost of sleep debt? $411 billion annually for the US.
This comes from a RAND Corporation 2016 report
that also listed the annual cost of insufficient sleep
for Japan ($138 billion), Germany ($60 billion), the
United Kingdom ($50 billion), and Canada ($21 bil-
lion) (figure 7.2).* If loss of life is not enough rea-
son to justify the allocation of resources for sleep
wellness education, saving hundreds of billions of
dollars each year should do it.
Valiant efforts have been made to help change
attitudes toward sleep in the US. William Dement,
known as the father of sleep medicine, dedi-
cated decades to the cause, in particular from Figure 7.3 US Capitol

* Marco Hafner et al., “Why Sleep Matters—the Economic Costs of Insufficient Sleep: A Cross-Country Comparative Analysis,”
Rand Health Quarterly 6, no. 4 (2017): 11, https://doi.org/10.7249/RR1791.
 Politics, Sleep, and You: Antiracism • 105

back in 1993, and yet sleep debt–related tragedies such as in the case of Alaska Natives, so some of
have been multiplying ever since. these terms are mixed into this section, depending
on the studies being cited.
The US Centers for Disease Control and Preven-
Antiracism tion analyzed data from over four hundred thou-
As we consider the need for action to address the sand adults and found the prevalence of healthy
issue of sleep debt, we should keep in mind race- sleep duration to be significantly lower in Native
associated inequities in sleep wellness. Is healthy Hawaiians / Pacific Islanders, non-Hispanic Black
sleep a luxury, afforded only to “non-Hispanic people, multiracial non-Hispanics, and American
whites”? Indians / Alaska Natives compared to non-Hispanic
Before moving on, it is important to clarify that whites, Hispanics, and Asians. This study is just
race is a social construct. There is no biological or one of several that have provided evidence that
anthropological evidence that humans come from there is racial inequality in sleep wellness. Harvard
different races. We are one race: the human race researchers reported that Black participants are
(figure 7.4). But race labels, such as Black, are a five times more likely to have insufficient sleep
part of this discussion due to the research, in which compared to other groups. Even when socioeco-
they are used to create groups for data analysis. nomic status is factored out, the Black participants
Sometimes, these groups have to do with ancestry, still get less sleep.* This has enormous implications

* Yong Liu et al., “Prevalence of Healthy Sleep Duration among Adults—United States, 2014,” Morbidity and Mortality Weekly Report
65, no. 6 (February 2016): 137–41, http://dx.doi.org/10.15585/mmwr.mm6506a1.

Figure 7.4 One race: The human race

 106 • Politics, Sleep, and You: Antiracism

when we consider which groups have the highest sexual orientation as well, so consideration for
rates of diabetes, obesity, high blood pressure, and sleep equity must go beyond race, to all groups
other sleep debt–related disorders. For example, experiencing discrimination and oppression. It
if Blacks and Native Hawaiians, two groups with makes sense that sleeping deeply would require
higher rates of those disorders, are getting poor the mind to be in a state of ease, knowing we are
sleep, and we know poor sleep can cause these dis- safe and free. The situation is exacerbated by
orders, we have an extra layer of responsibility to the reported connection between lack of sleep and
address the racial inequalities around sleep health. reduced opportunity for civic engagement, such as
It is important to point out that the scientific being able to safely and conveniently vote. Insuf-
community agrees that there are no innate bio- ficient sleep is associated with reduced political
logical reasons for the sleep differences based on participation and decreases in other measures of
race. Researchers suggest the experience of rac- social capital (figure 7.5).
ism, even in its subtlest forms, impacts a per- Thus sleep inequality research adds one more
son’s ability to sleep well and, in particular, to justification, on top of the mountain of reasons, for
enter the deep and restorative sleep of NREM 3. fighting racism. It also illustrates the importance
This likely plays a role in the poor sleep reported of developing targeted sleep wellness education
by those experiencing discrimination based on and health services for these groups.

Figure 7.5 Kapu Aloha. Find your cause and speak out!
 Politics, Sleep, and You: Antiracism • 107

Ready to Move On?

Another one of my passions is environmental conservation. My campus, Kapi‘olani
Community College, a part of the University of Hawai‘i, has a strong history of action
around sustainability. Mālama i ka honua means “to take care of the earth” in Hawai-
ian (figure 7.6). Years ago, I chose to incorporate a sustainability designation into my sleep science
course. Why? Because I believe sustainability, just like social justice, should be woven into the fabric
of what we do, rather than as an add-on. My goal was to challenge students, through a classroom
activity, to consider how they can relate sleep to
sustainability. The point is, we find opportunities
for action if we look hard enough.
Here are the guidelines in case you would like
to try it:
In small groups (or you can do it on your own),
create consensus on a definition of sustainability.
Do not look one up; this is about sharing what
sustainability means to you. Remember, sustain-
ability can be social, cultural, environmental, and
economic.
When all groups have agreed on one definition,
share it with the class. Figure 7.6 Hawai‘i standing with Standing Rock
After sharing those definitions, here are some #NoDAPL
others to consider:

• something that will remain diverse and produce indefinitely

• endurance of systems and processes
• a way to continue something indefinitely and remain healthy

The next step in the activity is to work within your group to create a concept relating sleep to
sustainability. Use any definition of sustainability. When your group is finished, create a title for
your concept and write it large and in color on the board. When all the groups have titles on the
board, each group shares their concept. Before you get to work on creating your concept, consider
these examples:

• Gardening: If you garden, you get exercise and more nutritious food, both things that will
help you sleep. By gardening for sleep wellness, you are also taking care of the planet because
you are not polluting the air and using gasoline driving to get that food, and you are not
purchasing the food in plastic packaging that would increase plastic waste.
• Going to bed earlier: If you stay up late at night rather than getting up early, you are
using electric lights for your activities instead of doing those activities in the early
morning sunlight. By going to bed earlier, you use less electricity and spend more time in
natural sunlight. This is sustainable because it reduces energy usage.
 108 • Politics, Sleep, and You: Business

Business of completing more work. The irony is that if we

are low on sleep, it will take us longer to finish the
Company leaders are in a strong position to make
work because of decreased cognitive and physical
their mark, and increase profits, by addressing
functioning. We, and our companies, would be bet-
employee sleep debt. One study of four large com-
ter served to call it a day, get a good night’s sleep,
panies in the US determined sleepiness was costing
and start new in the morning. But first, a company
them—in lost productivity alone—around $3,000
annually per employee. For the four companies in must develop a prosleep culture that supports this
the study, the yearly capital loss was over $50 mil- wise decision-making.
lion. On a national level, poor sleep causes on aver- In Japan, as part of a response to survey results
age, per person, eleven days of lost productivity in indicating that 90 percent of adults do not get
the US. In the United Kingdom, one in five workers enough sleep, some companies are paying their
report that they had recently arrived late to work employees to sleep. One Japanese company uses
or skipped work due to insufficient sleep. More a phone app to record hours of sleep, and if the
than one in four employees in Canada take sick employee reaches the target, they earn points to
days because of sleepiness. Sometimes the rea- use for cafeteria purchases. In the US, Ben and Jer-
son we don’t get enough sleep is because we are ry’s, Google, Huffington Post, and Nike have places
staying at our jobs late into the evening in hopes where staff can sleep while at work (figure 7.7).

Figure 7.7 Nap pod

 Politics, Sleep, and You: High Schools and Colleges • 109

Reboot, a marketing company in London, pro-

vides a peaceful room for napping. Many com-
panies around the world are seeing the benefit of
allowing their employees to work the hours bet-
ter matched to their chronotype: for example,
letting the night owls start their shift later in the
morning. Considering the impact of poor sleep on
cognitive function, productivity, accidents, and
illness, companies could get an enormous return
on their investment by supporting healthy sleep
for their employees.

Figure 7.8 Sleeping in class

High Schools and Colleges
An international comparison found that among even though most of them still begin much ear-
the fifty countries studied, the US has the most lier. Consider the short- and long-term impact of
sleep-deprived students. One in three high school insufficient sleep on teenage mental and physi-
students fall asleep in class, and although teenag- cal health, such as increased rates of depression,
ers need nine hours of sleep each night, most are anxiety, high blood pressure, obesity, and diabetes.
sleeping around seven or fewer; less than 10 per- Research suggests teen suicide, violence, and acci-
cent of them are getting enough sleep (figure 7.8). dents are reduced if teens are given the opportunity
African American and Hispanic students, as well as to get a healthy amount of sleep. In addition to
those from low-income households, get even less. educating families about the importance of sleep,
In Japan, half of high school students are sleeping convincing school districts to move to later start
six or fewer hours on weeknights. times would start a revolution with tremendous
Adolescent sleep deprivation is an alarm- and far-reaching impact. Along with higher aca-
ing epidemic. The American Academy of Pediat- demic achievement, school officials could boast
rics, the American Association of Sleep Medicine, about reductions in their students’ rates of illness,
and the American Medical Association have all depression, tardiness, and suicide.
identified insufficient sleep in adolescents as a If the traditional school start time is 8:00 a.m.
serious public health issue and recommend that and a student awakens at 6:30 a.m. to get ready and
high schools should not start before 8:30 a.m., catch a bus, it is almost impossible that the teen

Your Next Actions for Justice

Consider the range of topics covered so far in this chapter. Did any of these
resonate with you or spark motivation to get involved? Take a moment
to reflect and make a mental note: What is a simple next step you could take to
move this sleep wellness revolution forward? It could be reaching out to your
favorite high school teacher, asking if they would consider adding a tiny module on sleep wellness
to their curriculum, or maybe connecting with a small group to address sleep debt on your college
campus. Whether large or small, imagine taking that next step and get in touch intuitively with
where you see yourself having an impact.
 110 • Politics, Sleep, and You: High Schools and Colleges

could have gotten enough sleep: to get the nine programs, student jobs, and sports activities are not
hours most teens need, they would have to be sleep- affected by later start times, hopefully more states
ing by 9:30 p.m. Add to the equation their delayed will follow California’s lead (figure 7.9).
circadian rhythm, a normal physiological part of Get involved in your community by having
being a teen, and it is even more unlikely they would discussions with local school administrators
be able to pull this off, even under the best of cir- about the American Academy of Pediatrics 2014
cumstances. For their bodies, the experience of get- policy statement* and the Society of Behavioral
ting up at 6:30 a.m. would be like an adult getting Medicine position statement,† which are calls to
up at 4:30 a.m. every day for work. So it comes as no action, with compelling scientific evidence, for
surprise that schools that shift to a later start time delaying school start times. You can also con-
report a reduction in mental and physical health tact wise politicians such as US congresswoman
problems, alcohol and drug use, and traffic acci- Zoe Lofgren, who in 2017 introduced the ZZZ’s
dents, as well as increased academic success. to A’s Act as a House Bill to “direct the Secre-
In Japan, Australia, New Zealand, England, and tary of Education to conduct a study to deter-
Finland, they have had later school start times for mine the relationship between school start times
decades, and each of these countries has higher and adolescent health, well-being, and perfor-
achievement rates than the US on standardized mance.” An easy step for getting involved, and a
exams. In the fall of 2019, California became the first way to find a range of resources, would be to visit
US state to mandate later high school start times, startschoollater.net.
reflecting its value for its children’s health. Since When you were in school, do you remem-
studies have shown that bus scheduling, after-school ber having lessons about healthy foods and sex

* Au, Rhoda, et al. “School Start Times for Adolescents.” Pediatrics 134, no. 3 (2014): 642-649, https://publications.aap.org/
pediatrics/article/134/3/642/74175/School-Start-Times-for-Adolescents.
† Trevorrow, T., E.S. Zhou, J.R. Dietch, B.D. Gonzalez. “Start Middle and High Schools 8:30 a.m. or Later to Promote Student
Health and Learning.” Society of Behavioral Medicine, (November 2017): https://www.sbm.org/UserFiles/file/late-school-start
-statement-FINAL.pdf.

Figure 7.9 Golden Gate Bridge, San Francisco, California

 Politics, Sleep, and You: Health-Care Providers • 111

education, as well as classes emphasizing the

importance of physical fitness? Most people in the
US would answer yes. However, what about lessons
on the importance of sleep? Let’s encourage our
teachers and school administrators to incorporate
lessons on the importance of healthy sleep for aca-
demic and athletic performance, stable mood, safe
driving, and physical health. Getting children and
teens motivated to sleep well is a wise place to build
momentum for this much-needed sleep revolution.
Students fortunate enough to make it to college
are faced with further challenges. With the high
cost of tuition and textbooks, there is considerable
pressure on college students to work long hours
and take too many credits at once to finish school
early so they can get a job, leaving only a small
amount of time for sleep. In a survey of industri-
alized nations, with the adult population sorted
Figure 7.10 Zombies
by age, college-age people get the worst sleep. In
Korea, college students sleep on average 6.7 hours
student health centers for opportunities to pro-
per night, and I imagine many college students
vide sleep wellness education activities and find
reading this book wish they could get six hours. The
resources to create napping spaces.
connection between depression and poor sleep,
along with the high rates of depression and sui-
cide on college campuses, adds more urgency to Health-Care Providers
the issue. Surveying college students about their
The issue around sleep debt and health-care
sleep is one way to start conversations and increase
providers has three components. The first one is
awareness about sleep debt. This opens the door for
foundational: the lack of education on sleep well-
us to share resources about how to improve sleep.
ness and sleep disorders provided to our doctors
Illinois State University students made up their
and nurses. Studies report that the total amount
faces to look like zombies and walked around cam-
of time dedicated to sleep education in our doc-
pus handing out sleep kits as a part of their “Don’t
tors’ preclinical training is only fifteen minutes.
Become a Zombie” campaign (figure 7.10). Stanford
If they received more education, we could expect
University has a Refresh program that has been
a decrease in the current rate of sleep disorders
modified and implemented on many other cam-
that are left undiagnosed (95 percent).
puses as well, including Dartmouth, the Univer-
sity of Chicago, and the University of Iowa. These
programs teach students about the importance of
sleep health and provide successful strategies for
‘Ōlelo Hawai‘i
getting healthy sleep. Several campuses in the US,
(Language of Hawai‘i)
the United Kingdom, and Japan have also created
napping spaces for students. Some have beanbags Kahuna lapa‘au is Hawaiian
and others have cots in areas where students sign for “health-care practitioner”
up for a napping timeslot. Students can reach out (figure 7.11).
to their student government organizations and
 112 • Politics, Sleep, and You: Health-Care Providers

Figure 7.11 Wana (sea urchin) are a source of healing food in Hawai‘i

The second component is the lack of sleep- in Idaho surveyed a little over 1,200 patients who
health education and screening provided by health- were coming to the clinic for a variety of reasons
care practitioners (kahuna lapa‘au in Hawaiian) to (besides sleep disorders) and found over 60 per-
their patients. cent of them also had sleep disorder symptoms.
Primary care physicians should adminis- At that point, all but two of the patients had not
ter a sleep-quality questionnaire and screen been diagnosed. Imagine if we could general-
patients for sleep problems like how they ize this type of care and reduce illness, acci-
screen everyone for high blood pressure (fig- dents, and deaths related to sleep debt and sleep
ure 7.12). If a physician sees a patient for some- disorders.
thing as minor as a splinter, they still have the The third and final component is the demanding
medical assistant slap on a blood pressure cuff to shift work required of our health-care providers
screen for hypertension (high blood pressure). We and hospital workers. We must change the guide-
need to approach sleep-health screening in the lines for this because there are too many deaths and
same manner. Every patient should get surveyed; accidents clearly documented and linked to health-
then the survey data should be used as talking care provider sleep debt. For example, physicians
points to emphasize the importance of sleep and in their residency (the two to seven years they
address any problem areas. Drowsiness should be practice while learning their specialty) are work-
discussed and pursued. Patients should be asked ing with such high sleep debt that one in twenty
to keep ten-day sleep diaries and submit those report that they have killed a patient due to errors
in follow-up appointments. A primary care clinic they made because they had not gotten enough
 Politics, Sleep, and You: Your Next Steps • 113

debt–related accidents and deaths continue to

occur. To put it in perspective, in the US, the ACGME
mandates that the maximum number of hours a
resident can work per week is eighty, but many
European countries, whose medical programs still
have excellent success rates and train physicians
in a similar number of years, set the maximum at
forty-eight.‡ We need to increase awareness of the
tragic number of preventable deaths and injuries
associated with the sleep deprivation imposed on
our health-care providers and pressure the medical
Figure 7.12 Physicians have the potential to play a establishment to change.
critical role in sleep wellness

sleep (figure 7.13). In a survey of residents in a San Your Next Steps

Francisco hospital, over 40 percent of residents
The World Health Organization says we are in the
disclosed killing at least one patient due to sleepi-
midst of a “global epidemic of sleeplessness.” The
ness. Stanford University researchers have used the
Centers for Disease Control and Prevention report
multiple sleep latency test for years on numerous
that over 40 percent of adults said they had fallen
residents and nurses, and according to them, of
asleep during the day unintentionally at least once
all those respondents, only one person “was not
in the past month. In the US and Japan, more than
in the twilight zone of extreme sleepiness.”* Johns
65 percent of adults are not getting enough sleep.
Hopkins released a study in 2016 stating medical
The problem is not limited to industrialized societ-
errors are the third-highest cause of death in the
ies. A study of people living in rural, low-income
US, making medical errors the reason for 10 per-
communities without the trappings of industry
cent of all US deaths.† Knowing how sleep-deprived
in eight African and Asian countries found that a
medical workers are, it is not a leap to consider lack
of sleep playing a part in those medical errors and
therefore deaths.
The medical establishment needs to be held
accountable and revise the work schedules of our
health-care providers. The National Academies
of Science, Engineering, and Medicine gathered a
group of medical and scientific experts to examine
evidence and propose revised work schedules for
medical residents. For example, with these revi-
sions, they would get a five-hour break for sleeping
after working sixteen of their thirty hours in a shift.
However, the Accreditation Council for Graduate
Medical Education (ACGME) has done too little Figure 7.13 MedGlobal volunteer performs surgery at
to have much impact, and way too many sleep Al-Shifa hospital in Gaza Strip

* Rafael Pelayo, C. William Dement, and Krystle Singh, Dement’s Sleep and Dreaming (self-published, 2016), 430.
† Johns Hopkins Medicine, “Study Suggests Medical Errors Now Third Leading Cause of Death in the U.S.—05/03/2016,” Johns
Hopkins Medicine-News and Publications, May 2016, https://www.hopkinsmedicine.org/news/media/releases/study_suggests
_medical_errors_now_third_leading_cause_of_death_in_the_us.
‡ Pelayo, Dement, and Singh, Dement’s Sleep and Dreaming, 428.
 114 • Politics, Sleep, and You: Your Next Steps

awareness and access helped eradicate smallpox

Retrieval Practice and almost eradicated polio and other diseases.
Research on death in infants led to the Back to
Start at the beginning of the chap-
Sleep campaign to reduce the incidence of sudden
ter and skim the content through
infant death syndrome. Widespread distribution
to the end of this section, making
of posters provided education about reducing the
brief notes of a few of the most
spread of disease through handwashing. We know
compelling facts in each section.
we can have an impact, and now is the time to act
Then set aside the content and your notes and
to increase sleep-health education.
do not let yourself look at that material. Rely-
After completing my course on the science
ing only on your memory, make a list of as many
of sleep, or simply reading this book, you are likely
of the facts you can recall. After you are done
a sleep expert compared to most of the people in
honoring that you were able to retrieve some
your community, so I ask you to take that knowl-
of the content from your mind, open the book
edge and use it to make an impact on your commu-
and your notes and make additions and correc-
nity. You can read the previous sections for ideas,
tions to your retrieval practice list. Finally, look
but here are a few more:
over that list and select one of the topics that you
find to be the most interesting. Rehearse two
• Choose some sleep wellness and sleep
talking points on the topic so you can share them
disorders information (for potential
in a conversation that may give rise to someone
content, see chapters 1 and 6 in this book)
taking action.
and put it in a format you like—a flyer,
brochure, poster, or sheet of talking
points—and go with a friend to do targeted
large number of adults were not getting enough sleep-health education in underserved
sleep. The authors used their study’s results to urge neighborhoods. You might consider
people to see the global nature of the sleep debt visiting a beauty salon, barbershop,
epidemic.* church, or school to share your expertise
There are many approaches to resolving this (figure 7.14). A good way to start the
problem and decreasing its associated catastro- conversation is by asking people to tell you
phes. One place to start is to address the lack of about their sleep and their early evening
awareness about sleep debt and the dearth of public routines. People usually like to share their
policies promoting healthy sleep. stories. Your first step is to encourage
Let’s take a glance at previously successful dialogue about sleep.
campaigns that had impacts on public health. • Get resources from, or provide support to,
Thanks to scientific evidence about the dangers a nonprofit such as Pajama Program† and
of cigarette smoking, we saw the rise of con- help children get sleep.
sumer warnings added to packaging as well as • Reach out to educate leaders in occupations
designated nonsmoking areas. After learning known to have increased levels of sleep
more about automobile accidents, we went from debt: health-care workers, airline
cars not even having seat belts to passing laws employees, bus drivers, truck drivers, police
requiring that all passengers wear them. Vaccine officers, first responders, and military.

* Saverio Stranges et al., “Sleep Problems: An Emerging Global Epidemic? Findings from the INDEPTH WHO-SAGE Study among
More Than 40,000 Older Adults from 8 Countries across Africa and Asia,” Sleep 35, no. 8 (August 2012): 1173–81, https://doi.org/
10.5665/sleep.2012.
† “Pajama Program,” accessed on December 3, 2021, https://pajamaprogram.org/our-programs/.
 Politics, Sleep, and You: Your Next Steps • 115

• Talk to colleagues at work about their

sleep. Identify things at your workplace
that could change to support healthy sleep.
Approach an ally in a leadership role in your
company and discuss the financial gains
likely achieved if they adopted a prosleep
culture. Ask them to consider creating a safe
napping space, providing sleep disorder and
insomnia screening, starting a healthy sleep
awareness program, and adjusting shift
hours based on chronotype.
• Start a petition or grassroots effort to
eliminate daylight savings time.

Consider the successful business leaders, school

administrators, and politicians mentioned earlier
in this chapter, who have chosen to make healthy
sleep a priority for large groups of people and
achieved much along the way. Please find an arena
where you have a natural interest—perhaps a
school, a local political group, a veterans club, an
Figure 7.14 Start a sleep wellness conversation at the eldercare facility, a health clinic for the under-
barbershop served, your workplace or college campus—and
begin a conversation with someone about how to
• Visit your campus health center and ask raise consciousness about sleep wellness. Let’s
them to consider providing sleep wellness work together to help people get the sleep they
screenings and to discuss snoring, deserve so we can bring more equanimity, health,
insomnia, apnea, and daytime drowsiness. and peace to our communities and beyond.
 Image Credits

Image caption Attribution phrase Source/link

Figure I.1 Yawning Yawning little girl by https://pixabay.com/photos/yawning-little-girl
truthseeker08 / Pixabay -yawn-child-1895561/
Figure I.2 Dreams Dreams by Rogier Hoekstra / https://pixabay.com/photos/dreams-fantasy-art
Pixabay -surreal-2904682/
Figure I.3 105-year-old This woman is 105 years https://www.flickr.com/photos/82552101@N00/
woman old by Joe Green / CC 3133747764
BY-ND 2.0
Figure I.4 Some of Effects of sleep deprivation https://commons.wikimedia.org/wiki/File:Effects
the effects of sleep by Mikael Häggström _of_sleep_deprivation.svg
deprivation «Medical gallery of
Mikael Häggström 2014»
/ CC0 1.0
Figure I.5 Sleeping on it Sleeping on it by Sheryl https://drive.google.com/file/d/
Shook / CC0 1.0 1dAUcc5EekSgRlrz9dizd6HggVZGGm981/view?usp
=sharing
Figure I.6 Yawning is not Yawn . . . by Tancread / CC https://www.flickr.com/photos/69446921@N00/
just for humans BY-NC 2.0 83525962
Figure 1.1 Nap Nap by Bery1_snw / CC0 1.0 https://www.flickr.com/photos/beryl_snw/
14894872130/in/photolist-oGd7yb
https://drive.google.com/file/d/1jP4qUdYAP
-lumBIHo-xD0zD7j4I4FebY/view?usp=sharing
Figure 1.2 Kalahari Arri Raats, Kalahari https://upload.wikimedia.org/wikipedia/commons/
ǂKhomani San Bushman Khomani San Bushman, a/a4/Arri_Raats%2C_Kalahari_Khomani
Boesmansrus camp, _San_Bushman%2C_Boesmansrus_camp
Northern Cape, South %2C_Northern_Cape%2C_South_Africa_
Africa by South African %2819919544304%29.jpg
Tourism from South
Africa / CC BY 2.0
Figure 1.3 Siesta Woman Lying Down by Hy https://www.pexels.com/photo/woman-lying-down
Aan / Pexels -1768968/
Figure 1.4 Napping boosts Man Napping on Books https://www.pexels.com/photo/man-napping-on
learning by Oladimeji Ajegbile / -books-3564013/
Pexels
Figure 1.5 Skip the side Medication Pills Isolated https://www.pexels.com/photo/medication-pills
effects and choose on Yellow Background by -isolated-on-yellow-background-3683098/
to nap Anna Shvets / Pexels
Figure 1.6 Power naps for Womens Wheelchair https://unsplash.com/photos/u1CAj5HJzO4
power athletes Basketball by Audi
Nissen / Unsplash
 118 • Image Credits

Image caption Attribution phrase Source/link

Figure 1.7 Cozy amber Lighting Ceiling Lights https://pixabay.com/da/photos/lys-belysning
lighting by WaltiGoehner / -loftlamper-orange-459236/
Pixabay
Figure 1.8 Looking cool Man Wearing White Crew- https://unsplash.com/photos/QchkCq3w_UE
while blocking blue light neck shirt by Pedram
Normohamadian /
Unsplash
Figure 1.9 Elevate your legs Person Sitting on Couch https://www.pexels.com/photo/apartment
While Using Laptop -comfortable-contemporary-couch-269129/
Computer by Pixabay /
Pexels
Figure 1.10 Midsection view Male Reproductive System https://openstax.org/books/anatomy-and
of the male reproductive by Openstax / CC BY 4.0 -physiology/pages/27-1-anatomy-and
system -physiology-of-the-male-reproductive
-system
Figure 1.11 Think about your man getting can in https://unsplash.com/photos/OGlhEkaMot0
sleep before reaching for beverage cooler by
an energy drink NeONBRAND / Unsplash
Figure 1.12 Bedtime story Bedtime Story 2 by https://www.flickr.com/photos/97411961@N00/
Michael Gabelmann / 26397372635
CC BY-NC 2.0
Figure 1.13 Healthy snack Maple Granola by https://www.flickr.com/photos/84143785@N00/
for healthy sleep QuintanaRoo / CC 3470512747
BY-NC-SA 2.0
Figure 1.14 Pele emerging Hawaii Volcanoes National https://www.flickr.com/photos/66733752@N00/
from lava Park by Jasperdo / CC 6059308503
BY-NC-ND 2.0
Figure 1.15 Put a pillow Put a pillow between your https://www.wikihow.com/Improve-Your-Sleeping
between your legs legs by wikiHow / CC -Position#/Image:Improve-Your-Sleeping
BY-NC-SA 3.0 -Position-Step-1.jpg
Figure 1.16 Sleeping sleeping together by https://www.flickr.com/photos/frerieke/
together Frerieke / CC BY-NC 2.0 6268206497/in/album-72157627892036730/
Figure 2.1 Central and The Central and Peripheral https://cnx.org/contents/FPtK1zmh@15.5:yEs2p8R_
peripheral nervous Nervous Systems by @10/12-1-Basic-Structure-and-Function-of-the
systems Openstax / CC BY 4.0 -Nervous-System
Figure 2.2 Neuron and Neuron and Synapse by https://cnx.org/contents/FPtK1zmh@16.1:mYoZvS9p
synapse Openstax / CC BY 4.0 @9/12-2-Nervous-Tissue
Figure 2.3 The brain Brain Illustrations by https://ccsearch.creativecommons.org/photos/
Denise Wawrzyniak / CC 51f88f19-c521-4af4-bdb0-642dfbd6a161
BY-NC 4.0
Figure 2.4 The brainstem The Brain Structures That https://thebrain.mcgill.ca/flash/d/d_11/d_11_cr/d
Wake You Up and Put You _11_cr_cyc/d_11_cr_cyc.html
to Sleep by Bruno Dubuc /
copyleft
 Image Credits • 119

Image caption Attribution phrase Source/link

Figure 2.5 The diencephalon The Diencephalon by https://openstax.org/books/anatomy-and
shown in a midsection Openstax / CC BY 4.0 -physiology/pages/13-2-the-central-nervous
view of the brain -system
Figure 2.7 Nuclei of the Hypothalamus drawing by https://drive.google.com/file/d/
hypothalamus KCC Library / CC0 1.0 1NKF1ktDfKHQVHTbt0JxnytEZEc2wpib3/view?usp
=sharing
Figure 2.6 Ipo Love is on the way by https://flic.kr/p/dEycCQ
Micah Camara / CC
BY-NC-ND 2.0
Figure 2.8 Lobes of the Brain lobes by BruceBlaus, https://en.wikiversity.org/wiki/WikiJournal_of
human brain Blausen.com staff (2014) / _Medicine/Medical_gallery_of_Blausen_Medical
CC BY 3.0 _2014#/media/File:Blausen_0111_BrainLobes.png
Figure 2.9 The insula Insula Structure by https://en.wikipedia.org/wiki/File:Insula_structure
Schappelle / CC .png
BY-SA 4.0
Figure 2.10 The limbic Limbic system by https://en.wikiversity.org/wiki/WikiJournal_of_
system BruceBlaus, Blausen.com Medicine/Medical_gallery_of_Blausen_Medical
staff (2014) / CC BY 3.0 _2014#/media/File:Blausen_0614_LimbicSystem
.png
Figure 2.11 Polysomnogram Polysomnography Tester https://commons.wikimedia.org/wiki/File:
by 邱鈺鋒—自己的作品 / CC Polysomnography_tester.jpg
BY-SA 4.0
Figure 2.12 Baby connected EEG Baby by Tess Dixon / https://flic.kr/p/nrWgpL
to EEG CC BY-NC-ND 2.0
Figure 2.13 Wave amplitude Wave amplitude and https://drive.google.com/file/d/
and frequency as well as frequency by 1sBTrpMGrvpecJVtF1PcoRKNMLBCVjsKU/view
a K-complex and sleep NeoCadre and Knott / ?usp=sharing
spindle CC BY-SA 3.0
Figure 2.14 Waves in hawaii by Konstantin https://www.flickr.com/photos/29548659@N05/

Hawai i Maximov / CC BY 2.0 9680029147/in/album-72157635393461433/
Figure 2.15 Riding the man in black shorts surfing https://unsplash.com/photos/dHKXktPp36A
perfect wave on sea waves during
daytime photo by Barbara
Rezende / Unsplash
Figure 2.16 EEG recordings Brainwaves by MIT Open https://www.google.com/url?q=https://ocw.mit
Courseware / CC .edu/courses/aeronautics-and-astronautics/
BY-NC-SA 4.0 16-400-human-factors-engineering-fall
-2011/lecture-notes/MIT16_400F11_lec19
.pdf&sa=D&ust=1610682088487000&usg=
AOvVaw27mKyOF4fmoTni363TNrM-
Figure 2.17 The Meaning of Sleep https://www.researchgate.net/figure/A-graphical
Polysomnography setup Quality: A Survey of -representation-of-the-polysomnography
and data Available Technologies - -technology-from-the-user-point-of-view_fig3
by Unknown / CC BY 4.0 _337243463 [accessed February 23, 2021]
 120 • Image Credits

Image caption Attribution phrase Source/link

Figure 2.18 The eye Physics of the Eye by https://openstax.org/books/college-physics/pages/
Openstax / CC BY 4.0 preface
Figure 2.19 EEG, EOG, and Typical polygraphic https://www.researchgate.net/figure/Typical
EMG recordings by Unknown / -polygraphic-recordings-during-the-wake-WK
CC BY 2.0 -stage-1-S1-stage-2-S2-light_fig1_230712986
Figure 2.20 NREM 2 EEG Stage 2 sleep by Neocadre / https://commons.wikimedia.org/wiki/File:
CC0 1.0 Stage2sleep_new.svg
Figure 2.21 Hypnogram of Hypnogram of sleep between https://en.wikipedia.org/wiki/Rapid_eye_movement
sleep between midnight midnight and 6.30 am by _sleep#/media/File:Sleep_Hypnogram.svg
and 6:30 a.m. RazerM / CC BY-SA 3.0
Figure 2.22 Actigraphy Actigraphy by Unknown / http://koreascience.or.kr/article/
device and data from a CC BY-NC 4.0 JAKO201535151793878.pdf
college student
Figure 3.1 Nodding off Man in long black sleeve https://www.pexels.com/photo/man-in-black-long
shirt sitting by RODNAE -sleeve-shirt-sitting-7581035/
Productions / Pexels
Figure 3.2 Circadian rhythm Biological Clock Human https://commons.wikimedia.org/wiki/File:Biological
by YassineMrabet / CC _clock_human.svg
BY-SA 3.0
Figure 3.3 ATP chemical ATP chemical structure by https://commons.wikimedia.org/wiki/File:ATP
structure cacycle / CC BY-SA 3.0 _chemical_structure.png
Figure 3.4 Circadian rhythm Circadian rhythm vs. sleep https://drive.google.com/file/d/
versus sleep pressure pressure by Hikialani 175eCOopRwpXdZCvXjzXlFSaWRrK5RZ0N/view
Guzman / CC BY 4.0
Figure 3.5 The cave behind Waianuenue by Thomas / https://flic.kr/p/MexbBD
Waiānuenue Falls CC BY-ND 2.0
Figure 3.6 Circadian Circadian Rhythm (p. 16) by https://www.google.com/url?q=https://ocw.mit
rhythm of physiological MIT Open Courseware / .edu/courses/aeronautics-and-astronautics/16
measures CC BY-NC-SA 4.0 -400-human-factors-engineering-fall-2011/
lecture-notes/MIT16_400F11_lec19.pdf&sa=
D&ust=1609878274190000&usg=AOvVaw1jz
_e1wv9eSleQE2xyr09P
Figure 3.7 How many Smiling coworkers in https://www.pexels.com/photo/smiling-coworkers
zeitgebers do you see in aprons using laptop -in-aprons-using-laptop-together-4353605/
this photo? together by Ketut
Subiyanto / Pexels
Figure 3.8 Neuroanatomy of Neuroanatomy of the https://ocw.mit.edu/courses/architecture/4-430
the circadian system circadian system (p. 6) by -daylighting-spring-2012/lecture-notes/MIT4
MIT Open Courseware / _430S12_lec11.pdf
CC BY-NC-SA 4.0
Figure 3.9 Light and dark Light, Suprachiasmatic https://commons.wikimedia.org/wiki/File:Light,
impact the pineal gland’s nuclei (SCN), and the _suprachiasmatic_nuclei_(SCN),_and_the
release of melatonin pinealmelatonin circuit _pinealmelatonin_circuit.jpg
by Ma Z, Yang Y, Fan C,
et al. / CC BY 4.0
 Image Credits • 121

Image caption Attribution phrase Source/link

Figure 3.10 During the Tromso Polar Night by https://flic.kr/p/9bQErF
winter, the sun does not Mariusz Kluzniak / CC
rise at all in Tromsø, BY-NC-ND 2.0
Norway.
Figure 3.11 Bright lighting Shallow Focus Photography https://www.pexels.com/photo/blur-children-class
in the classroom of Girl by Akela / Pexels -classroom-448877/
Figure 3.12 Lark and owl Collage by Jason Ford using https://drive.google.com/file/d/1dXnKm
Crested Lark by Koshy -BCFZcx9pPNuikGLA1uNlBf3fPn/view?usp=
Koshy / CC BY 2.0, and sharing
Owl by Eduardo Skinner /
CC BY-NC 2.0.
Figure 3.13 Storytelling Storytelling by Renu Parkhi https://flic.kr/p/Yu15z
/ CC BY-NC-ND 2.0
Figure 3.14 Shift workers SR 520 Pavement Repair https://www.flickr.com/photos/7821771@N05/
by WSDOT / CC 3379585174
BY-NC-ND 2.0
Figure 3.15 Flying into a N587HA Hawaiian Airlines https://flic.kr/p/2heXfZf
different time zone Boeing 767–33A/
ER (cn 33421/887)
«Pakalakala»—McCarran
International Airport
by Tomas Del Coro / CC
BY-SA 2.0
Figure 3.16 Caffeine Coffee at Cafe Reno by Cafe https://flic.kr/p/dbuexQ
impacts the circadian Reno / CC BY 2.0
rhythm.
Figure 3.17 Sleeping in Sleeping in Space by https://www.nasa.gov/image-feature/sleeping-in
space NASA / PD -space
Figure 3.18 Sometimes Collage by Jason Ford using https://drive.google.com/file/d/1QfIn
polyphasic sleeping Uberman Polyphasic -0L1Ai2KTIidDrjOQGu2Py-n6nO0/view?usp=
is referred to as the Sleep Pie Chart and sharing
uberman schedule. Biphasic Sleep Pie Chart
This figure compares by Master Uegly / CC0 1.0
polyphasic to biphasic
sleep. The circle
represents time in the
twenty-four-hour day,
so the small dark blue
sectors in the uberman
(polyphasic) schedule
are the six thirty-minute
naps. On the biphasic
image, the large dark
blue sector is eight
hours of nighttime sleep
and the small sector
is the twenty-minute
afternoon nap.
 122 • Image Credits

Image caption Attribution phrase Source/link

Figure 4.1 Delicious Delicious by Chris https://www.flickr.com/photos/72562013@N06/
Phutully / CC BY 2.0 8348522161/in/photolist-dHJmMg
Figure 4.2 Red ant Red ant closeup by John https://pixy.org/194468/
Pupkin / CC0 1.0
Figure 4.3 Shark Sleepy shark by Harry https://www.flickr.com/photos/harrymetcalfe/
Metcalfe / CC BY 2.0 5406228674/in/album-72157625949793722/
Figure 4.4 Australian Mature Eastern Water https://www.flickr.com/photos/gails_pictures/
dragon Dragon. Intellagama 15406633089/in/photostream/
lesueurii by
gailhampshire / CC BY 2.0
Figure 4.5 Honu honu by eggrole / CC BY 2.0 https://www.flickr.com/photos/35387910@N04/
3407763336
Figure 4.6 Safe sleeping Pretty Ducks All in a Row https://flic.kr/p/9wyCTe
with sentinels by Peter Radunzel / CC
BY-NC 2.0
Figure 4.7 Frigate bird Magnificent Frigatebird https://www.flickr.com/photos/concertsandcomedy/
(Female) 10—Blackbird 24764852212/in/album-72157664362602996/
Caye—Belize 2016 by
Adam / CC BY 2.0
Figure 4.8 Dolphins Dolphins by ryn413 / https://www.flickr.com/photos/42596236@N07/
CC BY 2.0 3952952164
Figure 4.9 Bat Flying Dog Aethalops https://pixabay.com/photos/flying-dog-aethalops
Mammal Fledertier -mammal-4136563/
Chiroptera by Hans /
Pixabay
Figure 4.10 Sea otters Romp of Otters. Sea Otter https://www.flickr.com/photos/mikebaird/
Mom with NOT Two 462500055/sizes/h/
Pups but ONE sea-otter-
mom-and-pup-4-
16-07_2 by Mike Baird /
CC BY 2.0
Figure 4.11 Sleeping sperm Sperm Whale Sleeping by https://www.nationalgeographic.com/photography/
whales Stephane Granzotto / All proof/2017/07/sperm-whales-nap-sleeping
rights reserved -photography-spd/
Figure 4.12 Hawaiian monk Hawaiian Monk Seal by https://flic.kr/p/8REb2L
seal dazegg / CC BY-NC-ND 2.0
Figure 4.13 Monotreme, Collage by Jason Ford / CC https://drive.google.com/file/d/1sj1OZ9BGaXDP
placental, and marsupial BY-SA 2.0 using Wild _7tWpW6NtEpbmju6h1FI/view?usp=sharing
mammals Platypus 3 by Klaus / CC
BY-SA 2.0; Melbourne
Zoo, Australia by Tom
Thanachart / CC BY-
SA 2.0; and Pregnant
Woman by Graham
Crumb / CC BY-SA 2.0
 Image Credits • 123

Image caption Attribution phrase Source/link

Figure 4.14 Ground squirrel Belding’s Ground Squirrel https://flic.kr/p/PyCom
by Ben Amstutz / CC
BY-NC 2.0
Figure 4.15 Bear Sleeping bear by https://www.flickr.com/photos/morpheus_uk/
Morpheus_uk / CC 363236339/
BY-NC 2.0
Figure 5.1 Under the covers Unrecognizable person https://www.pexels.com/photo/unrecognizable
sleeping under blanket by -person-sleeping-under-blanket-4546117/
Ketut Subiyanto / Pexels
Figure 5.2 We’ve all been The Socially Awkward Adult https://www.behance.net/gallery/54341681/The
there. by Neethi Goldhawk / -Socially-Awkward-Adult/modules/320531069
CC BY-NC-ND 4.0
Figure 5.3 Staying together Two Women Looking Up by https://www.pexels.com/photo/two-women-looking
Riya Kumari / Pexels -up-1404920/?utm_content=attributionCopyText
&utm_medium=referral&utm_source=pexels
Figure 5.4 Soldier Soldier by Alf-Marty / https://pixabay.com/illustrations/soldier-2335939/
Pixabay
Figure 5.5 Transforming Woman Hai Great White https://pixabay.com/photos/woman-hai-great
the nightmare Shark by SarahRichterArt / -white-shark-2435605/
Pixabay
Figure 5.6a Virtual reality Virtual Reality Goggles https://flic.kr/p/R6c8qU
goggles by Alvin Trusty /
CC BY-NC 2.0
Figure 5.6b Maze Maze by Aaron Webb / CC https://www.flickr.com/photos/68009656@N00/
BY-NC-SA 2.0 15006172613
Figure 5.7 Frankenstein Frankenstein by Special https://flic.kr/p/azeNWF
Collections at John
Hopkins University /
CC BY-NC-ND 2.0
Figure 5.8 Madam C. J. Madam C.J. Walker by https://simple.wikipedia.org/wiki/Madam_C._J.
Walker Scurlock Studio / CC0 1.0 _Walker#/media/File:Madame_CJ_Walker.gif
Figure 5.9 Facial Sheryl Shook Collection by https://drive.google.com/file/d/
expressions Sheryl Shook / CC0 1.0 1yZoKPJnl8UjULx4PEJTkNXloMD1wDcVm/view
Figure 5.10 The pons is Collage by Jason Ford using https://drive.google.com/file/d/
highlighted in red. Pons by Was a bee / CC 18XZUi5FBrRoFbt9ThoFTGNjfB27ueDrF/view?usp
BY-SA 2.1 JP and Happy- =sharing
Cat by Miss Nixie / CC
BY-NC-ND 2.0
Figure 5.11 In the MRI In the MRI by chezsterno / https://www.flickr.com/photos/chezsterno/
CC BY-NC-SA 2.0 158369167/in/photolist-eZFCT
Figure 5.12 Ventromedial Ventromedial prefrontal https://commons.wikimedia.org/wiki/File:
prefrontal cortex cortex by Finereach~ Ventromedial_prefrontal_cortex.png
commonswiki / CC BY 3.0
 124 • Image Credits

Image caption Attribution phrase Source/link

Figure 5.13 Motor and Motor and Sensory Regions https://commons.wikimedia.org/wiki/File:Blausen
sensory regions of the of the Cerebral Cortex by _0102_Brain_Motor%26Sensory.png
cerebral cortex BruceBlaus / CC BY 3.0
Figure 5.14 Mesopotamia Map of Mesopotamia by https://commons.wikimedia.org/wiki/File:N
Goran tek-en / CC -Mesopotamia_and_Syria_english.svg
BY-SA 4.0
Figure 5.15 Green sea turtle Green Sea Turtle by Brocken https://en.m.wikipedia.org/wiki/Green_sea_turtle
Ingalory / CC BY 3.0 #/media/File%3AGreen_turtle_swimming_over
_coral_reefs_in_Kona.jpg
Figure 5.16 Temple of Isis Temple of Isis, Philae by https://www.flickr.com/photos/15164743@N05/
Zolakoma / CC BY 2.0 2774331481
Figure 5.17 The wave The Wave by Marcel https://flic.kr/p/6W6Cqv
Lamieux / CC BY-NC 2.0
Figure 5.18 Stretching Ladies stretch circle by https://www.piqsels.com/en/public-domain-photo
together before the piqsels.com / CC0 1.0 -zknfq
discussion
Figure 6.1 Mouth and Mouth and pharynx by https://commons.wikimedia.org/wiki/File:Mouth
pharynx BruceBlaus / CC BY 3.0 _and_pharynx.png
Video 7.3.2 What causes What Causes Snoring https://youtu.be/inmop4Kv8PI
snoring and obstructive and Obstructive Sleep
sleep apnea? Apnea? by Capital
Otolaryngology Head
and Neck Surgeons / All
rights reserved
Figure 6.2 Continuous Using a CPAP by Soozie https://flic.kr/p/SpAHe7
positive airway pressure Bea / CC BY-SA 2.0
(CPAP) consists of a piece
that goes over the mouth
and/or nose.
Figure 6.3 Hā Breath Drawing 2 by Malia https://drive.google.com/file/d/
Hasegawa / CC BY 4.0 1WuAXMvsX1bahEhfWDsd40gdTfg3SWxnA/
view
Figure 6.4 Back to sleep Baby in Grey Onesie Lying https://unsplash.com/photos/jY61RtmjCdY
in Bed by Reynardo
Etenia Wongso /
Unsplash
Figure 6.5 Stretching Yoga by Jaime Fok / CC https://flic.kr/p/fsK56b
BY-NC-ND 2.0
Figure 6.6 Sleep paralysis The Nightmare by John https://commons.wikimedia.org/wiki/Johann
hallucination Henry Fuseli / CC0 1.0 _Heinrich_F%C3%BCssli#/media/File:John
_Henry_Fuseli_-_The_Nightmare.JPG
Figure 6.7 Falling asleep Falling to Sleep by https://flic.kr/p/hdLRV9
Shena Tschofen / CC
BY-NC-ND 2.0
 Image Credits • 125

Image caption Attribution phrase Source/link

Figure 6.8 Midnight snack Boy in white and black tank https://unsplash.com/photos/eYzg_aaTkcU
top by Chander Mohan /
Unsplash
Figure 6.9 Sleepwalking A Photography Of A Man https://www.pexels.com/photo/a-photography-of-a
can be dangerous. Standing On A Tree by -man-standing-on-a-tree-3680219/
Lukas Rodrigues / Pexels
Figure 6.10 Nightmares Spook by Mysticsartdesign / https://pixabay.com/photos/ghosts-gespenter
Pixabay -spooky-horror-572038/
Figure 6.11 Can’t sleep cant sleep by you me / https://flic.kr/p/dksYr5
CC BY 2.0
Figure 6.12a Owl Owl Animal Bird by https://pixabay.com/vectors/owl-animal-bird
OpenClipart-Vectors / -flowers-funny-158408/
Pixabay
Figure 6.12b Lark Meadowlark Bird Lark https://pixabay.com/vectors/meadowlark-bird-lark
by Clker-free-vector- -wings-stump-46453/
images / Pixabay
Figure 7.1 Sleepy driving Car keys with glass of https://www.flickr.com/photos/64000826@N08/
causes as many deaths as whiskey on table by 49173258126
drunk driving. Fort George G. Meade /
CC BY 2.0
Figure 7.2 Sleep debt by Sleep Debt Graph by Jason https://drive.google.com/file/d/
country Ford / CC0 1.0 1tZ9PZMNo1gg2sP88qNczFjc9ba3E2Jn3/view?usp
=sharing
Figure 7.3 US Capitol Capitol by Pierre-Selim / https://flic.kr/p/cvDgNJ
CC BY-SA 2.0
Figure 7.4 One race: The photomontage by geralt / https://pixabay.com/illustrations/photomontage
human race Pixabay -faces-photo-album-577022/
Figure 7.5 Kapu Aloha. Find Kapu Aloha by H. Doug https://flic.kr/p/uSKdaS
your cause and speak out! Matsuokoa / CC BY 2.0
Figure 7.6 Hawai‘i standing Hawaii Standing With https://flic.kr/p/MeKKbv
with Standing Rock Standing Rock #NoDAPL!
#NoDAPL by 340.org / CC BY-
NC-SA 2.0
Figure 7.7 Nap pod Google nap pod by https://flic.kr/p/4SENv5
Crystal Calderon /
CC BY-NC-ND 2.0
Figure 7.8 Sleeping in class sleepin in class by Jake / CC https://flic.kr/p/E8Mz7
BY-SA 2.0
Figure 7.9 Golden Gate Golden Gate Bridge during https://unsplash.com/photos/gZXx8lKAb7Y
Bridge, San Francisco, daytime by Maarten van
California den Heuvel / Unsplash
Figure 7.10 Zombies Action by Tan Cundrawan / https://pixabay.com/illustrations/action-active
Pixabay -activity-actor-2483679/
 126 • Image Credits

Image caption Attribution phrase Source/link

Figure 7.11 Wana (sea Wana Education by NPS https://www.nps.gov/articles/000/hoonau-mooolelo
urchin) are a source of Photo / CC0 1.0 .htm
healing food in Hawai‘i.
Figure 7.12 Physicians have Infermeiro—Saúde by https://unsplash.com/photos/M4Xloxsg0Gw
the potential to play Francisco Venâncio /
a critical role in sleep Unsplash
wellness.
Figure 7.13 MedGlobal MedGlobal Volunteer https://www.flickr.com/photos/182915307@N07/
volunteer performs Performs Surgery at 48649138206
surgery at Al-Shifa Al-Shifa Hospital in the
hospital in Gaza Strip Gaza Strip by MedGlobal /
CC BY-NC-ND 2.0
Figure 7.14 Start a sleep Men’s Gray Crew Neck Shirt https://www.pexels.com/photo/men-s-gray-crew
wellness conversation at by Thgusstavo Santana / -neck-shirt-1804638/
the barbershop. Pexels
Cover photo: Poppies, Poppies, lupine, and https://unsplash.com/photos/cmKQWcKWKxE
lupine, and bluebells bluebells create carpets
create carpets of color of color in California
in California during the during the spring by Jack
spring. Prichett / Unsplash