How Many Continents Does Katy Perry's "Roar" Video Take Place On Simultaneously?

The video for Katy Perry's newest single, "Roar," has been viewed almost 36 million times since it appeared online four days ago. In case none of those views were yours, a quick plot summary: A woman crash-lands in the jungle with an attractive but inconsiderate boyfriend in safari gear who's eaten by a tiger at 0:40. She's scared at first, but soon befriends a monkey, is bathed by a helpful elephant, and changes out of her old clothes into (spoiler alert!) a leopard bra. And sings.

On her road to empowerment, Katy gets help from a diverse array of animals. So diverse, in fact, that their being together in the jungle might be the most fantastical element of the video.

First there's the monkey, seen above inspiring Katy to turn her stiletto* into a spear. It's a capuchin, native to Central and South America.

What about the beast that disposed of the boyfriend? Katy sings "I've got the eye of the tiger," and she's got the whole body of it in her video. But tigers live only in Asia, so either the big cat or the monkey seems to have taken a wrong turn across an ocean somewhere.

Elephants can live in Asia as well, so maybe Katy's pachyderm friend (who does double duty as shower head and clothes hook) is in the right place. Asian elephants, though, have distinctively small ears that sit low on their heads. The fellows with the big flapping ears—on full display in the picture at the bottom of this page—are African elephants.

So now we're up to three landmasses at once. Perhaps this bird can settle the tie: it looks like a great hornbill, a tropical bird from Asia.

Then there's the creature whose teeth Katy is brushing in this scene. Its short and rounded snout, unlike a crocodile's long, pointed one, suggests it's an alligator. That's one more point for the Americas. (A crocodile's bottom teeth also protrude when its mouth is closed, while a gator's don't. But this prop only appears in the video with its mouth wide open. It may not have a hinge.) 

A crocodile would have given another point to Africa. Sorry, cradle of civilization! But wait—sneaking into the frame during the final seconds of the video is a baboon, a monkey that lives only in Africa (except for a desert-dwelling species in the southern tip of the Arabian Peninsula).

To break the three-way tie between continents, let's go back and take a closer look at the birds in the video. There are a couple of macaws, the striking parrots from Central and South America:

And key to the plot of the whole video is this red bird. Katy uses its feathers to build a lure that tempts the tiger, which she ultimately subdues in a roar-off and turns into her pet.

The red bird also provides a plot twist for our purposes. I sent the picture to ornithologist and Guardian blogger GrrlScientist for identification. "Oh wow," she wrote back, "a female eclectus parrot." The males are bright green with orange beaks, looking like a different species altogether. Eclectus parrots don't live alongside the capuchin, the elephant, or the tiger: they're native to northeastern Australia, New Guinea, and neighboring islands.

At least four parts of the world, then, are represented in Katy's jungle. (Don't worry about the leopard bra—our heroine fashioned it out of a scarf she was wearing on the plane.) It's a little surprising not to see a lion in the video, since it's the only animal aside from the tiger that actually appears in the song's lyrics. But then again, lions prefer the savanna to the forest. Maybe that would have been too unrealistic.

*I'm not sure of the species of shoe.


Images: screenshots from "Katy Perry - Roar."

On the Road with the Shambulance

Hello from the land of boxes!

I'm about to move across the country, so there will be a brief hiatus from new stories here. But in the meantime, please enjoy some travel-themed reruns.

The Shambulance is a vehicle with an identity crisis (it might travel by land, sea, or space, and is potentially horse-drawn). It's also a series on this blog examining dubious health fads. Below, you'll find its complete voyages.

It has been, I think you'll agree, a twisted journey.

* * * * * * * * * * * * * * *

Ionic Foot Detox Baths (June 2012)
Hint: Don't.

Ab Toning Belts (or, Muscle Tone Is All in Your Head) (July 2012)
This goofy infomercial product blew my mind. But not because it works.

Zero-Calorie Noodles? (August 2012)
The only Inkfish post ever to involve a taste test.

Infrared Body Wraps (September 2012)
Be glad this doesn't work.

5 Reasons Not to "Cleanse" Your Colon (October 2012)
#3: It's rude to firehose your friends.

Copying Roger Clemens Won't Help You Lose Holiday Pounds (November 2012)
The dirt on vitamin B12 shots.

Enough Already with the Juice Cleanses (January 2013)
In which a salesperson suggests I fast for five straight weeks.

Deer Antlers Are Not Unicorn Horns (February 2013)
Some professional athletes are confused about this.

Reflexology and Other Stories (April 2013)
Non-traditional non-Chinese medicine.

Laser Lipo Only Kind of Sucks (July 2013)
Surprisingly, the least sketchy place the Shambulance has traveled.

If you'd like to suggest a future destination for the Shambulance to drive, climb, dive, or teleport to, leave your suggestion in the comments!


Image: taken by me with my iPhone because we already packed the camera cord.

Fish Grow Big Fake Eyes When Predators Are Near

If you're a young, edible animal, a little flexibility about how you develop can save your behind. Or, if you're a damselfish, it can get a few bites taken out of your behind but ultimately save your life.

The damselfish Pomacentrus amboinensis lives on coral reefs in the western Pacific, where it spends its days nibbling algae and trying to avoid being swallowed. As juveniles, these small fish have a pronounced eyespot toward the back of their bodies—a cartoonish false eye drawn on the body, like you might see on a butterfly's wing. Normally, the eyespot fades as the fish matures.

Researchers from James Cook University in Australia and the University of Saskatchewan in Canada asked just how flexible damselfish are while those false eyes are fading away. Can fish opt to keep their false eyes in certain situations? And if they do, does this not-very-subtle disguise actually do anything to protect them?

The scientists raised damselfish in tanks divided into compartments. Some damselfish lived alongside a natural predator of theirs: Pseudochromis fuscus, the "dusky dottyback." Thanks to the special tanks' clear windows and shared water, the young damselfish could see and smell the predator all the time. Other damselfish were raised on their own, or in tanks shared with a harmless vegetarian fish.

After maturing for six weeks in their respective tanks, the fish showed some clear differences. Compared to the other fish, damselfish that had lived near predators had larger false eyes. And their real eyes—startlingly to the scientists—were actually smaller.

"I was very surprised by the result," says lead author Oona Lonnstedt, a PhD student at James Cook University. "It just goes to show the lengths small prey will go to minimize predator attention on their front end."

This assumes that the point of all this camouflaging—growing a big fake eye near your tail and minimizing the actual eyes on your face—is to focus predators' attention on the wrong end of your body. The researchers didn't test predatory fish to see which part of a damselfish they chomped down on. But they did put the damselfish from their experiment onto isolated reef patches in the wild to see how they fared.

Within two days, up to half of the control fish (those raised alone or with non-predators) had disappeared from the reefs, and were presumed eaten. Damselfish that had grown up in a tank with predators, though, radically outperformed the others. Four days after being released onto the reefs, 90% of them were still alive and well.

Their large eyespots and minimized eyes may have made predators chase their back end, where a bite isn't as fatal as one to the head. These fish had also grown up taller in the spine-to-belly dimension, which gives an added challenge to hunters limited by the size of their mouths (and may give the damselfish better bursts of speed too). In the lab, these fish were less active and spent more time hiding; their reticence may also have helped them survive in the wild.

There's a trade-off happening, Lonnstedt says. Damselfish that live with predators and grow large false eyes also have stunted eye growth, which probably impairs their vision. It's not bad enough, though, to keep them from avoiding predators on the reef. In the end, being flexible about how their bodies develop allows them to survive and swim another day.

Image: Lonnstedt et al. (The fish on top grew up in the predator tank.)

Lönnstedt OM, McCormick MI, & Chivers DP (2013). Predator-induced changes in the growth of eyes and false eyespots. Scientific reports, 3 PMID: 23887772

Swapping Bodies with a Child Makes Everything Seem Bigger

Remember revisiting your preschool or kindergarten classroom once you were older, and realizing all those tables and sinks that are normal-sized in your memory were actually miniature? And that the giant hill you used to struggle up is more of a mound? Adults can regain that feeling of living in an oversize world just by putting on a virtual-reality headset. (Large kid who used to budge you in line for the slide not included.)

This is the latest spinoff of the rubber-hand illusion, a phenomenon in which watching a rubber hand being stroked with a paintbrush, while you feel a matching sensation on your own hand, creates an eerie sensation that the rubber hand is your own. Another recent study found that kids experience the illusion more strongly than adults. Aside from being a neat party trick, the research may have implications for amputees who experience phantom limbs.

The illusion's newest incarnation, by Mel Slater at the University of Barcelona and others, didn't use any physical contact. Instead, subjects wore virtual-reality goggles that let them see through the eyes of a virtual body. The avatar's movements were matched to their own with motion tracking, and subjects could watch their virtual bodies in a mirror while they moved and stretched.

Although the virtual body matched a subject's movements, it didn't match his or her size. The avatars were all miniature people--either a child about four years old, or an adult scaled down to the same height.

With either kind of small body, subjects reported that they felt an illusion that the avatar's body was their own. Researchers quantified this by having subjects look at different-sized objects in the virtual world and hold out their hands to indicate how wide the objects were. (For this part of the experiment, they couldn't see their virtual hands.)

Size perception is always tied to the size of your own body, Slater says, so all subjects overestimated the size of the objects they saw. The same thing happened in an earlier rubber-hand study that had subjects inhabiting both tiny and giant bodies.

But with a child's body, the effect was significantly greater, the authors report in PNAS. People virtually inhabiting a four-year-old's body perceived objects as even larger than people inhabiting a small adult body did.

The authors think this may be because the experiment triggers specific, first-person memories of being in a child's body. Living in a miniature adult body, of course, is a less common experience. This is a "possible new discovery," Slater says—"that the brain codes for body type, not just for size."

Slater has experienced the illusion himself. "It is very powerful and strange to see yourself in a mirror as a small child," he says. Maybe stranger, even, than those tiny sinks.


Image: Slater et al. (from supplemental movie)

Domna Banakou, Raphaela Groten, & Mel Slater (2013). Illusory ownership of a virtual child body causes overestimation of object sizes and implicit attitude changes PNAS DOI: 10.1073/pnas.1306779110

Decapitated Worms Regrow Heads with Memories Still Inside

How good are you at remembering something you learned two weeks earlier? What if during the intervening 14 days, your head was removed? One flatworm isn't bothered by this scenario. After growing back its entire head and brain, it picks off pretty much where it left off.

The planarian is a modest little flatworm, the kind of common microscope denizen you might find in a Gary Larson cartoon. What's remarkable about it is its ability to regenerate. The whole body can regrow, head to eyespots to tail, from even a tiny fragment of the original animal.

Tal Shomrat and Michael Levin at Tufts University built a computerized apparatus for training planarians. Back in the 1960s, an intriguing line of research had suggested that the worms might be able to retain memories after decapitation. But researchers had done their training and testing by hand, a cumbersome method that led to inconsistent results. ("The process of training worms by hand is very time-consuming," Levin says, probably understating it.) Ultimately, the topic was abandoned. Now, with a totally automated procedure, Shomrat and Levin hoped to study planarian memory with less error and greater numbers of worms.

First, their worms spent 10 days getting familiar with one kind of environment, either a regular petri dish or one with a rough floor. They were fed abundantly so that they'd learn a positive association with their home environment. Then, for testing, they were put in a rough-bottomed dish with a little spot of food in the center and a light shining on it. Planarians like to stick to the periphery, and they hate light, so they needed to overcome both aversions to get the food. As expected, worms that were more familiar with the rough dishes reached the food sooner, as measured by video tracking.

When the researchers tested the worms again 14 days later, they found that the worms trained on a rough-bottomed dish were still more comfortable with it than the other worms. This memory seemed to last for at least two weeks. Perfect—that's just enough time for a planarian to lose its head and grow it back.

The worms were relieved of their heads. The scientists made certain that no bit of brain survived. Then, after the worm stumps had painstakingly re-headed themselves, the planarians went back into the testing chamber.

The memory wasn't there right away. But Levin and Shomrat found that if they gave all the worms one quick training session before testing, worms who'd previously been familiarized with rough petri dishes reached the food significantly faster than the other worms. The training session "basically allowed the worms to refresh their memory of what they had learned before decapitation," Levin says. In other words, their memories had survived the loss and regrowth of their heads.

Levin doesn't know how to explain this. He says epigenetics may play a role—modifications to an organism's DNA that dial certain genes up or down—"but this alone doesn't begin to explain it."

It's a mystery, Levin says, how a chemical tweak somewhere outside of a worm's brain can later be translated into information, such as the knowledge that a bumpy environment means food is nearby. "We don't have an answer to this," he says. "What we do show evidence of is the remarkable fact that memory seems to be stored outside the brain."


Image: Shomrat and Levin.

Tal Shomrat, & Michael Levin (2013). An automated training paradigm reveals long-term memory in planaria and its persistence through head regeneration The Journal of Experimental Biology : 10.1242/​jeb.087809

How to Detune Someone with Perfect Pitch

Granted, it's a prank you can play on only 1 in 10,000 people. But if you find one of those rare individuals who can name any note they hear, with just a brief manipulation you can set that power awry. You can later console your subject with a reminder that, after all, nobody's perfect.

A children's choir that I used to sing in always performed the carol "Once in Royal David's City" at a certain concert, and the boy soprano who sang the opening solo would be sent up to a high chapel balcony along with a man who had perfect pitch. The adult would hum the correct note in the boy's ear, apparently, so that he could begin the solo out of a dramatic silence. (Looking back, I'm not sure sending someone up to blow very softly on a pitch pipe wouldn't have accomplished the same thing—but the addition of the superpowered helper made the whole thing more thrilling.)

People with perfect, or absolute, pitch can identify any notes they hear, and can tell you if those notes are a little sharp or flat. Stephen Hedger, a graduate student at the University of Chicago who's studying both cognitive psychology and musicology, has perfect pitch. After discovering that his perception could be skewed distressingly by someone fiddling with a tuning knob while he played the keyboard, he decided to test just how absolute "absolute pitch" really is.

Hedger gathered 13 subjects who'd scored as high as possible on a test of absolute pitch. At the beginning of the experiment, they listened to a series of notes; for each one, subjects had to identify the name of the note and whether it was in tune. The notes included everything from middle C to the B above it, and each note had three versions: one in tune, one slightly flat, and one slightly sharp.

(The out-of-tune notes were off by 33 "cents." The distance between any two notes, say C to C#, is 100 cents. Most people can detect a difference of just 25 cents, so a 33-cent difference—a third of the way to the next note—would be comfortably noticeable to all but the tone-deaf.)

Next, subjects listened to the entirety of Brahms's Symphony No.1 in C minor. During the first movement, which is 15 minutes long, the recording ever so slowly went flat. The pitch crept downward at 2 cents a minute, ending a full 33 cents flat from the original. The remaining half-hour of the symphony was played in the new, flattened key. When asked, none of the subjects noticed said they noticed a difference in pitch.

Then subjects completed the pitch quiz a second time. Now, pitches that were flat sounded in-tune, and pitches that were in tune sounded a little out of tune. (The subjects still correctly identified sharp pitches.)

In a second experiment, instead of Brahms subjects heard a series of modern musical compositions that only include 5 pitches. Just as before, the music slowly drifted flat and then stayed that way. In the pitch quiz afterward, subjects misjudged all the flat and in-tune notes they heard—not only the five notes they'd listened to.

A brief time listening to out-of-tune notes was able to skew a person's whole internal scale. Yet when subjects heard test pitches played by an instrument they hadn't listened to during the experiment—for example, a set of piano notes after the Brahms symphony, which didn't include a piano—their judgements were correct again. It is "as if each instrument voice retains its own tuning," Hedger and his coauthors write in Psychological Science.

People with absolute pitch, those superpowered few, are thought to learn their pitches in childhood. The pitches aren't absolutely stable, though: the detuning study shows they can be bent and changed by music a person has recently heard.

In a video, senior study author Howard Nusbaum says that the group is now looking for ways to improve people's sense of pitch, rather than detuning it, by taking advantage of this flexibility. "We are constantly changing to meet the circumstances around us," he says. That means someday the rest of us may be a little more perfect.


Image: by Timothy Valentine (via Flickr)

Hedger, S., Heald, S., & Nusbaum, H. (2013). Absolute Pitch May Not Be So Absolute Psychological Science DOI: 10.1177/0956797612473310

The Shambulance: Reflexology and Other Stories

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. Helping me keep the Shambulance on course are Steven Swoap and Daniel Lynch, both biology professors at Williams College.

Sticking a Q-tip up one’s nose is not the source of many great insights. Yet it’s how an American doctor in the early 20th century developed the theory that became modern reflexology. He would be proud—though maybe a little confused—to see people today flocking to reflexology spas, where practitioners treat all their problems via the soles of their feet.

The American doctor in question was William H. Fitzgerald, an ear, nose and throat specialist. In a 1917 book, he explained the genesis of his big idea:

Six years ago I accidentally discovered that pressure with a cotton tipped probe on the muco-cutinous margin (where the skin joins the mucous membrane) of the nose gave an anesthetic result as though a cocaine solution had been applied . . . Also, that pressure exerted over any bony eminence of the hands, feet or over the joints, produces the same characteristic results in pain relief . . . This led to my ‘mapping out’ these various areas and their associated connections and also to noting the conditions influenced through them. This science I have named "Zone Therapy."

Chapter titles from Zone Therapy include "Zone Therapy for Women" (tongue depressor into the back of the throat for menstrual cramps), "Painless Childbirth" (rubber bands around the toes, among other interventions) and "Curing Lumbago with a Comb."

A nurse and physical therapist named Eunice D. Ingham extended the idea of zone therapy in the 1930s and 1940s, eventually mapping the entire body onto the soles of the feet. She called each important point on the foot a “reflex” because it reflected back to a certain organ or body part. Ingham wrote two books on the subject, now called reflexology: Stories the Feet Can Tell and Stories the Feet Have Told.

Today, the International Institute of Reflexology describes its practice as as “a science which deals with the principle that there are reflex areas in the feet and hands which correspond to all of the glands, organs and parts of the body.” Stimulating these points “can help many health problems in a natural way.” The site insists, “Reflexology…should not be confused with massage.”

There has been some confusion and blending, though, between Western reflexology and traditional Chinese medicine. Ingham and Fitzgerald's idea of "zones" is similar to the Chinese principle of "meridians." In traditional Chinese medicine, meridians are paths that carry qi through the body and connect the acupuncture points. Reflexology groups like to say that Fitzgerald "rediscovered" the science from more ancient roots. They even claim that ancient Egyptians practiced it, based on tomb paintings showing people holding each other's feet.

Whoever thought it up first, the idea that the soles of your feet hold a miniature map of the entire rest of your body defies a scientific explanation.

“The problem is communication,” says physiologist Steven Swoap. “How does the foot talk to the pancreas?”

The foot is full of sensory nerves, Swoap explains. These can detect temperature, pain or position and send that information to the spinal cord. If the signal is something urgent—say, you stepped on a nail—the spinal cord will send a quick command back to the foot (“STOP!”). If the signal from the foot is a non-painful one (“Hey, I’m walking on grass”), it will travel all the way up the spinal cord to the brain.

“But in no instance do those sensory nerves bypass either the spinal cord or the brain and go directly to the liver, or the kidney, or the colon,” Swoap says. This means your foot can’t communicate directly with any other body part except your spinal cord or brain. Whatever stories the feet have told, they’ve had a limited audience.

Daniel Lynch, a biochemist, points out that sex organs are missing from some reflexology maps. “Why aren’t the gonads on there?” he asks. Other maps label a "testes and ovaries" region around the middle of the heel, but there's variation from one chart to the next.

Setting aside the map itself, Lynch says, “Where is the evidence that it actually works?”

The evidence is slimmer than a stiletto heel. In a 2011 review paper, complementary medicine researchers at the Universities of Exeter and Plymouth dug up every scientific study of reflexology they could find. Out of 23 randomized clinical trials, only 8 “suggested positive effects.”

The quality of the studies was “variable,” the authors write, “but, in most cases, it was poor.” Only four studies that found a positive effect used a placebo control—that is, did massaging the feet without regard to “zones” give patients the same symptom relief? In general, studies tended to use small groups of subjects and not to be replicated by other researchers.

Reflexology has been tested on conditions including asthma, premenstrual syndrome, irritable bowel syndrome, multiple sclerosis, and back pain. If reflexology does have a benefit, “The most promising evidence seems to be in the realm of cancer palliation,” or making patients more comfortable, the authors write. Overall, though, they found no convincing evidence that reflexology has power beyond the placebo.

Not that we should thumb our Q-tip-free noses at the placebo effect. The body has an impressive power to make itself feel better based on our expectations. A foot rub from a professional may very well ease a person’s pain. If that professional says anything about zones, though, it’s only a story.


Image: Foot reflexology chart by Stacy Simone (Wikipedia)

Ernst, E., Posadzki, P., & Lee, M. (2011). Reflexology: An update of a systematic review of randomised clinical trials Maturitas, 68 (2), 116-120 DOI: 10.1016/j.maturitas.2010.10.011

Rubber Hand Experiment Shows Kids Have More Flexible Body Boundaries

Close your eyes. Do you know where all your fingers and toes are? Can you pinpoint the exact edges of your body in space?

You may think your knowledge of your body is unshakeable, but a simple trick with a rubber limb can sway you. In kids, the effect is even more extreme—a finding that gives intriguing hints about how our body sense develops.

The new research relies on the "rubber hand illusion," first published in 1998. To produce this illusion, an experimenter sits across a table from a subject. The subject rests one hand, let's say the left, flat on the table and keeps the other hand in his lap. A little wall blocks the left hand from the subject's sight. But the subject can see a rubber hand, also a left hand, sitting on the table just inside the wall.

Actually, hold on, I'll draw you a picture.

OK. The experimenter (or, oval with glasses) holds two paintbrushes and uses them to stroke the backs of the real hand and the rubber one simultaneously. The subject watches these paintbrush strokes that seem to match the ones he's feeling, and eventually the brain takes a shortcut: it decides the seen hand and the felt hand are one and the same. This gives the subject the eerie impression that the rubber hand is part of his body. (I wrote about trying the rubber hand experiment for my eighth-grade science fair—and someone else's kooky version of the illusion that uses entire bodies instead of hands—here.)

University of London psychologist Dorothy Cowie and her colleagues tested the rubber hand illusion on kids of varying ages to see how their response compared to adults. Like researchers before them, they measured the effect in two ways. The first was a questionnaire about whether the rubber hand felt like the subject's own (for kids, the scale went from "definitely not" to "lots and lots").

For the second measurement, subjects closed their eyes and slid the index finger of their right hand under the edge of the table until they believed it was aligned with the index finger of their left hand. After experiencing this illusion, subjects tend to get skewed in the direction of the rubber hand.

The researchers tested adults as well as 90 kids between the ages of 4 and 9. They saw that in the sliding-finger measurement, kids in all age groups drifted farther toward the rubber hand than adults did. The results are reported in Psychological Science.

To explain this, Cowie suggests that people rely on two different methods to figure out where their body parts are. One combines vision and touch: do the cues I'm feeling match what I see? The illusion worked best for adults when the paintbrush strokes on both hands were perfectly in sync.

But for kids, the illusion stayed strong even when the paintbrush strokes they saw were out of sync with the ones they felt. This suggests that a second system of perception simply asks whether something that looks like our arm appears in roughly the place we expect it. Kids overuse this system, Cowie says. "Seeing a 'hand-like thing' in front of them on the table was enough to sway their perception of where their own hands were." By adulthood, Cowie thinks, we learn to pay more attention to tactical cues. "Adults rely less on the visual stuff than kids."

The fact that the illusion works at all demonstrates that "we don't just rely on muscle info to tell us where our body is," Cowie says, whether we're kids or adults. "In fact vision is really important!" Her research group is conducting further studies to find out how perception changes with age. "The results are absolutely always that kids are more susceptible than adults" to the illusion, she says.

If you're feeling worried that you don't know your body very well, consider taking on a more childlike attitude. Cowie says the kids in her experiment enjoyed being tricked by the illusion. One kid reacted with "You seem to have painted my hand!" They were eager to check where their hands really were when the test was over.

"Kids are actually open to weird stuff more than adults are," she says.


Cowie, D., Makin, T., & Bremner, A. (2013). Children's Responses to the Rubber-Hand Illusion Reveal Dissociable Pathways in Body Representation Psychological Science DOI: 10.1177/0956797612462902

Images: St0rmz (via Flickr); me (via Post-It note).

The Composer and the Cassowary: An Appreciation of Mistakes

High in a church balcony last weekend, waiting to perform a solo for Palm Sunday and trying not to panic, I thought about cars being hit with hammers. I'm not sure this is the kind of visualization recommended for singers. But sometimes genetics asserts itself.

A college biology professor once told my class that genetic mutation is like whacking a car with a hammer. You will almost never improve your car this way. More often, you'll damage it. If you're lucky the damage will be only superficial: a change in the silent portion of your genome, or maybe a few funny feathers.

The piece my choir was getting ready to sing, Gregorio Allegri's Miserere, has experienced some mutations in its own DNA over the centuries. Allegri composed the piece way back in the early 1600s, and after that it was sung exclusively during Holy Week at the Sistine Chapel. Even though people had to attend a 3 AM service in Rome to hear it, the Miserere became famous. The Vatican, wanting to keep the piece to itself, threatened excommunication for anyone who copied down the score.

As secrets and life forms tend to do, though, the music leaked out. In the late 18th century, a certain precocious teenager with the last name of Mozart spent Holy Week in Rome with his father. After hearing the Miserere at the Sistine Chapel, young Wolfgang sat down and transcribed the whole thing from memory. He returned for a second performance to double-check his work. From there, the score got into the hands of a music historian who published it.

If the music had really been genetic material, Mozart would have been DNA polymerase, a molecular machine that copies DNA. The polymerase molecule grasps a DNA strand and crawls along, letter by letter, building a matching strand as it goes.

Like Mozart, the enzyme is good at what it does. It proofreads. But sometimes it slips up: A single letter of DNA might be swapped for another one. A section of the code might be flipped backward. One or more letters might be inserted or deleted. (Even one letter lost or gained can cause a major change, since the DNA code is read in three-letter words. In English, imagine losing a letter from the sentence "SHE ATE THE RED BUG" and ending up with "SEA TET HER EDB UG." Some words are still there, but the meaning of the sentence is destroyed.)

Even if DNA polymerase is performing well, damage to the genome can come from outside sources such as UV radiation. But a large fraction of your DNA seems to do nothing at all. If a mutation happens here, you won't know the difference. If a slip-up creates a synonymous change in a gene—the code allows for some words to be spelled in multiple ways—you'll also be fine. And if the mutation does something horrible, it will remove you from the gene pool.

Evolution doesn't care much about any of this. It only notices the rare constructive strokes of the hammer, and it only sees them if they happen in the cells that will become your sperm and eggs (called the "germ line"). If you have DNA damage in the skin of your back from too much tanning, you can't pass it on to your children.

Back when Allegri's Miserere was being sung in the Sistine Chapel, the choirs were made up of men and boys. In choirs like mine, women sing the alto and soprano parts. But that's only a superficial mutation; we singers are the flesh of the piece.

The germ line mutation came in the 19th century. Someone who copied the piece apparently made a mistake, shifting a whole repeated section up by a fourth. What started out as a normal soprano solo now rocketed all the way to a high C, a preposterous note that humans are almost never asked to sing.*

Natural selection didn't weed out this mutation. Once the change had happened and been passed to new generations of the musical score, it stayed in place—even after the error was discovered. We continue to sing the mutated piece because, simply, it's awesome this way. Here's a video. You'll know when the boy soprano hits the high C: it's the note you hear through the bones of your spine instead of your ears.

It's not an overstatement to say that what happened to Allegri's music represents the whole history of life on Earth. Every new development has come from a mistake, small or egregious, that was allowed to stick around for one reason or another. Life started as tiny blobs, then whoops—heads! Legs! Oops again—tulips! Uncorrected errors became tree bark, snail shells, lungs, fur, resistance to antibiotics. Inching along mistake by mistake, life forms developed the machinery to make blood, slime, deadly venom, and spider silk.

Some living things have come together so elegantly that they bring an audience to its feet. There are racing cheetahs, swooping owls, orchids that mimic bees. But even the giant, gut-colored flower that stinks like a corpse to attract flies is a success in its family line. The cassowary is a bird that made so many mistakes, it traded the ability to fly for tree-trunk legs and a head with a sail on top. Even the cassowary, though, is doing something right. Errors become the high notes.

Postscript: My choir director turns out to have a son who, at age three, actually took a hammer to the family car while it was in the garage. The car was not improved. 

Images: Top, cassowary from The New Student's Reference Work and Gregorio Allegri, both via Wikimedia Commons. Bottom, cassowary by Peter Nijenhuis via Flickr.

*Plot clarification, in case anybody is worrying about me up there in the loft: this is not the part I sang.

The Shambulance: Deer Antlers Are Not Unicorn Horns

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. The chief navigational officer of the Shambulance today is Steven Swoap.

This Superbowl season saw a star linebacker forcefully denying that he'd ever sprayed juice made from ground-up deer antlers into his mouth. The player was Ray Lewis, and using deer antler spray would have seemingly violated the National Football League's ban on performance-enhancing drugs. Like the horn of a unicorn, this product is alleged to heal and strengthen its users. Also like the unicorn horn, it's probably not something the NFL needs to worry about.

Bottles of deer antler spray—also called deer antler velvet or IGF-1 spray—are legal and easy to purchase for $20 to $50. Though no one's checking what's actually inside the bottles, makers claim their products come from antlers that are harmlessly sawed off of male deer each spring, or from the soft skin covering these new antlers. A few times a day, you spritz the solution into your mouth and swallow it.

The suggestion is that deer antler spray will make your own muscles or bones regrow as rapidly as a deer's antlers. Some products make other claims that are variously expansive, including weight loss, better endurance, a boosted immune system, and higher sex drive. Fueling all these promises is a hormone called IGF-1 (short for insulin-like growth factor). Like medieval "unicorn horns" that were really the tusks of narwhals, IGF-1 is less glamorous in reality than in legend.

It's true that deer antlers "grow like crazy," says Steven Swoap, a physiologist at Williams College. "There are not many examples where a tissue grows faster than an antler. Except for maybe some pumpkins."

We humans are naturally curious about tapping into that growing power. And IGF-1 is certainly involved in growth. In humans as well as deer, it's mostly manufactured by the liver. We make more of it during growth spurts, Swoap says. Producing too much IGF-1 is linked to certain cancers—growth that can't be stopped.

"Does IGF-1 cause antler growth? It is possible," Swoap says. "A more likely candidate is testosterone." Female deer, which also make IGF-1, don't grow antlers; male deer have extra testosterone in their bodies during the antler-growing season. "There are likely many factors involved," Swoap says.

Whatever ingredient gives deer antlers their seemingly magical growing power, we aren't likely to capture much of it by grinding up the antlers themselves. "The antler is not a hormone producing factory," Swoap says. Antler growth is triggered by hormones sent from elsewhere in the body, such as the liver, thyroid, or testes. ("You would be much better off making a spray out of the testes of deer," Swoap suggests. "Or you could perhaps get the IGF-1 from the liver, where it is made, and have a liver milkshake with your deer nut spray.")

Even if a useful quantity of IGF-1 made it out of the antlers and into the spray, the molecule would have a hard time completing its journey into the hopeful athlete's body. Swoap says IGF-1 is a hefty protein that's unlikely to slip into your bloodstream through the soft tissues under your tongue. And once swallowed, it would break down in your digestive tract.

Swoap compares IGF-1 to another famous protein hormone: insulin. "For years, we had to inject it, and it is only recent technological advances that allowed us to deliver it subcutaneously," he says. "To say that the technology is replicated in a bottled spray is ridiculous."

Mitch Ross, the owner of the company that claimed Ray Lewis used its deer spray to recover from an injury, calls his products "technologies that are light years ahead of what people can understand." In other words, even if we can't explain the science, we should accept that deer antler extract helps people.

Except that it doesn't.

Researchers have given oral deer antler supplements to various groups of people, compared them with placebos, and looked for any effect. Men who took deer antler supplements during a strength training program showed no change in hormone levels (including IGF-1) and no difference in aerobic endurance. Rowers also showed no change in hormone levels and no difference in strength or endurance. (As for those other claims, a study in middle-aged men found no increase in sexual function.) A review paper last year concluded there is no convincing evidence that deer antler extract is useful to athletes.

It seems we haven't yet lopped anything special off the heads of those deer. Ray Lewis and (because even athletes who compete at a walk apparently want performance boosters) golfer Vijay Singh are busy defending their reputations against deer antler spray. Yet the product wouldn't have given them any extra powers except a placebo spritz of confidence. Professional sports organizations have plenty of real beasts to chase down in the world of banned substances, but this one is only a mythical creature.


Image: skipnclick (Flickr)

How to Cross the Deep Sea: Stepping Stones of Mollusk Poop

The seafloor has no shortage of spiky wildlife or hairy mysteries. One such mystery is logistical: where do the animals that live around deep-sea vents and cold seeps come from?

On the black and generally barren bottom of the ocean, food is scarce. Hydrothermal vents and cold seeps—places where methane, sulfides and other chemical goodies leak out of the seafloor—are like desert oases. Whole communities of weird creatures that live on these chemicals rather than the sun cluster around them.

Researchers think big pieces of organic junk that fall to the bottom of the ocean, such as sunken ships and deceased whales (called "whale falls"), may act as stepping stones for these communities. Species might disperse from one seafloor chimney to the next via a visit to a wrecked ship.

"Wood is a foreign substance in the deep sea," says Christina Bienhold of the Max Planck Institute. To find out whether resourceful ocean critters can easily make use of wood that falls into the ocean, she and other researchers dropped some in. They rigged together small heaps of Douglas fir logs, weighted them with cement, and carried them a mile down into the Mediterranean.

The researchers used four wood piles, each two meters long. They were at various distances from a known cold seep. The closest log was 70 meters away—so if any animals scooted over from that community, it would be a bit of a trek.

One of the wood heaps was sampled just one day later. (It looked the same.) The other three rested on the ocean floor for a year before robotic vehicles returned to collect wood samples and scoop up the animals that had moved in.

And did they ever move in. Bienhold was surprised to find that her logs, after only a year on the seafloor, held thriving colonies of wildlife.

The logs' most abundant tenants were wood-boring bivalves called Xylophaga, or "shipworms." Built like a worm with a shell on one end, these mollusks burrow into wood while symbiotic bacteria help them digest it. All around the logs were evidence of their work: the researchers observed a layer of "fine wood chips and fecal matter" two to four centimeters thick.

The shipworms seemed to have attracted other animals interested in feeding on the mollusks themselves or on the waste piles they left everywhere. As these creatures ate and respired, they used up oxygen in the water and allowed oxygen-hating bacteria to move in. These bacteria created pockets of sulfides—food for the kinds of animals that live at cold seeps or hydrothermal vents. (Normally, they would find this food coming straight out of the ground.)

Like very unattractive doves out of a hat, those animals began to materialize out of the blackness of the ocean. Clustered around the logs were sea urchins, fish, and deep-sea mussels and crabs. There were small crustaceans that couldn't be identified, and several types of worms, including two brand-new species.

All three wood piles had similar animal communities living on and around (and, in the case of the crabs, hiding underneath) them. Their bacterial communities were more diverse. But they all included bacteria that could break down the cellulose in wood, as well as bacteria that consume sulfate instead of oxygen.

Bienhold says her results show how wood that falls to the seafloor can create hotspots of ocean life. Hunks of organic trash like her log piles, even though they're few and far between on the bottom of the ocean, could help rare deep-sea species to spread. The key player in her set of experiments was the little wood-boring bivalve that moved in first and made the logs into a habitat that other wildlife could use.

"It remains enigmatic," Bienhold says, how the wood-borers (or any of the other organisms) found this new habitat in the first place. The researchers observed a greater density of sea urchins as they got closer to the wood piles; they seemed to be attracted to the wood by some chemical signal. Sea urchins and other animals may sniff out chemical cues from afar that help them find organic matter. For now, though, the secret remains sealed in their lipless bodies.

Bienhold C, Pop Ristova P, Wenzhöfer F, Dittmar T, & Boetius A (2013). How deep-sea wood falls sustain chemosynthetic life. PloS one, 8 (1) PMID: 23301092

Image: Sea urchins, courtesy of New Zealand-American Submarine Ring of Fire 2005 Exploration, NOAA Vents Program.

12 Days of Inkfish, Day 10: Acoustic Scavenger Hunt

On the beach of a tiny Scottish island, a person kicked and jumped through unusual "singing sands" that made a squeaky barking sound in response. More than 3,600 miles away, I was able to eavesdrop on the weird phenomenon because that person had uploaded a recording to the website Sound Around You.

This crowdsourced sound map is a project by researchers at the University of Salford in Manchester. Volunteers around the world have shared ambient noises or noteworthy moments from their environments. The researchers hope to learn about how our soundscapes make us feel, and how they affect our lives.

Exploring the map they've built so far, you can hear street music in Chile, a quiet countryside in Thailand, and chatter on an Italian bus. From Israel, someone has uploaded the wail of an air-raid siren. Once you start cupping your ear toward people and streets on the other side of the world, it's hard to turn away.

The ambient noises of wind and elevated trains in Chicago seem to be pretty well covered already. But if you live someplace with more interesting background noise, you can use a free app called i-SAY to capture (and share) the sounds around you.

Image: Sound Around You

12 Days of Inkfish, Day 5: Running on Water

Human courtship rituals—if you believe television commercials, anyway—are lame. The guy who kneels down right at the jewelry store counter ("It fits perfectly!" "Well honey, that's because I already had it sized") has nothing on birds who walk on water for each other.

Grebes are diving waterbirds that live in the Americas and Eurasia. To pair off, they follow an elaborate courtship choreography that includes trading bits of food and mimicking each other's motions. In the ritual's conclusion, both birds suddenly haul their ungainly bodies out of the water and run together on its surface. The grace of the birds and the physics of the maneuver both seem impossible.

You can see a pair of Clark's grebes do their courtship dance in this incredible video from the BBC. Jewelry companies, take note: there's no prelude to romance quite like swallowing a live fish.

Image: screen grab from BBC Life: Birds: Partners for Life

Cold and Hungry? Scientists Suggest Remembering Soup

Regrettably, and despite what the Breatharians will tell you, a person can't live on a diet of air. But you can keep hunger pangs at bay, scientists say, simply with the power of memory. And feelings of nostalgia can help you withstand cold, according to another group of scientists. Now that winter is settling in, it might be a good time for all of us to start collecting some really good soup experiences.

Researchers studied the effect of nostalgia on body temperature in a series of experiments reported in the journal Emotion. People may describe their fond thoughts of the past as "warm feelings," but do they really mean it?

In one experiment, 64 subjects individually sat in a room kept at a cool 16 degrees C (60 F). They were asked to recall either a memory that made them nostalgic or an "ordinary autobiographical event." After taking some time to reflect on the memory and record their feelings, subjects estimated the temperature of the room. The ordinary-memory people guessed about 17 C (63 F). But the nostalgic ones put the temperature higher, at around 20 C (a comfortable 68 F).

Another group of 80 volunteers reflected on a nostalgic or non-nostalgic memory, like the earlier group had. Afterward, they had to plunge one hand into a bowl of ice-cold water and hold it there for as long as they could. The non-nostalgic subjects lasted about 20 seconds before yanking their hands out of the bowl. Those fortified by warm, nostalgic memories, though, stuck it out for an average of 26 seconds.

A separate study, published this week in PLOS ONE, looked at how memory affects hunger. Patients with severe memory problems, the authors note, sometimes eat one full meal right after another—without recalling what they've eaten, they apparently don't feel full. For people with intact memories, does hunger also depend on our memory of our last meal?

To find out, researchers at the University of Bristol relied on a trick soup bowl. A hidden pump in the bowl's base, connected to a tube under the table, let scientists sneakily refill or drain the bowl while subjects were eating (surely this is the plot of a Greek myth I'm forgetting).

Researchers gave 100 subjects a bowl of "creamed tomato" soup that initially held either 500 ml (about 2 cups) or 300 ml (1 1/4 cups). Half the subjects were allowed to eat their soup with no funny business. A quarter of them saw a bowl holding the larger amount of soup but only ate the smaller amount as their bowls were secretly drained. And the final group saw a small bowl of soup but ate a larger portion as it refilled.

Over the next three hours, subjects rated how hungry they felt. By the end, people who had seen a small portion of soup felt significantly hungrier than those who had seen a large portion—regardless of the amount they'd actually eaten.

This suggests, the authors write, that appetite is closely tied to our memory of what we've eaten recently. We take visual hints from our food about how full it will make us feel, and those hints can override the information coming from our stomachs.

If you don't have a magic soup bowl, you might still be able to use your memory to your advantage by paying attention to what you eat. Previous research has shown that watching TV, or otherwise distracting ourselves during meals, can make us hungrier later on. Taking in all the visual information from our plates, so we remember it later, can keep us feeling fuller. And, of course, recalling fond memories might make us warmer. Maybe all that time Eliza Doolittle spent standing on the street and singing about "warm face, warm 'ands, warm feet!" would have been better spent looking to the past.


Zhou, X., Wildschut, T., Sedikides, C., Chen, X., & Vingerhoets, A. (2012). Heartwarming memories: Nostalgia maintains physiological comfort. Emotion, 12 (4), 678-684 DOI: 10.1037/a0027236

Brunstrom, J., Burn, J., Sell, N., Collingwood, J., Rogers, P., Wilkinson, L., Hinton, E., Maynard, O., & Ferriday, D. (2012). Episodic Memory and Appetite Regulation in Humans PLoS ONE, 7 (12) DOI: 10.1371/journal.pone.0050707

Image: Maria Pontikis (Flickr)

The Shambulance: Infrared Body Wraps

(The Shambulance is an occasional series in which I try to find out the truth about bogus or overhyped health products. Having recovered from my taste of no-calorie noodles, I'm back this week with Shambulance first officers Steven Swoap and Daniel Lynch.)

Sometimes it's for the best when product claims turn out to be blatant lies. If purveyors of infrared body wraps, for example, were telling the truth, clients would walk out of their spas dripping grease from their skin—and that wouldn't even be their biggest concern, next to the heart attacks.

All body wraps are not created equal. There are slimming volcanic ash wraps, herbal wraps, mud wraps, and even chocolate wraps. Some are only meant to be relaxing skin treatments. Others involve swaddling clients mummy-style in bandages and plastic wrap, then leaving them for an hour or so to stew in their own sweat.

These kinds of body wraps often promise weight loss or overall slimming. In reality, how much weight you lose will depend on how much water your body sweats out in a frantic effort to cool down. Additional svelte-ness might come from the squishing action of the tight bandages. Both effects will be temporary. 

As another benefit, spas that offer body wraps unfailingly promise "detox." This isn't the first time the d-word has come up here. Suffice it to say that unwanted molecules are filtered from our blood and sent out of our bodies by the liver and kidneys—not sucked from us forcefully by mud wraps, juice diets, or ionic foot baths.

But the most amazing promises of all come from the infrared body wrap. Unlike some of the body wrap's other incarnations, this treatment doesn't require you to strip down, be slathered in goo, and get bandaged head to toe. Instead, clients lie on a bed with their clothes on while several infrared-generating silicone pads are strapped around them. Then they're left under a heated blanket for a while.

So far, it sounds like nothing more than a toasty nap. But spas say that you'll leave an infrared wrap session skinnier and healthier, with better circulation, a faster metabolism, clearer skin, and less cellulite. How?

The pads give off long and short infrared waves that penetrate deep into your fat layers, websites claim, increasing your body temperature, metabolism, and blood circulation. The heat "break[s] down fats into a liquid form, allowing secretion of body water, toxins and fat as you perspire," according to one Chicago spa.

All that formerly stored fat, once liquefied by the infrared waves, is obviously eager to escape your body through the nearest exit. But don't worry if the fat gets stuck inside you—you'll burn it anyway. "You can burn 900 to 1,400 calories or more in just one 50 minute session," another Chicago site proclaims.

After studying this calorie chart, I'm thinking I've been wasting my time by walking to work. What I should really do is buy some of these silicone pads, strap them on, and see if I can get someone to roll me there.

This is "completely insane," says Williams College physiologist Steven Swoap. "How are they allowed to write this stuff?"

For one thing, "Fats simply don't come out of sweat glands," he says. Though if they did, you would definitely have to throw away your spa outfit after soaking it with grease from the inside.

Infrared radiation, Swoap explains, isn't a magical cellulite-blasting weapon. In fact, people naturally give off long infrared waves as body heat. "Instead of wrapping yourself with this stuff, maybe a good long hug with your significant other would work too," Swoap says. Or, if you're looking for shorter infrared waves, "You could take your TV zapper and shoot it at yourself all day long."

Daniel Lynch, a Williams College biochemist, says that heating parts of your body could certainly increase your water loss. But your fat isn't budging. "To get rid of the fat, it must be metabolized," he says, "and that is not going to be enhanced by lying on a bed with silicone wraps on your legs."

Furthermore, Lynch speculates, if your fat deposits really did get broken down and sent back into your blood—and you were, say, lying on a table instead of using those fat molecules for fuel—"You could actually have dangerous levels of fatty acids circulating in your blood. That's good for a heart attack!"

If you're looking for an exercise-free way to burn fat, Swoap suggests hanging out in a cold room rather than under a warm blanket. Being in the cold will raise your metabolism as your body tries to replace the heat you're losing. If you're still hankering after the spa experience, you could always wait until winter, wrap up in a scarf, and have someone log-roll you down the sidewalk.

Images: Top, Leah Chavie Skincare Boutique; middle, Formostar Infrared Body Wrap System; calorie chart, Formostar Infrared Body Wrap System.

Subliminal Placebo: You Didn't See It, but It's Working

The latest additions to the placebo effect family might be the rudest. First there was placebo, which uses your body's own tools to make you feel better after you try a treatment you imagine will help you. Then there was nocebo, placebo's evil twin: it makes you feel worse only because you think you will. Now researchers have discovered that placebo and nocebo effects can be triggered subliminally, which is like finding out that the good and evil twins have both been living in your basement without you knowing it.

Usually, placebo and nocebo look like cases of our own expectations manipulating us. Someone swallows his favorite headache remedy or visits a doctor, and his body, expecting to feel better, ramps up production of its own pain-relief molecules. Someone else steps onboard a plane and begins to feel nauseous, simply because her body has learned that airplanes mean queasiness. If we were more ignorant of our circumstances, the effects wouldn't be there.

But there seem to be some cues we can take in subliminally, without noticing them. So researchers led by Karin Jensen at Harvard Medical School wondered whether visual signals that are too brief to reach our consciousness—but perhaps not too brief for certain areas of our brains to snag as they pass—can trigger placebo and nocebo effects too.

For their visual signals, the team chose photos of male faces. "We know from previous studies that faces can be detected and processed very quickly in the brain," Jensen says. Their models came from a set of photos created for use in psychology experiments.

The researchers carried out two experiments, the first of which was a classic test of placebo and nocebo. Subjects were shown pictures of two expressionless male faces over and over. Each time they saw face A, they felt a painfully hot sensation on the forearm. Face B was paired with heat that was milder, but still uncomfortable. (The A and B models alternated between different subjects—just in case one man's face really was more painful to look at.) During the conditioning part of the experiment, subjects saw each face 25 times. This taught them to expect higher pain with face A and lower pain with face B.

Then came a second series where subjects saw the same two faces as before, with a few new ones mixed in as controls. With each face they saw, subjects rated the pain they felt from the heat instrument on a 100-point scale. The twist was that in this part of the experiment, the heat level was exactly the same every time. But subjects consistently reported high pain for face A and low pain for face B. When they saw a new face, subjects reported an intermediate level of pain (which corresponded to what they were actually feeling).

This first experiment showed the researchers that pairing faces with painful heat stimuli could create both a placebo effect (when subjects rated moderate heat as less painful because they saw face B) and a nocebo effect (when subjects found moderate heat more painful, thanks to face A). So they moved on to the second experiment. In this round, the visual signals would be "nonconscious,"or subliminal.

A new group of subjects went through the same conditioning sequence as before. Then they were given a testing sequence using face A, face B, and the new (control) faces, all paired with the same moderate heat on the arm. But the faces in this sequence flashed on the screen for just 12 milliseconds, compared to 100 milliseconds in the earlier experiment.

12 milliseconds is fast. Too fast, in fact, for subjects to consciously process the faces zipping by. They reported that they couldn't tell who was who (and a separate experiment confirmed that people can't recognize faces shown this quickly).

But, as the researchers report this week in PNAS, the pain scores still matched the faces subjects said they couldn't see. Face A got significantly higher pain scores than face B, with the control faces scoring in the middle—and don't forget that, once again, subjects were actually feeling the same degree of heat every time.

Even though the pictures flashed too briefly to enter conscious awareness, they seem to have snuck in through the brain's back door. These visual cues made subjects experience more or less pain than they should have, even though they had no idea what they'd seen.

There were only 20 subjects in each experiment; it would take further studies to show how consistent or how powerful the subliminal placebo and nocebo effects are. But the fact that they found an effect at all is exciting news to the researchers. "To the best of my knowledge, there has not been an experiment [previously] where placebo/nocebo effects have been activated by nonconscious cues," Jensen says.

The common assumption, Jensen says, is that placebo and nocebo rely on the signals we're paying attention to (pills, needles, drug commercials) and the results we expect (relief, discomfort, alarming side effects). But this study "proves that we don't need to be aware of the cue to elicit a conditioned response," Jensen says.

Don't expect to start seeing mysterious images flashing at you in the doctor's office. The subjects in Jensen's study had to be trained to associate photos of faces with high or low pain. And even if there were another kind of image that automatically produced a placebo effect in a wide audience (teddy bears? puppies?), our brains might not be able to recognize it as quickly as a human face.

But the idea that placebo and nocebo effects can be triggered by cues patients don't even notice could be important for healthcare, Jensen says. Certain conditions such as asthma, depression, and irritable bowel syndrome are known to respond well to placebos. Maybe doctors' offices and hospitals in the future will tailor everything patients see—from the posters on the wall to the instruments on the counter to the fish swimming in the lobby aquarium—to encourage placebo and avoid nocebo. Or maybe we'll be able to use the same tricks at home to keep ourselves feeling our best. Let's kick those weird placebo relatives out of the basement and put them to work.

Karin B. Jensen, Ted J. Kaptchuk, Irving Kirsch, Jacqueline Raicek, Kara M. Lindstrom, Chantal Berna, Randy L. Gollub, Martin Ingvar, & and Jian Kong (2012). Nonconscious activation of placebo and nocebo pain responses PNAS : 10.1073/pnas.1202056109

Image: freya.gefn/Flickr