by Alex Boese
Subsequent research, such as investigations of lesbian couples and mothers and daughters living together, has largely confirmed McClintock’s findings, but her study left unanswered an important question. What causes menstrual synchrony?
McClintock speculated that, just as in rats, the culprit was airborne pheromones—or, put more plainly, the scent of other women. But it wasn’t until 1998, when she was a professor at the University of Chicago, that she was able to prove it. She instructed nine women to wear sweat-collecting pads in their armpits for eight hours. She then wiped these sweaty pads beneath the noses of twenty other women (who didn’t know what it was they were being wiped with). McClintock found that the cycles of the second group altered depending on whether they were wiped with the sweat of a woman late or early in her cycle. She concluded that a chemical messenger in the sweat (i.e., pheromones) was influencing the timing of the other women’s menstrual cycles.
This experiment, in turn, raised another question. If pheromones can affect human biology, how do they have this effect? A few scientists have suggested that humans possess a previously unknown sixth sense that detects pheromones. After years of peering up people’s nostrils, researchers such as Luis Monti-Bloch and David Berliner declared the discovery of a sixth sense organ—the vomeronasal organ. If they’re right, this tiny pit, located about half an inch inside the nose, detects pheromones. It’s well known to exist in other animals, but humans were thought to be lacking it. It’s so small that most anatomists simply overlooked it.
These discoveries have inspired numerous entrepreneurs to jump on the pheromone bandwagon, advertising pheromone-laced sprays that will, they claim, make their wearer irresistible to the opposite sex. It’s doubtful these work. But it’s not out of the realm of possibility that one day we might see genuine pheromone-based products on grocery-store shelves. We might even be able to buy “McClintock, the menstrual-cycle altering perfume.”
McClintock, M. K. (1971). “Menstrual Synchrony and Suppression.” Nature 229: 244–45.
The Smell of Money
You’ve got a drink in your hand. You’re popping quarters into the slot-machine. The sound of falling coins rings in your ears. Money being won! Your adrenaline is pumping. And boy, something smells good!
In 1991 Dr. Alan Hirsch introduced two different odors, both rated as pleasant in prior preference studies, into different areas of the gaming floor of the Las Vegas Hilton. The odors were strong enough to be easily perceived, but were not overpowering. A third area he left odor-free. Odorization occurred over a period of forty-eight hours.
The results were startling. One of the odorized areas saw a 45 percent jump in the amount of money spent at the machines compared to the week before. The second odorized area and the odor-free zone saw no increases. The first odor appeared to have caused people to spend more money—a lot more money.
There were no pheromones in these odors. They were simply pleasant aromas. Also, Dr. Hirsch had no idea why the first odor, but not the second, caused the dramatic spike in gaming revenue. He had expected both to have some effect. Nevertheless, the gaming industry and retailers throughout the country immediately took notice. Easy money, they thought, never smelled so good. Pump in a few good scents and wait for the cash to roll in.
Rival researchers, however, criticized Hirsch’s work, complaining that he never identified the jackpot scent, making it impossible for them to evaluate his results. Consumer groups, on the other hand, decried the dawning of an era of manipulative smell technology.
Since the early 1990s researchers have continued to investigate the smell-sells phenomenon, but results have been ambiguous at best. Some studies show positive effects, whereas others show none. Marketing professors Paula Fitzgerald Bone and Pam Scholder Ellen, reviewing this research in a 1999 article, cautioned that “evidence is stacked against the proposition that the simple presence of an odor affects a retail customer’s behavior.” Such words of warning hardly dented the enthusiasm of retailers, who, if anything, have become even more excited about odor in recent years. Some businesses have gone so far as to develop signature scents. Samsung, for instance, fills its stores with a distinctive honeydew melon smell, and Westin hotels pump a white tea fragrance into their lobbies. So the next time you’re in a store and you stop to smell the roses—or the melon, vanilla, cucumber, lavender, or citrus—remember that the business owner is hoping soon to be counting your cash.
Hirsch, A. R. (1995). “Effects of Ambient Odors on Slot-Machine Usage in a Las Vegas Casino.” Psychology and Marketing 12 (7): 585–94.
Smell Illusions
Lift this book to your nose. Its pages have been coated with an odor-producing chemical. Can you smell it? If not, scratch a page to release the scent more fully. The aroma is pleasant and fruity. Can you smell it now? Yes? No?
Well, maybe not. The book contains no scratch-n-sniff odor. At least, it shouldn’t. Nevertheless, some readers may, through mere suggestion, have smelled something. Or believed they did.
Suggestion exerts a powerful influence over what we smell. Edwin Slosson, professor of chemistry at the University of Wyoming, demonstrated this in 1899 when he stood before his students and poured a vial of distilled water over a ball of cotton wool. The water, he told them, was a highly aromatic chemical. He asked them to raise their hands when they could smell it. Within fifteen seconds most of the front row had their hands in the air. Forty-five seconds later, three-quarters of the audience were waving at him.
Slosson provided few details about his experiment, and so it barely rises above the level of anecdote. But on the evening of June 12, 1977, viewers of Reports Extra, a late-night British news show, became the unwitting subjects in a better-documented demonstration of the same phenomenon.
The show, which aired in Manchester, focused on the chemistry of sense. Toward the end of the program, viewers were shown a large cone with wires protruding from its point. The cone, they were told, represented a new form of technology—Raman spectroscopy. It would allow the station to transmit smells over the airwaves, from the studio straight into a viewer’s living room.
The cone contained a “commonly known odorous substance” that exuded a “pleasant country smell, not manure.” The scent had been building up in the cone for the past twenty-three hours. Sensors were recording the vibrational frequencies of the odor molecules. These frequencies could then be broadcast over the air. Viewers’ brains would interpret the frequencies as smells. Voilà! Smell-o-vision made real.
The station announced that an experimental smell transmission would occur in a few seconds. They asked viewers to report whatever they smelled, even if they smelled nothing at all. Then three, two, one . . . The screen changed to an oscilloscope pattern and a tuning noise was heard. The smell had been transmitted.
Within the next twenty-four hours, the station received 179 responses. The highest number came from people who reported smelling hay or grass. Others reported their living rooms filling with the scent of flowers, lavender, apple blossom, fruits, potatoes, and even homemade bread. A few smelled manure, despite this odor having been specifically excluded. Two people complained that the transmission brought on a severe bout of hay fever. Three others claimed the tone cleared their sinuses. Only sixteen people reported no smell sensation.
What is one to make of this? As far as the TV station knew, they had not actually beamed a smell over the airwaves, unless they accidentally did so by some unknown mechanism. The transmission was an experiment devised by Michael O’Mahony, a psychology lecturer at Bristol University (now at the University of California, Davis). He conceded that some respondents may have been lying, but assuming the majority told the truth, he offered what happened as a successful demonstration of the power of suggestion. He speculated that the suggestion worked either by causing people to imagine a nonexistent smell, or by prompting them to focus on a previously unnoticed odor in their environment.
Recent research indicates that suggestion not only influ
ences what we smell, but also how we react to smells. In 2005 researchers at Oxford University asked subjects to sniff two odors, one labeled cheddar cheese and the other body odor. Predictably, the subjects rated the body odor as significantly more unpleasant. However, the two smells were identical. Only the labels differed. Consider that the next time you’re enjoying some especially pungent cheese at a cocktail party.
O’Mahony, M. (1978). “Smell illusions and suggestions: Reports of smells contingent on tones played on television and radio.” Chemical Senses and Flavour 3 (2): 183–89.
4. SIGHT
The Invisible Gorilla
You think it’s going to be a test of your powers of concentration, and in a way it is. The researcher tells you he’s going to show you a video of two teams, one dressed in black and the other in white, each throwing a basketball around. He asks you to count the number of times the white team passes the ball.
The video begins. The team members bob and weave. It’s a little difficult to follow them. There are so many bodies moving around. But you think you’re doing a pretty good job. You count the passes: one, two, three, four . . .
After about a minute the researcher stops the tape. You’ve got your number ready. “Fifteen passes,” you tell him, but then he asks you something unexpected: “Did you notice the gorilla?”
Huh? You shake your head. What gorilla? “The gorilla that walked to the center of the screen, thumped its chest a few times, and then walked offscreen,” the researcher replies. You look at him as though he’s crazy. There was no gorilla in that video. But then he replays the tape and, sure enough, about halfway through it, a person in a gorilla suit does wander into the crowd of basketball players and thump her chest. How in the world did you miss that?
If you ever take the test described above, don’t be surprised if you miss the gorilla. On average, 50 percent of first-time test takers fail to see it. Though, of course, now that you know the trick, you’ll be looking for it. People who are simply asked to watch the video, with no further instructions, almost always see the creature.
Researchers Daniel Simons and Christopher Chabris conducted the gorilla experiment in 1998. They explain that so many people miss the hairy primate because of a visual phenomenon known as inattentional blindness. Our brains are only capable of focusing on a few details at any one time. We tune out everything else, literally becoming blind to it, even if we’re staring right at it. So if something unexpected pops up—such as a woman in a gorilla suit—we fail to see it.
This explains why you might fail to notice friends waving at you in a crowded theater, because you’re focusing on looking for an empty seat. Or why a pilot who’s concentrating on an instrument display projected onto the windshield might not spot an unlooked-for plane crossing the runway up ahead. Perhaps it also explains why Bigfoot has eluded detection for so long. These unexpected “gorillas in our midst,” as Simons and Chabris put it, are simply hard to see.
Incidentally, people who were asked to focus on the black-clothed team saw the gorilla far more often—83 percent of the time. Presumably this is because subjects who were visually tracking white-clothed players tuned out anything black, including black gorillas. If, instead, Ricardo Montalban had wandered by in a white suit, those who followed the black team probably would have missed him.
Perhaps the optical illusion Simons and Chabris revealed is merely an artifact of a lab setting. Surely in real life we would notice the gorilla. However, in the mid-1990s Simons and a different colleague, Daniel Levin, conducted an experiment that suggests not.
One of the researchers posed as a tourist seeking directions and approached random pedestrians on the campus of Cornell University. “Excuse me, do you know where Olin Library is?” he asked as he fumbled with a map. The researcher and the pedestrian conversed briefly, until workmen carrying a door suddenly barged between them. A moment later they resumed their conversation.
However, something had changed when the door passed between them. One of the workmen carrying the door was actually the second researcher, who surreptitiously switched places with his colleague and continued to converse with the pedestrian as though he had been there the entire time.
The two researchers were approximately the same age, but were dressed in different clothes. Amazingly, over half the subjects, eight out of fifteen, didn’t realize they were talking to a new person until the researcher stopped them and asked, “Did you notice anything unusual at all when that door passed by a minute ago?” Many people replied, “Yes, those workmen were very rude.” To which the researcher would reply, “Did you notice that I’m not the same person who approached you to ask for directions?” A bewildered look followed.
Like the invisible-gorilla test, the changing-tourist experiment reveals that we often fail to notice unexpected changes to an attended object. This phenomenon is known as “change blindness.” Becoming aware of it can be rather unnerving. How much of the world around us might we be missing, one has to wonder. And can we ever again trust people who stop us and ask for directions on university campuses?
Of course, experiencing these effects for yourself is far more powerful than reading about them. If you go to Professor Simons’s Web site, http://viscog.beckman.uiuc.edu/media/Boese.html, you can view videos of his research, including the experiments discussed above. However, you’ll want to keep a close eye on the site. It has the potential to change at any time.
Simons, D. J., & C. F. Chabris (1999). “Gorillas in our midst: Sustained inattentional blindness for dynamic events.” Perception 28: 1059–74.
Through a Cat’s Eyes
A young man stares at a movie screen. Restraints hold him in his chair. Small clamps keep his eyes pried open. He cannot blink. He must continue to watch as scene after scene of graphic violence plays on the screen.
Fans of Stanley Kubrick will recognize this scene from his movie A Clockwork Orange. The main character, Alex DeLarge, is subjected to a treatment called Ludovico aversion therapy, designed to transform him from an unruly thug into a nonviolent, productive member of society. The treatment causes him to be crippled by nausea if he so much as thinks about violence, but it leads to tragic consequences. When released, Alex discovers he is powerless to defend himself against his numerous enemies, who duly take revenge on him.
Twenty-one years after the release of Kubrick’s film, a strangely similar scene played out in a University of California laboratory—with one major difference. In Alex’s place was an adult cat.
Researchers led by Dr. Yang Dan, an assistant professor of neurobiology, anesthetized a cat with Sodium Pentothal, chemically paralyzed it with Norcuron, and secured it tightly in a surgical frame. They then glued metal posts to the whites of its eyes, forcing it to look at a screen. Scene after scene played on the screen, but instead of images of graphic violence, the cat had to watch something almost as terrifying—swaying trees and turtleneck-wearing men.
This was not a form of Clockwork Orange–style aversion therapy for cats. Instead, it was a remarkable attempt to tap into another creature’s brain and see directly through its eyes. The researchers had inserted fiber electrodes into the vision-processing center of the cat’s brain, a small group of cells called the lateral geniculate nucleus. The electrodes measured the electrical activity of the cells and transmitted this information to a nearby computer. Software then decoded the information and transformed it into a visual image.
The cat watched eight different short movies, and from the cat’s brain the researchers extracted images that were very blurry, but were recognizably scenes from the movies. There were the trees, and there was that guy in the turtleneck. The researchers suggested that the picture quality could be improved in future experiments by measuring the activity of a larger number of brain cells.
The researchers had a purely scientific motive for the experiment. They hoped to gain insight into “the functions of neuronal circuits in sensory processing.” But the commercial potential of the technology is mi
nd-boggling. Imagine being able to see exactly what your cat is up to on its midnight prowls. Forget helmet cam at the Super Bowl; get ready for eye cam. Or how about this—never carry a camera again. Take pictures by blinking your eyes. Then annoy your online friends with endless cat photos streamed straight from your brain.
Dan, Y., et al. (1999). “Reconstruction of Natural Scenes from Ensemble Responses in the Lateral Geniculate Nucleus.” Journal of Neuroscience 19 (18): 8036–42.
5. SOUND
The Mozart Effect
Mozart has a new hangout. No longer relegated to the dusty stereos of classical-music buffs, he can now be heard drowning out the sounds of crying babies and squealing Teletubbies at the local nursery, or blasting from high-end toys and crib mobiles.
Why has Mozart become so popular with the under-five set? The reason traces back to the startling results of a 1993 experiment performed by Frances Rauscher, Gordon Shaw, and Katherine Ky at the University of California, Irvine.
In the experiment, thirty-six college students each tried to solve three sets of spatial-reasoning tasks. A typical task consisted of imagining a piece of paper folded and cut in various ways, and then figuring out what the paper would look like unfolded. Before starting each new task, the subjects sat through a different ten-minute “listening condition.” Before the first task they heard Mozart’s Sonata for Two Pianos in D Major, K. 448; before the second one, a blood-pressure-lowering relaxation tape; and prior to the third, silence.
The final results showed a clear trend. The students scored highest on the task after listening to Mozart. In fact, the improvement was quite dramatic: “The IQs of subjects participating in the music condition were 8–9 points above their IQ scores in the other two conditions.”