Documented Examples...

...on why you should not trust your brain too far!
 

The results below prove that in certain settings (and/or when holding certain preconceptions), our brain often convinces itself it has experienced something very specific - when in fact it hasn't!
 

We normally think of seeing as the taking in of objective reality through our eyes. But is it? How much of what we think of as seeing really comes from without, and how much from within? The visual cortex may have a much more important role than we realise in creating expectations for what we are about to see.
"Seeing is only possible when you know what you're going to see" says Harvard neurologist Pascual-Leone

Words help deterimine what we see

The language we speak affects half of what we see, according to researchers at the University of California, Berkeley, and the University of Chicago.

Eureka Alert
31 Jan 2006

Scholars have long debated whether our native language affects how we perceive reality and whether speakers of different languages might therefore see the world differently. The idea that language affects perception is controversial, and results have conflicted. A paper published this month in the Proceedings of the National Academy of Sciences supports the idea but with a twist.

The paper suggests that language affects perception in the right half of the visual field, but much less, if at all, in the left half. The paper, "Whorf Hypothesis is Supported in the Right Visual Field but not in the Left," by Aubrey Gilbert, Terry Regier, Paul Kay, and Richard Ivry is the first to propose that language may shape just half of our visual world.

Terry Regier is Associate Professor of Psychology at the University of Chicago. Gilbert is a graduate student in the Helen Wills Neuroscience Institute at UC Berkeley. Kay is Professor Emeritus of Linguistics and a senior research scientist at the International Computer Science Institute in Berkeley. Ivry is a Professor of Psychology, director of UC Berkeley's Institute of Cognitive and Brain Sciences, and a member of the Helen Wills Neuroscience Institute.

Their finding is suggested by the organization of the brain, the researchers say. Language function is processed predominantly in the left hemisphere of the brain, which receives visual information directly from the right visual field. "So it would make sense for the language processes of the left hemisphere to influence perception more in the right half of the visual field than in the left half", said Terry Regier of the University of Chicago, who proposed the idea behind the study.

The team confirmed the hypothesis, through experiments designed and conducted in Richard Ivry's lab at the University of California, Berkeley. "We were thrilled to find this sort of effect and are very interested in investigating it further," said Gilbert, the lead author on the study. The hypothesis was confirmed in experiments that tested Berkeley undergraduates, and also in an experiment that tested a patient whose hemispheres had been surgically separated. "The evening I first reviewed the split-brain patient data I called people at home in my excitement to share the findings," said Gilbert.

Many of the distinctions made in English do not appear in other languages, and vice versa. For instance, English uses two different words for the colors blue and green, while many other languages such as Tarahumara, an indigenous language of Mexico instead use a single color term that covers shades of both blue and green. An earlier study by Paul Kay and colleagues had shown that speakers of English and Tarahumara perceive colors differently: English speakers found blues and greens to be more distinct from each other than speakers of Tarahumara did, as if the English "green" / "blue" linguistic distinction sharpened the perceptual difference between the colors themselves. The present study essentially repeated the English part of that earlier test, but also made sure that colors were presented to either the right or the left half of the visual field something the earlier study hadn't done so as to test whether language influences the right half of our visual world more than the left half, as predicted by brain organization.

In each experimental trial of the present study, participants saw a ring of colored squares. All the squares were of exactly the same color, except for an "odd-man-out" of a different color. The odd-man-out appeared in either the right or the left half of the circle, and participants were asked to indicate which side of the circle the odd-man-out was on, by making a keyboard response. Critically, the color of this odd-man-out had either the same name as the other squares (e.g. a shade of "green", while the others were all a different shade of "green"), or a different name (e.g. a shade of "blue", while the others were all a shade of "green"). The researchers found that participants responded more quickly when the color of the odd-man-out had a different name than the color of the other squares as if the linguistic difference had heightened the perceptual difference but this only occurred if the odd-man-out was in the right half of the visual field, and not when it was in the left half. This was the predicted pattern.

Earlier studies addressing the possible influence of language on perception tended to look for a simple yes or no answer: either language affects perception, or it does not. In contrast, the current findings support both views at once. Language appears to sharpen visual distinctions in the right visual field, and not in the left visual field. The researchers conclude that "our representation of the visual world may be, at one and the same time, filtered and not filtered through the categories of language."

Study Verifies Power of Positive Thinking

Your medicine really could work better if your doctor talks it up before handing over the prescription.

Lauran Neergaard
Associated Press
28 November 2005

Research is showing the power of expectations, that they have physical -- not just psychological -- effects on your health. Scientists can measure the resulting changes in the brain, from the release of natural painkilling chemicals to alterations in how neurons fire.

Among the most provocative findings: New research suggests that once Alzheimer's disease robs someone of the ability to expect that a proven painkiller will help them, it doesn't work nearly as well.

It's a new spin on the so-called placebo effect -- and it begs the question of how to harness this power and thus enhance treatment benefits for patients.

"Your expectations can have profound impacts on your brain and your health,'' says Columbia University neuroscientist Tor Wager.

"There is not a single placebo effect, but many placebo effects,'' that differ by illness, adds Dr. Fabrizio Benedetti of Italy's University of Torino Medical School, who is studying those effects in patients with Alzheimer's, Parkinson's disease and pain.

The placebo effect is infamous from studies of new medications: Scientists often given either an experimental drug or a dummy pill to patients and see how they fare. Frequently, those taking the fake feel better, too, for a while, making it more difficult to tease out the medication's true effects.

Doctors have long thought the placebo effect was psychological.

Now scientists are amassing the first direct evidence that the placebo effect actually is physical, and that expecting benefit can trigger the same neurological pathways of healing as real medication does. Among them:

--University of Michigan scientists injected the jaws of healthy young men with salt water to cause painful pressure, while PET scans measured the impact in their brains. During one scan, the men were told they were getting a pain reliever, actually a placebo.

Their brains immediately released more endorphins -- chemicals that act as natural painkillers by blocking the transmission of pain signals between nerve cells -- and the men felt better. To return to pre-placebo pain levels, scientists had to increase the salt-water pressure.

"Our brain really is on drugs when we get a placebo,'' says co-researcher Christian Stohler, now at the University of Maryland. More remarkable, some especially strong placebo responders suggest "many brains can actually stimulate that (pain-relief) system more.''

Italy's Benedetti gave Parkinson's patients a placebo and measured the electrical activity of individual nerve cells in a movement-controlling part of the brain. Those neurons quieted down, a decrease in firing of about 40 percent that correlated with a reduction in patients' muscle rigidity -- they moved more easily.

To further prove the power of belief, Benedetti hooked pain patients to a computerized morphine injection system. Sometimes the computer administered a dose without them knowing it; sometimes a nurse pretended to give it. The morphine was up to 50 percent more effective when patients knew it was coming.

Likewise, Parkinson's patients moved much better when they were told that doctors had turned on a pacemaker-like implant in their brains, which blocks tremors, than when it was turned on covertly.

But in a similar experiment with Alzheimer's patients suffering pain, Benedetti found no difference between covert or expected dosing. The results are preliminary, he cautioned a meeting of the Society for Neuroscience last month. But it appears that because Alzheimer's robs patients of the cognitive ability to expect a benefit, they need higher doses of painkillers to get as much relief as non-demented patients.

Placebos aren't a substitute for real medicine. But the research suggests maybe doctors should try to manipulate patients' treatment expectations, for at least some hard-to-treat conditions.

"The bigger question is how do we capitalize on the placebo effect,'' said Dr. Helen Mayberg of Emory University, whose studies suggest some antidepressants have a "placebo-plus'' activity in the brain. "There may be a phenomenon we all have access to.''

Brand Blink: Understanding the Mind to get to the Heart of Buying Decisions

Malcolm Gladwell enlightens our thinking with his book Blink, a fascinating exploration of how decisions are made in the blink of an eye, before consumers even realize theyre making a decision. He suggests we think without thinking.

By Daryl Travis, CEO, Brandtrust
Oct 2005

Gladwells effort to share emerging insights into how our brains work is timely. In this decade, we are learning more about how humans think and feel and what drives our behavior than the whole of our discoveries in the time since Sigmund Freud dreamt up the idea of psychoanalysis. This has profound implications for marketing and brand professionals. As it turns out, these developments are revealing just how faulty and inadequate conventional research methods are when it comes to truly understanding consumers.

WHATS BEHIND BLINK?
In Blink, Gladwell urges that people make decisions through rapid cognition and a concept known as thin-slicingthe ability of our unconscious to find patterns in situations and behavior based on very narrow slices of experience. More than we realize, we evaluate a situation or a brand and frame our response before we ever consciously think about it. When we thin-slice, we recognize patterns and make snap judgments, we do this process of editing unconsciously. We first see and perceive a color several hundred milliseconds before we can think or say red light. Our foot seeks the brake long before we actually think about stopping, that is, if we think about it at all.

As Gladwell warns, while people are very willing and very good at volunteering information explaining their actions, those explanations, particularly when it comes to the kinds of spontaneous opinions and decisions that arise out of the unconscious, arent necessarily correct. Finding out what people think of a rock song sounds as if it should be easy. But the truth is that it isnt, and the people who run focus groups and opinion polls havent always been sensitive to this fact (Gladwell, 2005, p. 155).

FINDING BLINK
Brains are pattern machines. (Hawkins and Blakeslee, 2004) These patterns make blink moments possible. But, if you are a marketer looking to capitalize on a blink phenomenon, be aware the brain cannot command itself to go into think blink mode. Instead, it involuntarily retrieves from memory the feelings that drive blink encounters. Our brain does not remember exactly what it sees, hears or feels. We dont remember or recall things with complete fidelitynot because the cortex and its neurons are sloppy or error-prone, but because the brain remembers the important relationships in the world, independent of details. (Hawkins, 2004)

The relationships we feel are important in our world are stored as images in our unconscious mind and are linked directly to our emotions. In fact, we dont really think in words, but more in pictures or images. The brain is elegantly designed to store whole concepts within an image. We store memories as images because they are more meaningful and easier to access quickly and automatically. Emotions are largely responsible for creating these memories and are the key to unlocking the meaning within.

It is critical for marketers to understand the role of emotions in human decision making and behavior. Raised in Western culture, we are well indoctrinated in the forces of logic and reason, but weve lost sight of the essential role emotions play in determining human behavior. In fact, all human behavior is driven by emotional input derived from these stored visualizations. There are two systems in the brain. One is for logic and reason. It resides in the neocortex, the outer layer. The other is found in the limbic system, the emotional part of the brain. The emotional components appear in very discreet, well-identified and interconnected regions of the brain. The interconnection occurs in a handful of brain sites that are collectively known as the limbic system. One site in the system, the amygdala, is the brain region responsible for the subjective experience of the emotion. Another site, the hypothalamus, is responsible for triggering the physiological response of the emotion. The hypothalamus, amygdala, and cortex all feed back on each other in a complex alchemy of emotion and reason to coordinate the appropriate behavioral response. This information is also saved and stored by a third member of the limbic system, the hippocampus. All of these brain regions, from the higher cortex to lower limit systems, converge in a single brain region known as the cingulate cortex. It is in the cingulate cortex that decisions are made. Reason and emotion commingle and we are able to coordinate our emotional response to direct our actions and thoughts.

One very important scientific aspect of this whole process is that we know the decision making process does not work in the absence of an emotional signal from the limbic system. Left to its own devices, the consciously thinking part of the brain is incapable of making a decision. The implications of this for marketers are inescapable.

FROM THE HEAD TO THE HEART
Revealing patterns in the brain through a methodology called Emotional Research, a psychoanalytic-based technique designed to tap into memories, makes it possible for consumers to access emotions that drive their behaviors. Through directed relaxation and visualization exercises, consumers can recall experiences and reveal underlying emotions that cannot be accessed via conventional research. Visualization is critical to unlocking the emotional drivers. Jim Hawkins, creator of Palm and Handspring and the founder of the Redwood Neuroscience Institute, discussed this in his provocative book, On Intelligence. The next time you tell a story, step back and consider how you can only relate one aspect of the tale at a time. You cannot tell me everything that happened all at once, no matter how quickly you talk or I listen. You need to finish one part of the story before you can move on to the next. This isnt only because spoken language is serial; written, oral and visual storytelling all convey a narrative in serial fashion. It is because the story is stored in your head in sequential fashion and can only be recalled in the same sequence. You cant remember the entire story at once. In fact, its almost impossible to think of anything complex that isnt a series of events or thoughts (p. 70).

You can easily experience firsthand how Emotional Research works as you read this. Follow these steps as described. First, think about a time and place when you were very relaxed. Close your eyes so you can see it better. In your mind, go to that time and place. Now, scan the scene very slowly from left to right and describe what you are seeing. Notice all the little details. Who is there with you? What time of day is it? What colors do you see? What is the light like? What are you thinking about? What are you feeling?

Now, did you go to the beach or some body of water as we see most of the population do in our research? This is because the desire to be near water is very primal human behavior and a clear indication how this research can powerfully tap into the underlying emotional drivers.

FINDING BRAND BLINK
Emotional Research, like in Brandtrusts Emotional Inquirysm, reveals the elements that create a brand or a blink experience. The directed visualizations of the experiences that first encoded the emotion in a persons memory banks are essential. This unlocks the memories, the emotions and the feelings that influence peoples behavior when faced with a similar experience. For the purpose of brand research, imperfect recall is not an issue. We are simply trying to uncover how the subject feels about a particular experience related to the brand because those feelings drive his or her behavior.

We discover the specific things that actually cause an emotional response related to blink or brand experiences. The sound of your mothers voice, a picture of your grandmothers house, the memory of the loss of a loved one, the aroma of a favorite food, and thousands of other experiences trigger emotional responses.

We also explore the deeper feelings of the emotion and how they invoke behaviors that make up the landscape of all of our psychological experiences. Revealing these emotional responses, common to most people, provides the insights into what a brand must say and do to succeed.

As a result, were confirming brands are about feelings, not facts. Buying decisions are made on promises that transcend products, and promises are rooted in human emotions. Quite simply, brands are built on trust. Making and keeping promises builds trust which is among the most basic of human emotions. To impact our companys bottom line, we need to get in touch with our customers emotions. As marketers, we must have our own blink moments and embrace the reality that branding is about brain surgery and psychology. Because how your customers feel about your brand isnt a casual question. It is the crucial question.

SOURCES:
Gladwell, M. (2005), Blink: The Power of Thinking Without Thinking. New York: Little, Brown and Company.

Hawkins, J. and Blakeslee, S. (2004), On Intelligence: How a New Understanding of the Brain Will Lead to the Creation of Truly Intelligent Machines. New York: Times Books.

Wilson, T. (2002), Strangers to Ourselves: Discovering the Adaptive Unconscious. Boston: Belknap Harvard.

Daryl Travis is CEO of Brandtrust in Chicago (www.brandtrust.com) and author of Emotional Branding: How Successful Brands Gain the Irrational Edge.
 

Insights Into Age-Old Mystery of Geometrical Illusions

The insights provided by neurobiologist Dale Purves and his colleagues over the last few years about why the brain doesn't see the world according to the measurements provided by rulers, protractors or photometers suggest that vision operates in way very different from what most neuroscientists imagine.

By Duke University Medical Center
Sep 29, 2005

In a new book "Perceiving Geometry: Geometric Illusions Explained by Natural Scene Statistics" (Springer), Purves and colleague Catherine Howe explore why the brain generates geometric illusions.

Visual perception is a daunting task for the brain, explains Purves, because light streaming into the eye carries only ambiguous information about the environment.

"The basic problem, recognized for several centuries, is that the image on our retinas can't specify what's out there in the world," said Purves. "The light received by our retinal receptors tangles up illumination, reflectance, transmittance, size, distance and orientation," said Purves. "This means that there's no logical way to get back from the retinal image to what's actually out there in the world."

Nevertheless, many neurobiologists have attempted to explain vision by postulating that the brain's neural wiring can definitively "calculate" the features of a visual scene, despite the visual world's inevitable ambiguity. Such "rule-based" theories, said Purves, have arisen because neurobiologists have concentrated on understanding how neurons in the brain's visual region extract and recognize specific features such as edges in a visual scene.

"Because of the enormous power and success of modern neurophysiology and neuroanatomy, there just didn't seem to be any reason to think much about this issue," said Purves. "However, we began worrying about it seven or eight years ago because the physiology and anatomy people had described didn't explain what we end up seeing. There was no instance, even in the simplest aspects of vision, where the properties of visual neurons in the brain explain the brightness, colors or forms that we actually see."

Thus, Purves and his colleagues began exploring visual illusions -- the name given to the more obvious discrepancies between the physical world and the way people see it -- to understand the strategy the brain uses in perceiving the world. Basically, they statistically compared perceptions -- such as the apparent length of a line -- with physical measurements of what the line stimulus on the retina was most likely to represent in the real world.

This sort of analysis, made by measuring a large set of geometrical images with a device called a laser range scanner, showed that the brain is not a calculating engine, cranking out stimulus features, but a "statistical engine" wired by evolution and a person's experience to make the best statistical guess about objects in a visual scene, based on how successful those guesses have been in the past.

"So, vision is not about extracting features from a scene; it's about extracting statistics in the sense of relating the image on your retina to the visually guided behavior that's worked in the past," said Purves. "This framework for thinking about vision explains quantitatively -- sometimes in amazing detail -- what we end up seeing."

In 2003, Purves and colleague Beau Lotto published an explanation of their "probabilistic" theory of vision in their book "Why We See What We Do: An Empirical Theory of Vision" (Sinauer Associates, Inc).

These two books and dozens of scientific papers have framed the questions that Purves believes researchers must ask about how vision works. But he emphasizes that those questions have only begun to be addressed in neurobiological terms.

"The problem for colleagues in physiology and anatomy is that our theory runs counter to what they've been doing for the last fifty years," said Purves. "And their response has understandably been 'Well, OK, that's interesting. But how do you relate this concept of vision to physiology and this anatomy?' It's perfectly valid to say, 'You've got a nice idea and it does explain the phenomenology of what we see, but how does that relate to the neurons that we know and love?'

"The answer is, we don't know," said Purves. "That's going to be the next many years of vision research. It will mean constructing a framework that explains how neurons and the connections among them operate in service of this complex, evolved statistical process called vision.

"Some bright people will certainly do this in the next ten, twenty or thirty years," said Purves. "I don't expect to be around to see it, but inevitably that will happen. But it's going to take people who deeply understand statistics and computer models of neural systems to develop a working theory of how the properties of neurons and anatomical connections are related to the end product of vision."

Purves said he hopes that the latest book that Catherine Howe and he have written, along with the earlier work, will continue the process of enlisting fellow neurobiologists in tackling the immense question of how we perceive the confusingly ambiguous visual world around us.

Words 'can change what we smell'

A rose by any other name might not smell as sweet, UK research suggests

BBC Online
Sept 05

But labelling an unpleasant smell with a more appealing name can improve its aroma, an Oxford University team has found.

In an experiment, volunteers asked to smell a cheddar cheese odour rated it as more pleasant when it was labelled as "cheddar" than as "body odour".

A label was enough to make them imagine a smell even when they were sniffing clean air, the journal Neuron reports.

Word power

Professor Edmund Rolls and his team scanned the volunteers' brains while they were smelling the test aromas to see what was going on within the brain.

When the cheddar cheese smell was labelled correctly, higher areas of the brain that interpret smells were activated.

How you describe your food could potentially have an important influence on how you perceive it
Professor Rolls

Clean air labelled as cheddar cheese activated the same areas, but to a lesser extent.

But when the cheddar cheese smell or the clean air was labelled as body odour there was no activity in this brain area.

The researchers also checked whether how big a sniff the person took might change the results, which it did not.

Pleasantness of odour

Professor Rolls said: "A word label in our experiment actually influenced the sense of perception of an odour.

"It's the pleasantness of the odour that is being modulated in a part of the brain called the orbito-frontal cortex, which is involved with emotions.

"That high level influence descends down into the olfactory system."

He said the findings could be important for understanding both health and disease.

For example, the orbit-frontal cortex is often damaged in dementia and in people who have had road traffic accidents.

Sometimes, these people have altered appetites as a result that can make them prone to obesity, said Professor Rolls. He said impaired smell processing might be linked to this.

"Of course there is also a consumer side to this. For example, people interested in creating wine and restaurateurs.

"How you describe your food could potentially have an important influence on how you perceive it."

Tim Jacob from the smell research laboratory at Cardiff University said: "Smell is a very special sense.

"It activates systems in the brain which are subconscious.

"Memory has a major impact on smell and we are very suggestible.

"Perfume companies have surveyed potential customers on the smell of perfumes in different coloured and shaped bottles.

"And people think it is a different perfume just because it is in a different bottle even though it is the same smell."

Why we can miss 'obvious' sights
Scientists say they have pinpointed the brain region involved in a curious phenomenon called "change blindness".

BBC Online
24 Aug 2005

Most of us know what it is like to look at something but fail to see the obvious, such as a traffic light turning green.

UK researchers at University College London, along with US colleagues from Princeton University, have located the brain's parietal cortex as key.

Switching this area off causes change blindness, Cerebral Cortex reports.

There has been increasing evidence from brain scan studies to suggest that awareness of what we see is not only down to the part of the brain that processes visual information - the visual cortex - but also other brain regions.

Professor Nilli Lavie and colleagues at UCL focused on an area called the parietal cortex, which is involved with concentration.

Using a process called transcranial magnetic stimulation, which delivers currents to the brain, they were able to temporarily switch off the parietal cortex in nine healthy volunteers.

Visual trickery

When they did this, the volunteers failed to notice big changes in visual scenes, such as when one of four faces on a video screen was replaced by another face.

The exact critical spot in the parietal cortex lies just a few centimetres above and behind the right ear - the area many people scratch when concentration.

The researchers believe their findings explain change blindness, a phenomenon often exploited by magicians.

Professor Lavie said: "The finding that this region of the brain has both these functions, concentration and visual awareness, explains why we can be so easily deceived by, say, a magicians' trick.

"When we're concentrating so hard on something that our processing capacity is at its limits, the parietal cortex is not available to pay attention to new things and even dramatic changes can go unnoticed.

"If you're concentrating on what the magician's left hand is doing, you won't notice what the right hand is doing."

Medical Research Council scientist Dr John Duncan said: "Doubtless, many other parts of the brain are involved."

He said findings such as these might help shed light on medical conditions that can affect a person's perception and attention.

For example, brain damage due to stroke can sometimes mean the individual will completely ignore one side of their body.

Bursting the magic bubble

Psychologists now recognise that magicians know an awful lot about how people perceive the world. Alok Jha finds out how an audience lets itself be tricked

Alok Jha
Thursday July 28, 2005
Guardian

First there's shock tinged with disbelief. A moment of wonder follows. Then, a desperate scramble to rack your brains and work out just how you've been had. There's no denying the effects of a good magic trick. From the great escapes of Houdini and the surreal mental trickery of Derren Brown to the conjurors at children's parties, the appeal is universal.

"Magic's been around for a very long time and it improves over time," says Richard Wiseman, a professor of psychology at Hertfordshire University. "What you're looking at when you see a finished piece of magic is a great deal of expertise, and I think psychologists have a lot to learn from that."

But, not content with just enjoying the tricks, psychologists are now using their effects on the mind to work out how we handle the floods of sensory information coming into our brains and process it into a mental picture of the world around us. Magic is a deception, a disruption of that orderly mental picture where things seem to float in mid-air or coins and cards vanish in front of our eyes. Scientists now believe that, by mapping out how our brains are deceived, they could even help to unlock some of the mysteries of consciousness itself.

"Over the last five years, there's been a reawakening as we look at things like change blindness [a failure to see large changes in a visual scene] and at the fact that consciousness is a construction and may even be an illusion," says Wiseman, himself an accomplished magician and member of the Magic Circle. "Now there's a recognition that magicians are doing something very special."

Some of the founders of modern psychology were fascinated by magicians: throughout the 1890s, Alfred Binet, inventor of the modern IQ test, and Max Dessoir wrote about the ways in which magicians used suggestion and misdirected attention to get their illusions to work. In 1896, Joseph Jastrow published articles in Science on the mechanics of some tricks by contemporary master magicians. But, aside from describing what the magicians were doing, they were at a loss to explain why magic tricks had the effects they did on the audience. As a result, interest in studying the psychology of magic faded for nearly a century.

But, as Wiseman says, a renaissance is now in full swing.

Magic is all about convincing others that the impossible has just happened. And that deception is achieved with a high degree of skill and showmanship.

"We're starting to realise that magicians have a lot of implicit knowledge about how we perceive the world around us because they have to deceive us in terms of controlling attention, exploiting the assumptions we make when we do and don't notice a change in our environment," says Wiseman. "There is an enormous amount of really detailed instruction on how to perform magic. People are always blown away by how detailed a description you'll have."

A card trick that lasts four or five minutes, for example, might have 20 pages of detailed text to describe exactly where to look, what to say, what to do and so on. And a lot of the understanding of a trick has to be from the perspective of the audience.

While the magician's dexterity is important, the audience is also a vital participant in the deception. After all, it is in their minds that the illusion is created. "Magicians seem to be able to carry out secret actions in front of their audience without being spotted. I'm interested in why people don't perceive those actions," says Gustav Kuhn, a psychologist at Durham University.

A simple example of misdirection is used in the coin drop trick. "What you're doing there is pretending to take the coin from one hand to the other but, in fact, leaving it in the original hand," says Wiseman. "What's important is that you're looking where you want the audience to look. You're not looking at the coin, you're looking at the empty hand. In terms of movement, you're moving the hand that doesn't contain the coin to attract people's attention over to that hand."

Another trick, where a magician pretends to throw a ball up in the air, takes the misdirection a step further. "People often experience the ball moving up in the air even though there is no ball present," says Kuhn. They claim to see a ball moving but obviously it's not there so it must be in their mind."

Psychologists can use these tricks to catch a glimpse into how our minds interpret the world around us.

"Magicians are manipulating your consciousness. They are showing you something impossible," says Wiseman. "They're getting you to construct a narrative, which simply isn't true. So that means they know how to make you aware of certain things and blind to other things. What I'm hoping is that magic, this entertainment vehicle that has been around for a long time, will give us a real insight into the deep mysteries of consciousness."

Our brains filter out a huge amount of the mass of sensory input flooding in from our environment. Kuhn explains that we see what we expect to see and what our brains are interested in. "Our visual representation of the world is much more impoverished than we would assume. People can be looking at something without being aware of it. Perception doesn't just involve looking at an object but attending to it."

In Kuhn's recent work, he performed a trick where a cigarette seems to disappear. It involved no sleight of hand or secret. It was a simple case of dropping the cigarette into his lap. "It happens right in front of the spectator's eyes but I misdirect their attention away from the cigarette," says Kuhn.

While his spectators watched, they wore eye trackers (essentially a couple of cameras that monitor eye movement and provide an exact location of where a person is looking in a scene).

It is known that we only receive high-quality information from the area we are fixated on, right in the centre of our field of view. If you stretch out your arm, it is about two thumbs' width at the centre of your vision - everything else is pretty much blurred. The way we compensate for this is to move our eyes around to fill in the gaps and create a better picture of the world around us.

Kuhn's results, to be published in the journal Perception in the next few months, showed that simply staring at the location of the deception was not enough for people to discover how the trick happened.

"People could be looking very close to where the cigarette was being dropped without even seeing it," he says. "Other people were looking quite far away but they did actually did spot the cigarette."

"What it shows is just how much of the picture in our head of our surroundings is a massive construction, based on expectations, what we think is important, what we normally encounter and so on," says Wiseman. "And that's what magicians are very good at exploiting."

Misdirection of an audience, therefore, depends on more than just making people look the wrong way - the truly successful magician misdirects attention. Often, attention is focused on where a person is looking, but this can be manipulated. "You might be looking at a scene and then you hear a voice from the back so your attention is moved towards the back and your processing of visual information will be impaired at the front," says Kuhn.

Verbal suggestion can also play a big role in misdirection. In a recent study, Wiseman looked at how the classic metal-bending tricks, employed by magicians the world over and perhaps made most famous by Uri Geller, used verbal cues. In his experiment, he showed a group of students a video of a trick where a magician bends a key, apparently using his psychokinetic ability (in fact, the bending was done by sleight of hand). The magician then placed the key on a table and the video ended with a static shot of the bent key, which did not bend any further. But a voiceover from the magician at this stage suggested that the key was indeed continuing to bend.

The results, published this year in the British Journal of Psychology, showed that 40% of people claimed to see the key continuing to bend during the static shot at the end of the video. In the control group, where there was no voiceover from the magician, only 5% reported that they saw the key continuing to bend.

Of course, suggestion can take other forms.

"With the ball experiment, we discovered that people aren't just looking up at the ball, they're looking at facial clues to judge where the ball is going to end up," says Kuhn. "If the magician doesn't look up in the air, the trick doesn't work. People feel that they're watching the ball but what they are doing is monitoring the magician's face and cues and using that information to guide their eye movements."

This leads to an interesting idea -could some people be immune to some of the effects of magic? People who suffer from autism, for example, tend to have difficulties gauging facial cues, so their attention is less influenced by where somebody is looking. "You'd expect that somebody who suffered from autism would be more likely to spot the cigarette trick," agrees Kuhn.

The next step is to look at the brain directly. Working with psychologists Tim Hodson and Ben Parris at Exeter University's Centre for Cognitive Neuroscience, Kuhn plans to put people in functional magnetic resonance imaging machines to study which parts of the brain activate when they watch magic tricks.

"We're very interested in the part of the brain that detects cause and effect relations," says Parris.

In particular, the experiments will monitor the dorsal lateral pre-frontal cortex, which is known to be the bit of the brain that registers surprise, and the anterior cingulate, which is activated whenever something incongruous happens in our immediate environment.

Of course, magic is more than just surprise, so the researchers will be looking for something more. "When you're watching magic, there is just a split second when you're in disbelief and that's what we're looking for, that exact moment," he says. "The magic spot."

"No one's done this and it's unclear whether it'll be a single part of the brain or a network," says Parris.

But while psychologists slowly get to grips with the way magicians manage to trick our brains, is there not a risk that the magic will lose its power? That it will cease to be amazing? Wiseman thinks not. "What we get is a more informed audience," he says. "It's a little bit like juggling - you appreciate the juggler more once you've tried to juggle three balls and then you suddenly realise how hard it is to juggle seven."

The research will have benefits for the practitioners of magic, too. "What they will realise is that the human mind is a lot more fallible than we magicians expect," says Kuhn. "Maybe magicians are too careful in the way they conceal their secrets in front of an audience. They can probably get away with quite a bit more."

Science Blog
07/07/2005

The scientists report in this week's issue of the journal Nature on their finding that this principle of novelty-detection operates in many visual environments.

"Apparently our thirst for novelty begins in the eye itself," says Markus Meister, the Jeff C. Tarr Professor of Molecular and Cellular Biology in Harvard's Faculty of Arts and Sciences. "Our eyes report the visual world to the brain, but not very faithfully. Instead, the retina creates a cartoonist's sketch of the visual scene, highlighting key features while suppressing the less interesting regions."

These findings provide evidence that the ultimate goal of the visual system is not simply to construct internally an exact reproduction of the external world, Meister and his colleagues write in Nature. Rather, the system seeks to extract from the onslaught of raw visual information the few bits of data that are relevant to behavior. This entails the discarding of signals that are less useful, and dynamic retinal adaptation provides a means of stripping from the visual stream predictable and therefore less newsworthy signals.

For example, Meister says, in visual environments such as forests or fields of grass with many vertical elements but only rare horizontal features, the retina adjusts to suppress the routine vertical features while highlighting the singular horizontal elements.

Meister and his co-authors examined neural signals in retinal ganglion cells, which convey visual images from the eye to the brain. These cells generally record local spatial differences and changes over time rather than faithful renditions of momentary scenes. Scientists had interpreted this as a form of predictive coding, a strategy shaped by the forces of evolution in adaptation to the average image structure of natural environments.

"Yet animals encounter many environments with visual statistics different from this hypothetical 'average' scene," Meister says. "We have found that when this happens, the retina adjusts its processing dynamically: The spatio-temporal receptive fields of retinal ganglion cells change after a few seconds in a new environment. These changes are adaptive, improving predictive coding by enhancing the ability of these receptive fields to pick out unusual features."

While manipulating the visual scenes faced by salamanders and rabbits, Meister and colleagues recorded neural signals from the animals' retinal ganglion cells, testing whether adaptation to a different environment altered the encoding of retinal signals. From the neural responses to novel stimuli, the researchers computed the sensitivity of individual ganglion cells to various scenes.

For most cells, sensitivity to a novel scene was greater than sensitivity to control scenes to which the animals had already been exposed, a gap that grew gradually in the seconds after introduction to a new environment. Because this adaptation occurred in both salamanders and rabbits, Meister concluded that it typifies retinal function in both amphibians and mammals, animals that differ greatly in ecology and physiology but share the challenge of adjusting to a variable visual environment.

From Harvard University

By BJS
Created 02/01/2005

In this month's issue of the journal Learning & Memory, scientists from Johns Hopkins University report new insights into how such "false memories" are formed. This is the first study to use neuroimaging to investigate how the brain encodes misinformation during the creation of a false memory.

Using advanced, non-invasive imaging techniques, Yoko Akado and Craig Stark compared the areas of the brain that were active when a subject was encoding a complex event and afterwards, during exposure to misleading information. For example, subjects were asked to watch a vignette comprised of 50 photographic slides showing a man stealing a woman's wallet, then hiding behind a door. A little later, the subjects were shown what they thought was the same sequence of slides but unbeknownst to them the second set of slides contained a misleading item and differed in small ways from the original--the man hid behind a tree, for example, not a door.

Two days later, the subjects took a memory test, which asked them to recall details such as where the man hid, and which presentation--the first, second, or both--contained that information. Memory for a misinformation item was scored as a false memory only if the subject attributed the item to either the original presentation or to both the original and second slide presentations.

Stark and Akado found clear evidence that the subjects' brain activity predicted if their memories of the theft would be accurate or false. Consistent with findings from numerous previous studies that have reported that areas such as the hippocampus are highly active during memory formation, Okado and Stark found activity in the left hippocampus tail as well as perirhinal cortex was correlated with successful encoding of an item in memory, even when the memory that was formed was for a false item. But in subjects who had formed false memories, it was noticeable that activity in other brain areas such as the prefrontal cortex was weak during exposure to the second sequence of slides compared to during the original viewing.

Okada and Stark suggest that activity in the prefrontal cortex is correlated to encoding the source, or context, of the memory. Thus, weak prefrontal cortex activity during the misinformation phase indicaates that the details of the second experience were poorly placed in a learning context, and as a result more easily embedded in the context of the first event, creating false memories.

From Cold Spring Harbor Laboratory: www.cshl.org/

By Dr David Whitehouse
BBC News Online science editor

Simply the belief that you are drinking alcohol can impair judgement and dent memory, say researchers.

According to Seema Assefi and Maryanne Garry, two psychologists at Victoria University in New Zealand, memory can be affected by an alcohol placebo.

Tests showed that participants in an experiment who were told they were drinking vodka, but were not, were more swayed by misleading information and more certain their memory was correct than those who were told they were drinking tonic water.

Dr Garry says the research has given new insights into how human memory works and how both social and non-social influences can affect a person's recall of events.

"What we have done is that we have made people's memory worse by telling them that they were intoxicated even though they had drunken nothing stronger than plain flat tonic water with limes," he adds.

Thinking yourself tipsy

For the study, 148 students were split into two groups, half being told they were getting vodka and tonic and the rest told they were getting just tonic. In reality, all were getting just plain tonic.

We found people who thought they were intoxicated were more suggestible and made worse eyewitnesses compared to those who thought they were sober

Seema Assefi

The research was carried out in a bar-like room equipped with bartenders, vodka bottles, tonic bottles, and glasses.

Flat tonic water was poured from sealed vodka bottles to appear genuine. The deception was completed by rimming glasses with limes dunked in vodka.

After consuming their drinks, the students watched a sequence of slides depicting a crime. They also read a summary of the crime that contained misleading information.

"We found people who thought they were intoxicated were more suggestible and made worse eyewitnesses compared with those who thought they were sober," Seema Assefi says.

"In fact the 'vodka and tonic' students acted drunk, some even showing physical signs of intoxication," she adds.

Giggling girls

When told, the sober students reacted with disbelief.

"When students were told the true nature of the experiment at the completion of the study, many were amazed that they had only received plain tonic, insisting that they had felt drunk at the time," she comments.

Dr Garry concludes: "It showed that even thinking you've been drinking affects your behaviour.

"Even on plain tonic water, the male students flirted with Seema as she conducted the experiment and the girls giggled a lot."

The serious point behind the research is that it demonstrates that memory is not just about filing away information like a computer does. It is what we use to understand and remember events in a social setting, such as witnessing a crime.

The research is published in Psychological Science, published by the American Psychological Association.

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3035442.stm

Published: 2003/07/01 17:46:12 GMT

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