22

REVIEW ARTICLE

The reality of dreams

Niranjan Babu A, Lakshmi Ranganathan, Nagarajan
Ramakrishnan
Nithra Institute of Sleep Sciences, Chennai, Tamil Nadu, India.
○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○

DOI No:10.5958/0974-0155.2015.00003.0 Indian J Sleep Med 2015; 10.1, 22-28

Abstract
A series of images, ideas, emotions, and sensations that happen involuntarily in the mind at
the time of sleep are known as dreams. A definite understanding of the content and purpose
of dreams is not yet established. They have frequently been a subject of scientific assumption
and a focus of philosophical and religious interest.
Although there are several studies on dreams, there is no concrete evidence or explanation
on purpose, occurrence, or consistency. The objective of this article is to review available
literature on dreams with a specific focus on the character, content, and types of dreams.
Keywords: dreams, sleep, dream recall, memory, lucid dreams, REM and NREM.

Introduction Ancient Indian Upanishads consider dreams as a

third state, the other two being wakefulness and sleep.

O
neirology refers to the scientific study of dreams. Greek and Mesopotamians considered dreams to be
Dreaming is a state featured by sensory, messages from God or from the dead. Sigmund Freud,
cognitive, and emotional incidences during father of psychoanalysis, regards dreams as manifestations
sleep. Dreams usually occur 3-6 times per night and of deepest desires and anxieties, often relating to
lasts for 5-20 min. It has been shown that nearly 95% of repressed childhood memories or obsessions4. Carl Jung,
dreams are forgotten and only 48% of people who appear the founder of analytical psychology, expanded on Freud’s
in a dream are identified by the person dreaming1-2. idea that dream content relates to the dreamer’s
It was earlier believed that dreams occur only during unconscious desires5. Neurologists and neuroscientists
rapid eye movement (REM) stage of sleep. However, it explain dreams through different theories such as
is now understood that dreams may occur at other stages excitation of long-term memoriesor strengthening of
as well but are more likely to be recalled when they occur semantic memories6-17.
during REM sleep3. Although there are many beliefs, theories and studies,
○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○
there is no concrete evidence or explanation on purpose,
Address for correspondence occurrence, or consistency of dreams. We aim to explore
Dr. Nagarajan Ramakrishnan the literature to summarize the current concepts on
Director dream with a specific focus on character, content, and
Nithra Institute of Sleep Sciences, types.
Door # 29, Plot # 1997, J Block, 13th Main Road,
Anna Nagar, Chennai 600 040,
Tamil Nadu, India
Email: ram@nithra.com

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015

Niranjan Babu A, Lakshmi Ranganathan, Nagarajan Ramakrishnan 23

Materials andMethods contained physical violence, circumstances that were

stranger, emotionally strong, more failures, and
Literature search was performed in PUBMED using the unfortunate conclusions; 35% of these nightmares
keyword “dreams” through August 2015. The search featured chief emotions other than fear. Bad dreams often
revealed around 8,046 articles. The search was narrowed contained interpersonal fights and 55% of these dreams
by selecting only those that focus on character, content, featured major emotions other than fear.
and types of dreams in keeping with the objectives of
this article, and 51articles were selected for further Erlacher et al. studied the dreams of 840 German
detailed review.Abstracts were also included for review. athletes from various sports21. It was found in this study
However, studies on neuroanalysis, psychoanalysis, and that about 15% of the athletes experienced at least one
autobiographical memory concepts of dream were not upsetting dream previous toa significant competition or
included. game. A nearly equal number of athletes revealed at least
one upsetting dream in their sports profession. Athletic
failures were often related to reported dream content.
Themes in Dreams
Dreams with same content reported bymostof the Recurrent dreams
dreamers refer to typical dreams. The frequencies of A recurrent dream is one that repeats and occurs on a
typical dream themes have been studied by Ciric P et regular basis during sleep.A studyof 212 recurrent dreams
al., and the study indicated thatthere were 55 typical by Zadra et al22. showed that one or more threats were
dream themes, which were same over different sample observed in 66% of these dreams. The threats seemed
populations 18. There are 12themes that have been to be hazardous and targeted at the dreamer, and the
identified as most common in dreams (Table 1)19. dreamer took the more usual and reasonable defensive
action to face the threat. Less than 15% of the repeated
Table 1: Common themes in dreaming dreams showed realistic and or likely circumstances that
were dangerous for survival or reproductive success, but
• Falling
when dreaming, these dreamers were rarely successful
• Teeth falling out to evade the situation.The study also showed that
• Showing to work or school naked repeated dreams in adults were related to poor
psychological well-being and proposed that children
• Taking a test recording repeated dreams are also probable to
• Dying revealworse psychosocial adjustment than children
without repeateddreams.
• Meeting a celebrity
• Being chased Lucid dreams
• Partner cheating A dream in which the dreamer is aware of the dreaming
• Showing up late to a meeting state is deemed to be a lucid dream. Research has revealed
that lucid dreaming is associated with an enhanced
• Flying activation of parts of the brain that are typically repressed
• Being pregnant during sleep.

• Driving in an out of control vehicle A German study has shown that there is a significant
increase in the brain activity during the lucid dreaming
state. The authors found that there was an intensified
Types of Dreams activity in the frontal and fronto lateral parts of the brain,
which are the places of language thought and higher
Nightmares mental functions related to self-awareness. This supports
The contents of 9,796 dream reports were collected and the concept that lucid dreaming is an exclusive state of
studied by Pilon M et al., 20 which revealed 253 consciousness distinct from any other mental states.
nightmares and 431 bad dreams. Nightmares often

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015

24 The reality of dreams

Patients with narcolepsy have been shown to have The findings of Nielsen et al. are constant with the
higher rates of lucid dreaming than general population probability that processing memories into dream
and they also have high rate of dream recall23. integration takes around 7 days and this in turn helps
memory consolidation27.
Day dreams and nap dreams
Carrand Nielson24 studied daytime nap dreams (REM Colors in Dreams
and non-REM [NREM]) and compared these with each
A study by Okada H et al28 showed that about 80% of
other and with day dreams. Fifty-one subjects underwent
subjects younger than 30 years dreamt in color whereas
daytime naps (with REM or NREM awakenings) and
only 20% subjects elder than 60 years said they dreamt
furnished both waking day dream and nap dream
in color. The number of people in their 20s, 30s, and
records. Increased recall rates for REM (96%) and
40s dreaming in color increased from 1993 to 2009.
NREM (89%) naps were shown when compared with
Investigators speculate that there might be a role of color
representative recall rates for night time dreams (80%
television in this difference.
and 43%, respectively), suggestive of an increased
circadian effect. REM dreams showed higher rate of Another research by Murzyn E 29 involving both
emotional intensity and sensory experience compared questionnaires and dream diaries showed that older adults
with NREM dreams. experienced more black and white dreams than the
younger subjects. Older people stated that they
experienced brightness in both their color and black and
Characters in Dreams
white dreams equally. However, younger subjects
A study by Kahn et al. on 320 adults showed that 48% reported that their black and white dreams were of worse
of characters seen in dreams signified a named person quality.
who the dreamer aware of, 35% of characters were
recognized by their social role, and 16% were Characteristics of Dreams in General
unidentified25. Among named characters, characters Population
were identified by appearance (32%), behavior (21%),
face (45%), and just knowing (44%). Features of Age
bizarreness were observed in 14% of named and generic
characters. The study also examined the connection Aging is often associated with changes in sleep timing,
between dream emotion and dream character structure, and electroencephalographic activity. Scientific
identification. Affection and happiness were generally work approves that dream memory gradually decreases
linked with known characters and aided in recognizing from the commencement of adulthood and that dream
them even when these emotional characteristics were reports become less powerful with age. This development
varying with those of the waking state. happens quicker in men than women, and gender
variations in the content of dreams have also been
recorded30.
Memory of Dreams
Gender
Memories of day today activities sometimes incorporate
into dreams. A study by Fischer et al. has shown that A study by Rubinstein and Krippner, with 108 male and
REM sleep might counteract the intentional suppression 110 female participants, found no differences between
of memories, which makes them more accessible for the content of dreams between the two groups-specifically
recovery26. Two types of temporal effects have been in terms of aggression, friendliness, sexuality, characters,
shown to characterize the incorporation of memories weapons, or clothes that featured in their dreams.
into dreams. These include the day-residue effect, However, women’s dreams were characterized by
involving incorporations of events from the preceding increased number of family members, babies, children,
day, and the dream-lag effect, involving incorporations and indoor surroundings than men.31
delayed by about a week.

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015

Niranjan Babu A, Lakshmi Ranganathan, Nagarajan Ramakrishnan 25

Dreams in children consecutive mornings during their first week of

hospitalization. The results found were 39% of patients
Kessels32 in his study investigated anxiety dreams in 103 reported pain dreams, of which 30% was only totally
children aged 9-11 years and recorded that girls revealed pain related. These patients revealed evidences of poor
an increased incidence of anxiety dreams than boys, sleep, increased nightmares, intense pain during
although they could not recollect their dreams more often. therapeutic procedures, and higher consumption of
The frequency of dreams was more in girls than boys anxiolytic medication. More than half of the patients
and featured about the loss of another person, falling, of did not record pain dreams; however, these results were
socially worrying conditions and small animals, animals suggestive that pain dreams happen at a higher incidence
as attackers, family members (mainly siblings), and other in suffering populations than in normal participants37.
female subjects of known identity.
Dreams in depression
Muris P et al33 showed that Fear (75.8%), worries
(67.4%), and scary dreams (80.5%) were the anxiety In a study by Firth et al, The dream content of psychiatric
symptoms note in a study comprising 190 normal school in-patients who were admitted because of suicidal
children aged 4-12 years. Anxiety of scary dreams was attempts were compared with three inpatient control
generally observed in children aged 4-6 years, which groups who were admitted for (i) depression and suicidal
dominated even more higher in children aged 7-9 years, ideation without attempt, (ii) depression with no suicidal
but their incidence reduced in children aged 10-12 ideation, and (iii) commission of a violent act without
years.Variations in categories of fears, worries, and suicide.
dreams were observed across age groups, with fears and
Results of the study showed that both suicidal and
scary dreams relating to imaginary creatures reducing
violent patients revealed higher death content and
with age and worries about test performance increasing
damaging violence in their dreams.This was a function
with age.
of the severity of depression and few character
Dreams in pregnancy personalities, such as impulsivity, and not particular to
the patient’s behavior itself38.
Studies done by Lara-Carrasco et al., comparing the
dreams of pregnant and nonpregnant women,34,35 have A study by Marinova et al. on 52 inpatients
shown that pregnant group experienced more dreams experiencing depression revealed that depressed patients
with the theme relating to pregnancy, childbirth, and with nightmares showed considerably increased risk of
fetus. Childbirth theme was more observed in late than suicide. Depression seemed to be a risk factor for suicidal
in early third trimester. Pregnant women experienced behavior when associated with nightmares39.
more morbid elements in their dreams than the non
Dreams in bereavement
pregnant group.
In the study by Wright et al. on 278 bereaved
individuals,40 it was noted that 58% of participants
Dreams in Specific Patient Groups revealed dreams of their dead loved ones, with variable
levels of incidences. Majority of the revealed that their
Dreams in migraine
dreams were either enjoyable or both enjoyable and
In a study that evaluated dreams in people experiencing worrying, and few recorded entirely disturbing dreams.
various types of headaches, it was found that people with Predominant dream contents comprised enjoyable
migraine revealed higher incidences of taste- and smell- memories or experiences, the deceased free of illness,
related dreams, suggesting there could be involvement remembrances of the deceased’s illness or death time,
of cerebral structures, such as amygdala and the deceased in the life after death appearing relaxed
hypothalamus, in migraine mechanisms and in the and at peace, and the deceased communicating a message.
biology of sleep and dreaming36. Sixty percentage of subjects felt that their dreams
impacted their grief process.
Dreams in pain
In a study by Raymond et al., 28 non ventilated burn
victims were questioned about their dreams for five

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015

26 The reality of dreams

Factors That Influence Dreams REM and NREM sleeps experience dreaming, dreams
recorded from these periods vary considerably in both
Sleep disorders quality and quantity and are likely to be formed by various
processes.
According to the review article by Schredl, dream recall
is more in patients with insomnia, and their dreams In another study, visual imagery was recorded more
reflected the stress pertaining to their condition, but, in frequently, after arousals from REM compared with stage
sleep apnea patients, this is rare. Patients with narcolepsy 2 sleep; 83% of REM arousals compared with only 34%
were shown to have more bizarre and negatively toned stage 2 arousals occasioned in imagery reports46.
dreams41. Cortisol is also proposed to play a vital role in
In another study, researchers showed that, in a test governing the memory systems’ states during sleep. High
group of 393 subjects, 71.4% patients without sleep levels of cortisol, observed during REM sleep, disrupt
apnea were able to recollect their dreams, but those with normal hippocampal to neocortical communication,
severe obstructive sleep apnea revealed a significantly which interferes with the form of memory consolidation,
reduced incidence of dream recall. The study results also and, hence, the content of dreams is also affected47.
showed that patients with sleep apnea could not recall
their nightmares42. Recalling Dreams
Medications Dream investigators determine that about 95% of all
Clinical knowledge and a few published studies have dreams are disremembered completely upon awakening.
reported that selective serotonin reuptake inhibitors Occasionally, a dream is unexpectedly recalled later in
(SSRIs) strengthen dreaming. Tribl et al. reviewed 21 the day or on another day, suggestive that the memory is
clinical studies and 25 case reports on the effect of not completely lost but, for some cause, it may have
antidepressants on dreaming43. The review showed that been problematic to remember48.
tricyclic antidepressants induced more positive dream In a French study,49 researchers performed brain scans
emotions. In both depressed patients and healthy on 41 people both when awake and during sleep. Of the
volunteers, there was a decrease of dream recall frequency subjects, 21 recollected dreams about five mornings per
with antidepressant use. Nightmares were caused by week and were categorized as “high dream recallers,”
withdrawal from tricyclic antidepressants and while the remaining 20 recalled dreams only two
monoamine oxidase inhibitors, phenelzine and mornings per month and were categorized as “low dream
tranylcypromine, while intensified dreams were reported recallers.” During both asleep and awake, the high dream
after withdrawal of SSRIs/serotonin-norepinephrine recallers revealed enhanced levels of activity in the brain’s
reuptake inhibitors. medial prefrontal cortex and temporoparietal junction.
Alcohol Brain lesion and neuroimaging findings unite in
demonstrating that the temporo-parieto-occipital junction
A study by Steinig et al., which examined the sleep quality and ventromesial prefrontal cortex play vitalroles in dream
and the subjective dream experience in alcohol-dependent remembrance.
patients during withdrawal and self-denial compared with
healthy control subjects, found that patients with alcohol
dependency during withdrawal and self-denial dreamt Conclusion
considerably more frequently about alcohol. Subjective Dream research remains a challenge, and current
sleep and dream quality is highly impaired in patients evidence is limited. Dreams occur in all stages of sleep;
with alcohol dependency44. but, those that occur during REM sleep are more likely
to be recalled. Age, gender, and sleep disorders are
Dreams and Stages of Sleep common factors that affect dreams. Sleep-related
disorders such as narcolepsy lead to negatively toned
One study by Takeuchi et al45. hypothesized that various dreams and lucid dreams. Available literature shows that
physiological processes trigger dreaming during REM there is a connecting link between real-life events and
and NREM sleeps. They concluded that although both dreams.

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015

Niranjan Babu A, Lakshmi Ranganathan, Nagarajan Ramakrishnan 27

References 22. Zadra A, Desjardin S, Marcotte E. Evolutionary function of

dreams: a test of the threat simulation theory in recurrent
1. The American Heritage Dictionary of the English Language, dreams.Conscious Cogn 2006;15:420-63.
4th ed. Boston, MA: Houghton Mifflin Hartcourt; 2000. 23. Dodet P, Chavez M, Leu-Semenescu S, Golmard JL,
RetrievedMay 7,2009. ArnulfI.Lucid dreaming in narcolepsy.Sleep 2015;38:
2. Kavanau JL. Sleep, memory maintenance, and mental 487-97.
disorders.J Neuropsychiatry ClinNeurosci2000;12: 24. Carr M, Nielsen T. Day dreams and nap dreams: content
199-208. comparisons. ConsciousCogn. 2015;6:196–205.
3. Hobson JA. REM sleep and dreaming: towards a theory of 25. Kahn D, Stickgold R, Pace-Schott EF, Hobson JA. Dreaming
protoconsciousness. Nat Rev Neurosci2009;10:803-13. and waking consciousness: a character recognition study.
4. Freud S The Interpretation of Dreams (1900) JSleep Res 2009;9:317-25.

5. Jung:London: Hogarth Press; 1964, p. 21. 26. Fischer S, Diekelmann S, Born J. Sleep’s role in the
processing of unwanted memories. J Sleep Res
6. Tsoukalas I. The origin of REM sleep: A hypothesis. 2011;20:267-74.
Dreaming 2012;22:253-83.
27. Nielsen TA, Kuiken D, Alain G, Stenstrom P, Powell RA.
7. Vitelli R. Exploring the mystery of REM sleep. Psychology Immediate and delayed incorporations of events into
Today, Online blog, March 25, 2013. dreams: further replication and implications for dream
function. JSleep Res 2004;13:327-36.
8. Solms M. Dreaming and REM sleep are controlled by
different brain mechanisms. Behav Brain Sci. 2000;23: 28. Okada H, Matsuoka K, Takao H. Life span differences in
843-50. color dreaming. Dreaming 2011;21:213-20.
9. Zhang J. Memory process and the function of sleep. J 29. Murzyn E. Do we only dream in colour? A comparison of
Theoret2004;6:1-7. reported dream colour in younger and older adults with
different experiences of black and white media. Conscious
10. Zhang J. Continual-activation theory of dreaming. Dynam
Cogn 2008;17:1228–37.
Psychol2005. Retrieved March 13, 2006.
30. Guénolé F, MarcaggiG, Baleyte JM, Garma L. [Dreams in
11. Tarnow E. How dreams and memory may be related.
normal and pathological aging]. PsycholNeuropsychiatr Vieil
Neuro-Psychoanalysis 2003;5:1-12.
2010;8:87–96.
12. The Health Benefits of Dreams. Available at: Webmd.com.
31. Rubinstein K, Krippner S.Gender differences and
February 25, 2009. RetrievedAugust11,2012.
geographical differences in content from dreams elicited
13. Stickgold R, Hobson JA, Fosse R, Fosse M. Sleep, learning, by a television announcement.Int JPsychosom 1991;38:40–4.
and dreams: off-line memory reprocessing. Science2001;
32. Kessels T. Fear in dreams of 9- to 11-year-old children.
294 (5544):1052-7.
Prax Kinderpsychol Kinderpsychiatr 2004;53:19–38.
14. Payne JD, Nadel L. Sleep, dreams, and memory
33. Muris P, Merckelbach H, Gadet B, Moulaert V.Fears, worries,
consolidation: the role of the stress hormone cortisol.Learn
and scary dreams in 4- to 12-year-old children: their
Mem2004;11:671-8.
content, developmental pattern, and origins.J ClinChild
15. Robert W. Der Traumals Naturnothwendigkeiterklärt. Psychol 2000;29:43–52.
Zweite Auflage, Hamburg: Seippel; 1886.
34. Lara-Carrasco J, Simard V, Saint-Onge K, Lamoureux-
16. Evans C, Newman E. Dreaming: an analogy from Tremblay V, Nielsen T.Maternal representations in the
computers.New Scientist1964;419:577-9. dreams of pregnant women: a prospective comparative
study.Front Psychol 2013;4:551.
17. Crick F,Mitchison G. The function of dream
sleep.Nature1983;304:111-4. 35. Dagan Y, Lapidot A, Einsentein M.Women’s dreams reported
during first pregnancy.Psychiatry ClinNeurosci
18. Ciric P, Schredl M, Götz S, Wittmann L. Typical dreams: 2001;55:13–20.
stability and gender differences.JPsychol 2004;138:
485-94. 36. Lovati C, DeAngeli F, D’Amico F, et al.Isthe brain of
migraineurs”different” even in dreams?NeurolSci
19. Wallace I. The Dr. Oz Showand Anderson Cooper 360. 2014;35Suppl 1: 167–9.
Grant R.The Complete A to Z Dictionary of Dreams.
Lawrence L. The Illustrated Dream Dictionary.New York 37. Raymond I, Nielsen TA, Lavigne G, Choinèire M.
Daily. Newscolumn on dream analysis. Incorporation of pain in dreams of hospitalized burn
victims.Sleep 2002;25:765–70.
20. Pilon M, Zadra, Donderi DC. Variety and intensity of
emotions in nightmares and bad dreams.JNervMentDis 38. Firth ST, Blouin J, Natarajan C, Blouin A. In comparison of
2006;194:249-54. the manifest content in dreams of suicidal, depressed and
violent patients.Can JPsychiatry 1986;31:48–53.
21. Erlacher D, Ehrlenspiel F, Schredl M. Frequency of
nightmares and gender significantly predict distressing 39. Marinova P, Koychev I, Laleva L, et al. Nightmares and
dreams of German athletes before competitions or suicide: predicting risk in depression.PsychiatrDanub
games.JPsychol 2011;145:331-42. 2014;26:159-64.

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015

28 The reality of dreams

40. Wright ST, Kerr CW, Doroszczuk NM, Kuszczak SM, Hang 45. Takeuchi T, Miyasita A, Inugami M, Yamamoto Y. Intrinsic
PC, Luczkiewicz DL. The impact of dreams of the deceased dreams are not produced without REM sleep mechanisms:
on bereavement: a survey of hospice caregivers. Am JHosp evidence through elicitation of sleep onset REM periods.
Palliat Care 2014;31:132–8. JSleep Res 2001;10:43–52.
41. Schredl M. Dreams in patients with sleep disorders. Sleep 46. Conduit R, Crewther SG, Coleman G. Spontaneous eyelid
Med Rev 2009;13:215–21. movements (ELMS) during sleep are related to dream recall
on awakening. JSleep Res 2004;13:137–44.
42. Pagel JF, Kwiatkowski C. The nightmares of sleep apnea:
nightmare frequency declines with increasing apnea 47. Payne JD, Nadel L.Sleep, dreams, and memory
hypopnea index. J Clin Sleep Med 2010;6:69–73. consolidation: the role of the stress hormone cortisol. Learn
Mem 2004;11:671–8.
43. Tribl GG, Wetter TC, Schredl M. Dreaming under
antidepressants: a systematic review on evidence in 48. International Association for the Study of Dreams,
depressive patients and healthy volunteers. Sleep Med RetrievedOctober 21, 2014.
Rev2013;17:133–42.
49. French National Institute of Health and Medical Research
44. Steinig J, Foraita R, Happe S, Heinze M. Perception of sleep (INSERM), News release, February 12, 2014.
and dreams in alcohol-dependent patients during
detoxication and abstinence.Alcohol Alcohol
2011;46:143–7.

Indian Journal of Sleep Medicine (IJSM), Vol. 10, No. 1, 2015