Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School (22 page)

Smell signals appear to be in a real hurry to take these shortcuts, so much so that olfactory receptor cells aren’t even guarded by a protective barrier. This is different from most other sensory receptor cells in the human body. Visual receptor neurons in the retina are protected by the cornea, for example. Receptor neurons that allow hearing in our ears are protected by the eardrum. The only things protecting receptor neurons for smell are boogers. Otherwise, they are directly exposed to the air.

ideas

There is no question that multiple cues, dished up via different senses, enhance learning. They speed up responses, increase accuracy, improve stimulation detection, and enrich encoding at the moment of learning. Yet we still aren’t harnessing these benefits on a regular basis in our classrooms and boardrooms. Here are a couple of ideas that come to mind.

Multisensory school lessons

As we learned in the Attention chapter, the opening moments of a lecture are cognitive hallowed ground. It is the one time teachers automatically have more student minds paying attention to them. If presentations during that critical time were multisensory, overall retention might increase. We discovered in the Memory chapters that repeating information in timed intervals helps stabilize memory. What if we introduced information as a multisensory experience, and then repeated not only the information but also one of the modes of presentation? The first re-exposure might be presented visually, for example; the next, auditorially; the third, kinesthetically. Would that encoding-rich schedule increase retention in real-world environments, boosting the already robust influence of repetition?

And let’s not continue to neglect our other senses. We saw that touch and smell are capable of making powerful contributions to the learning process. What if we began to think seriously about how to adopt them into the classroom, perhaps in combination with more traditional learning presentations? Would we capture their boosting effects, too?

One study showed that a combination of smell and sleep improved declarative-memory consolidation. The delightful experiment used a card game my sons and I play on a regular basis. The game involves a specialized 52-card deck we purchased at a museum, resplendent with 26 pairs of animals. We turn all of the cards face down, then start selecting two cards to find matches. It is a test of declarative memory. The one with the most correct pairs wins the game.

In the experiment, the control groups played the game normally. But the experimental groups didn’t. They played the game in the presence of rose scent. Then everybody went to bed. The control groups were allowed to sleep unperturbed. Soon after the snoring began in the experimental groups, however, the researchers filled their rooms with the same rose scent. Upon awakening, the subjects were tested on their knowledge of where the matches had been discovered on the previous day. Those subjects without the scent answered correctly 86 percent of the time. Those re-exposed to the scent answered correctly 97 percent of the time. Brain imaging experiments showed the direct involvement of the hippocampus. It is quite possible that the smell enhanced recall during the offline processing that normally occurs during sleep.

In the highly competitive world of school performance, there are parents who would die to give their kids an 11 percent edge over the competition. Some CEOs would appreciate such an advantage, too, in the face of anxious shareholders.

Sensory branding

Author Judith Viorst once said, “Strength is the capacity to break a chocolate bar into four pieces, and then eat just one of the pieces.” She was of course referring to the power of the confection on self-will. It’s a testament to the power of emotion to incite action. That’s just what emotions do: affect motivations. As we discussed in the Attention chapter, emotions are used by the brain to select certain inputs for closer inspection. Because smells stimulate areas in the brain responsible for creating emotions as well as memories, a number of business people have asked, “Can smell, which can affect motivation, also affect sales?”

One company tested the effects of smell on business and found a whopper of a result. Emitting the scent of chocolate from a vending machine, it found, drove chocolate sales up 60 percent. That’s quite a motivation. The same company installed a waffle-cone-smell emitter near a location-challenged ice cream shop (it was inside a large hotel and hard to find). Sales soared 50 percent, leading the inventor to coin the term “aroma billboard” to describe the technique.

Welcome to the world of sensory branding. An entire industry is beginning to pay attention to human sensory responses, with smell as the centerpiece. In an experiment for a clothing store, investigators subtly wafted the smell of vanilla in the women’s department, a scent known to produce a positive response among women. In the men’s department, they diffused the smell of rose maroc, a spicy, honeylike fragrance that had been pretested on men. The retail results were amazing. When the scents were deployed, sales doubled from their typical average in each department. And when the scents were reversed—vanilla for men and rose maroc for women—sales plummeted below their typical average. The conclusion? Smell works, but only when deployed in a particular way. “You can’t just use a pleasant scent and expect it to work,” says Eric Spangenberg, the scientist in charge of the work. “It has to be congruent.”

In recognition of this fact, Starbucks does not allow employees to wear perfume on company time. It interferes with the seductive smell of the coffee they serve and its potential to attract customers.

Marketing professionals have begun to come up with recommendations for the use of smell in differentiating a brand: First, match the scent with the hopes and needs of the target market. The pleasant smell of coffee may remind a busy executive of the comforts of home, a welcome relief when about to close a deal.

Second, integrate the odor with the “personality” of the object for sale. The fresh smell of a forest, or the salty odor of a beach, might evoke a sense of adventure more so than, say, the smell of vanilla, in potential buyers of SUVs. Remember the Proust effect, that smell can evoke memory.

Smells at work (not coming from the fridge)

What about the role of learning in a business setting? Two ideas come to mind, based loosely on my teaching experiences. I occasionally teach a molecular biology class for engineers, and one time I decided to do my own little Proust experiment. (There was nothing rigorous about this little parlor investigation; it was simply an informal inquiry.) Every time I taught one section on an enzyme (called RNA polymerase II), I prepped the room by squirting the perfume Brut on one wall. In an identical class in another building, I taught the same material, but I did not squirt Brut when describing the enzyme. Then I tested everybody, squirting the perfume into both classrooms. Every time I did this experiment, I got the same result. The people who were exposed to the perfume during learning did better on subject matter pertaining to the enzyme— sometimes dramatically better—than those who were not.

And that led me to an idea. Many businesses have a need to teach their clients about their products, from how to implement software to how to repair airplane engines. For financial reasons, the classes are often compressed for time and packed with information, 90 percent of which is forgotten a
day
later. (For most declarative subjects, memory degradation starts the first few hours after the teaching is finished.) But what if the teacher paired a smell with each lesson, as in my Brut experiment? One might even expose the students to the smell while they are asleep. The students could not help but associate the autobiographical experience of the class—complete with the intense transfer of information—with the odorant.

After the class, the students (let’s say they’re learning to repair airplane engines) return to their company. Two weeks later, they are confronted with a room full of newly broken engines to repair. Most of them will have forgotten something in the intense class they took and need to review their notes. This review would take place in the presence of the smell they encountered during the learning. Would it give a boost to their memories? What if they were exposed to the smell while they were in the shop repairing the actual engines? The enhanced memory might improve performance, even cut down on errors.

Sound preposterous? Possibly. Indeed, one must be careful to tease out context-dependent learning (remember those dive suits from Chapter 5) from true multisensory environments. But it’s a start toward thinking about learning environments that go beyond the normal near-addiction to visual and auditory information. It is an area where much potential research fruit lies—truly a place for brain scientists, educators and business professionals to work together in a practical way.

Summary

Rule #9
Stimulate more of the senses at the same time.

• We absorb information about an event through our senses, translate it into electrical signals (some for sight, others from sound, etc.), disperse those signals to separate parts of the brain, then reconstruct what happened, eventually perceiving the event as a whole.

• The brain seems to rely partly on past experience in deciding how to combine these signals, so two people can perceive the same event very differently.

• Our senses evolved to work together—vision influencing hearing, for example—which means that we learn best if we stimulate several senses at once.

• Smells have an unusual power to bring back memories, maybe because smell signals bypass the thalamus and head straight to their destinations, which include that supervisor of emotions known as the amygdala.

Get more at www.brainrules.net/sensory-integration

The evidence lies with a group of 54 wine aficionados. Stay with me here. To the untrained ear, the vocabularies that wine tasters use to describe wine may seem pretentious, more reminiscent of a psychologist describing a patient. (“Aggressive complexity, with just a subtle hint of shyness” is something I once heard at a wine-tasting soirée to which I was mistakenly invited—and from which, once picked off the floor rolling with laughter, I was hurriedly escorted out the door).

These words are taken very seriously by the professionals, however. A specific vocabulary exists for white wines and a specific vocabulary for red wines, and the two are never supposed to cross. Given how individually we each perceive any sense, I have often wondered how objective these tasters actually could be. So, apparently, did a group of brain researchers in Europe. They descended upon ground zero of the wine-tasting world, the University of Bordeaux, and asked: “What if we dropped odorless, tasteless red dye into white wines, then gave it to 54 wine-tasting professionals?” With only visual sense altered, how would the enologists now describe their wine? Would their delicate palates see through the ruse, or would their noses be fooled? The answer is “their noses would be fooled.” When the wine tasters encountered the altered whites, every one of them employed the vocabulary of the reds. The visual inputs seemed to trump their other highly trained senses.

Folks in the scientific community had a field day. Professional research papers were published with titles like “The Color of Odors” and “The Nose Smells What the Eye Sees.” That’s about as much frat boy behavior as prestigious brain journals tolerate, and you can almost see the wicked gleam in the researchers’ eyes. Data such as these point to the nuts and bolts of this chapter’s Brain Rule. Visual processing doesn’t just assist in the perception of our world. It dominates the perception of our world. Starting with basic biology, let’s find out why.

a hollywood horde

We see with our brains.

This central finding, after years of study, is deceptively simple. It is made more misleading because the internal mechanics of vision seem easy to understand. First, light (groups of photons, actually) enters our eyes, where it is bent by the cornea, the fluid-filled structure upon which your contacts normally sit. Then the light travels through the eye to the lens, where it is focused and allowed to strike the retina, a group of neurons in the back of the eye. The collision generates electric signals in these cells, and the signals travel deep into the brain via the optic nerve. The brain then interprets the electrical information, and we become visually aware. These steps seem effortless, 100 percent trustworthy, capable of providing a completely accurate representation of what’s actually out there.

Though we are used to thinking about our vision in such reliable terms, nothing in that last sentence is true. The process is extremely complex, seldom provides a completely accurate representation of our world, and is not 100 percent trustworthy. Many people think that the brain’s visual system works like a camera, simply collecting and processing the raw visual data provided by our outside world. Such analogies mostly describe the function of the eye, however, and not particularly well. We actually experience our visual environment as a fully analyzed
opinion
about what the brain thinks is out there.

We thought that the brain processed information such as color, texture, motion, depth, and form in discrete areas; higher-level structures in the brain then gave meaning to these features, and we suddenly obtained a visual perception. This is very similar to the steps discussed in the Multisensory chapter: sensing, routing, and perception, using bottom-up and top-down methods. It is becoming clearer that we need to amend this notion. We now know that visual analysis starts surprisingly early on, beginning when light strikes the retina. In the old days, we thought this collision was a mechanical, automated process: A photon shocked a retinal nerve cell into cracking off some electrical signal, which eventually found its way to the back of our heads. All perceptual heavy lifting was done afterward, deep in the bowels of the brain. There is strong evidence that this is not only a simplistic explanation of what goes on. It is a wrong explanation.

Rather than acting like a passive antenna, the retina appears to quickly process the electrical patterns before it sends anything off to Mission Control. Specialized nerve cells deep within the retina interpret the patterns of photons striking the retina, assemble the patterns into partial “movies,” and then send these movies off to the back of our heads. The retina, it seems, is filled with teams of tiny Martin Scorseses. These movies are called tracks. Tracks are coherent, though partial, abstractions of specific features of the visual environment. One track appears to transmit a movie you might call
Eye Meets Wireframe
. It is composed only of outlines, or edges. Another makes a film you might call
Eye Meets Motion
, processing only the movement of an object (and often in a specific direction). Another makes
Eye Meets Shadows
. There may be as many as 12 of these tracks operating simultaneously in the retina, sending off interpretations of specific features of the visual field. This new view is quite unexpected. It’s like discovering that the reason your TV gives you feature films is that your cable is infested by a dozen amateur independent filmmakers, hard at work creating the feature while you watch it.

streams of consciousness

These movies now stream out from the optic nerve, one from each eye, and flood the thalamus, that egg-shaped structure in the middle of our heads that serves as a central distribution center for most of our senses. If these streams of visual information can be likened to a large, flowing river, the thalamus can be likened to the beginning of a delta. Once it leaves the thalamus, the information travels along increasingly divided neural streams. Eventually, there will be thousands of small neural tributaries carrying parts of the original information to the back of the brain. The information drains into a large complex region within the occipital lobe called the visual cortex. Put your hand on the back of your head. Your palm is now less than a quarter of an inch away from the area of the brain that is currently allowing you to see this page. It is a quarter of an inch away from your visual cortex.

The visual cortex is a big piece of neural acreage, and the various streams flow into specific parcels. There are thousands of lots, and their functions are almost ridiculously specific. Some parcels respond only to diagonal lines, and only to specific diagonal lines (one region responds to a line tilted at 40 degrees, but not to one tilted at 45). Some process only the color information in a visual signal; others, only edges; others, only motion.

Damage to the region responding to motion results in an extraordinary deficit: the inability to see moving objects as actually moving. This can be very dangerous, observable in the famous case of a Swiss woman we’ll call Gerte. In most respects, Gerte’s eyesight was normal. She could provide the names of objects in her visual field; recognize people, both familiar and unfamiliar, as human; read newspapers with ease. But if she looked at a horse galloping across a field, or a truck roaring down the freeway, she saw no motion. Instead, she saw a sequence of static, strobe-like snapshots of the objects. There was no smooth impression of continuous motion, no effortless perception of instantaneous changes of location. There was no motion of any kind. Gerte became terrified to cross the street. Her strobe-like world did not allow her to calculate the speed or destination of the vehicles. She could not perceive the cars as moving, let alone moving toward her (though she could readily identify the offending objects as automobiles, down to make and license plate). Gerte even said that talking to someone face-to-face was like speaking on the phone. She could not see the changing facial expressions associated with normal conversation. She could not see “changing” at all.

Gerte’s experience shows the modularity of visual processing. But it is not just motion. Thousands of streams feeding into these regions allow for the separate processing of individual features. And if that was the end of the visual story, we might perceive our world with the unorganized fury of a Picasso painting, a nightmare of fragmented objects, untethered colors, and strange, unboundaried edges.

But that’s not what happens, because of what takes place next. At the point where the visual field lies in its most fragmented state, the brain decides to reassemble the scattered information. Individual tributaries start recombining, merging, pooling their information, comparing their findings, and then sending their analysis to higher brain centers. The centers gather these hopelessly intricate calculations from many sources and integrate them at an even more sophisticated level. Higher and higher they go, eventually collapsing into two giant streams of processed information. One of these, called the ventral stream, recognizes what an object is and what color it possesses. The other, termed the dorsal stream, recognizes the location of the object in the visual field and whether it is moving. “Association regions” do the work of integrating the signals. They associate—or, better to say, reassociate—the balkanized electrical signals. Then, you see something.

So, the process of vision is not as simple as a camera taking a picture. The process is more complex and more convoluted than anyone could have imagined. There is no real scientific agreement about why this disassembly and reassembly strategy even occurs.

Complex as visual processing is, things are about to get worse. We generally trust our visual apparati to serve us a faithful, up-to-the-minute, 100 percent accurate representation of what’s actually out there. Why do we believe that? Because our brain insists on helping us create our perceived reality. Two examples explain this exasperating tendency. One involves people who see miniature policemen who aren’t there. The other involves the active perception of camels.

camels and cops

You might inquire whether I had too much to drink if I told you right now that you were actively hallucinating. But it’s true. At this very moment, while reading this text, you are perceiving parts of this page that do not exist. Which means you, my friend, are hallucinating. I am about to show you that your brain actually likes to make things up, not 100 percent faithful to what the eyes broadcast to it.

There is a region in the eye where retinal neurons, carrying visual information, gather together to begin their journey into deep brain tissue. That gathering place is called the optic disk. It’s a strange region, because there are no cells that can perceive sight in the optic disk. It is blind in that region—and you are, too. It is called the blind spot, and each eye has one. Do you ever see two black holes in your field of view that won’t go away? That’s what you should see. But your brain plays a trick on you. As the signals are sent to your visual cortex, the brain detects the presence of the holes and then does an extraordinary thing. It examines the visual information 360 degrees around the spot and calculates what is most likely to be there. Then, like a paint program on a computer, it fills in the spot. The process is called “filling in,” but it could be called “faking it.” Some believe that the brain simply ignores the lack of visual information, rather than calculating what’s missing. Either way, you’re not getting a 100 percent accurate representation.

It should not be surprising that the brain possesses such independent-minded imaging systems. Proof is as close as last night’s dream. But just how much of a loose cannon these systems can be is evidenced in a phenomenon known as the Charles Bonnet Syndrome. Millions of people suffer from it. Most who have it keep their mouth shut, however, and perhaps with good reason. People with Charles Bonnet syndrome see things that aren’t there. It’s like the blind-spot-fill-in apparatus gone horribly wrong. For some patients with Charles Bonnet, everyday household objects suddenly pop into view. For others, unfamiliar people unexpectedly appear next to them at dinner. Neurologist Vilayanur Ramachandran describes the case of a woman who suddenly—and delightfully—observed two tiny policemen scurrying across the floor, guiding an even smaller criminal to a matchbox-size van. Other patients have reported angels, goats in overcoats, clowns, Roman chariots, and elves. The illusions often occur in the evening and are usually quite benign. It is common among the elderly, especially among those who previously suffered damage somewhere in their visual pathway. Extraordinarily, almost all of the patients experiencing the hallucinations know that they aren’t real. No one really knows why they occur.

This is just one example of the powerful ways brains participate in our visual experience. Far from being a camera, the brain is actively deconstructing the information given to it by the eyes, pushing it through a series of filters, and then reconstructing what it thinks it sees. Or what it thinks you should see. Yet even this is hardly the end of the mystery. Not only do you perceive things that aren’t there with careless abandon, but exactly
how
you construct your false information follows certain rules. Previous experience plays an important role in what the brain allows you to see, and the brain’s assumptions play a vital role in our visual perceptions. We consider these ideas next.

Since ancient times, people have wondered why two eyes give rise to a single visual perception. If there is a camel in your left eye and a camel in your right eye, why don’t you perceive two camels? Here’s an experiment to try that illustrates the problem nicely.