Cover; April/May 2007; Scientific American Mind; by Staff Editor; 1 Page(s)

From the Editor; April/May 2007; Scientific American Mind; by Mariette DiChristina; 1 Page(s)

Thoughts of food seem to consume us, weighing heavily on our minds. We hungrily scan the headlines, seeking ways to battle excess pounds. We devour diet advice, to little avail. Despite our good intentions, obesity rates keep climbing. Why is it so hard to stop overeating? "When our stomach begins to growl, too often it drowns out any good advice coming from our brain," writes psychiatrist Oliver Grimm in his article "Addicted to Food?" Any person may have difficulty with restraint at times, as Grimm explains. For binge eaters, the problem intensifies; the brain's reward system can go haywire. In neurobiological terms, binge eating is not dissimilar to drug addiction.

At the other end of the food-behavior scale, a person who has, in effect, too much control over what he or she ingests can suffer from self-imposed starvation. People afflicted with disorders such as anorexia eat too little because their distorted mental image of their body looks larger than reality, explain Christian Eggers and Verena Liebers in "Through a Glass, Darkly." To return to normal weight, anorexics must learn to adjust their flawed perceptions.

Table of Contents; April/May 2007; Scientific American Mind; by Staff Editor; 2 Page(s)

Letters; April/May 2007; Scientific American Mind; by Staff Editor; 2 Page(s)

Your coverage of the psychobiological roots of violence in "The Violent Brain," by Daniel Strueber, Monika Lueck and Gerhard Roth, was interesting and compelling. Although their report seems to be accurate, I find problematic the article's near exclusion of a discussion of social factors involved in violence.

Certainly psychobiology can help explain the behaviors of some chronic violent offenders. Yet these extreme cases are rare; it is far more common to find offenders who commit violence as a result of weak bonds to society, goal frustration or other social problems. In fact, the Dunedin study profiled in the article mentions social factors as a likely reason for continued violence among life-course persistent offenders--not psychobiology.

Head Lines; April/May 2007; Scientific American Mind; by Melinda Wenner, Kurt Kleiner, Kaspar Mossman, Mason Inman, Jonathan Beard, Karen A. Frenkel, Karen Schrock; 7 Page(s)

The good news: as we get older, we become more ambidextrous. The bad news: this new skill develops because the performance of our dominant hand declines so drastically.

Researchers at Ruhr University Bochum in Germany and the California Institute of Technology tested 60 volunteers who described themselves as right-handed. The older the subjects were, the less successful they were at motor performance tests using their dominant hand. Left-hand performance did not deteriorate as drastically with age.

Staving off Dementia; April/May 2007; Scientific American Mind; by Andrew Klein; 2 Page(s)

Marijuana is infamous for its ability to muddle thoughts and dull reactions. What is less well known is that it may also blunt the progression of Alzheimer's disease, which relentlessly robs its sufferers of their memories and personality. Families and individuals tormented by this deterioration may welcome such an alternative therapy, no matter how they feel about marijuana's illegal status.

"I went through several years of a son on marijuana and had him placed in a facility to be 'dried out,'" says Ruth, age 69, of St. Louis. Even so, she says she would consider giving the drug to her 79-year-old husband, Joe, who now suffers from Alzheimer's, if it stopped his combativeness and helped to slow his memory loss. Joe is just one of 4.5 million Americans who have the neurodegenerative disorder, which usually strikes after the age of 60 and is found in nearly half of those older than 85.

I Think, Therefore I Err?; April/May 2007; Scientific American Mind; by S. Alexander Haslam; 2 Page(s)

In Gordium in the fourth century B.C., an oxcart was roped to a pole with a complex knot, and it was said that the first person to untie it would become the king of Asia. Unfortunately, the knot proved impossible to untie. Legend has it that when confronted with this problem, rather than deliberating on how to untie the knot, Alexander simply took his sword and cut it in two--then went on to conquer Asia. Ever since, the notion of a "Gordian solution" has referred to the attractiveness of a simple answer to an otherwise intractable problem.

Among researchers in the psychology of decision making, however, such solutions have traditionally held little appeal. In particular, the "conflict model" of decision making proposed by psychologists Irving Janis and Leon Mann in their 1977 book, Decision Making (Free Press), argued that a complex decision-making process is essential to guarding individuals and groups from the perils of "group-think." Decisions made without thoroughly canvassing, surveying, weighing, examining and reexamining relevant information and options would be suboptimal and often disastrous. The Kennedy administration's calamitous decision to invade the Bay of Pigs in 1961 is typically held up as an example of such perils, whereas its successful handling of the Cuban missile crisis in 1962 is cited as an example of the advantages of careful deliberation.

Illusions: Paradoxical Perceptions; April/May 2007; Scientific American Mind; by Vilayanur S. Ramachandran and Diane Rogers-Ramachandran; 3 Page(s)

Paradoxes--in which the same information may lead to two contradictory conclusions--give us pleasure and torment at the same time. They are a source of endless fascination and frustration, whether they involve philosophy (consider Russell's paradox, "This statement is false"), science--or perception. The Nobel Prize winner Peter Medawar once said that such puzzles have the same effect on a scientist or philosopher as the smell of burning rubber on an engineer: they create an irresistible urge to find the cause. As neuroscientists who study perception, we feel compelled to study the nature of visual paradoxes.

Let us take the simplest case. If different sources of information are not consistent with one another, what happens? Typically the brain will heed the one that is statistically more reliable and simply ignore the other source. For example, if you view the inside of a hollow mask from a distance, you will see the face as normal--that is, convex--even though your stereovision correctly signals that the mask is actually a hollow, concave face. In this case, your brain's cumulative experience with convex faces overrides and vetoes perception of the unusual occurrence of a hollow face.

Calendar; April/May 2007; Scientific American Mind; by Staff Editor; 1 Page(s)

Listening with Your Eyes; April/May 2007; Scientific American Mind; by Christoph Kayser; 6 Page(s)

It is Saturday evening at the state fair. To your left, "Rock around the Clock" wafts out of a tent. Behind you, a group of teenagers is carrying on, laughing loudly. Somewhere, an infant is crying. A profusion of neon signs and blinking lights competes for your attention. A roller coaster plummets and makes a hairpin curve. Your senses are already overloaded. But the experience wouldn't be complete without an ice-cream cone in hand and the aroma of cotton candy and honey-roasted almonds in the air.

A scene like this busy fair illustrates just how many signals bear in on us simultaneously from the environment. Yet our brain is able to integrate all the stimuli and make sense of the cacophony of movement and sound. Exactly how this integration happens is not yet understood--which naturally piques the curiosity of neuroscientists.

Through a Glass, Darkly; April/May 2007; Scientific American Mind; by Christian Eggers and Verena Liebers; 6 Page(s)

They all look the same in front of the mirror--attractive and slim--but one after another, they get up in swimsuits and bemoan their physical faults: fat thighs, shapeless silhouettes, flat chests. These young women are participating in group sessions focused on body image, co-sponsored by the universities of Bochum and Mainz in Germany. Senior therapist Silja Vocks knows she will have a hard time getting through to these girls, who all suffer from eating disorders, but it is her job to help them learn to like themselves again.

Eating disorders are complex psychiatric conditions, instigated by a number of factors both inborn and circumstantial. For most patients, however, significant mental pain stems from having a faulty body image, a term psychologists use to describe an individual's internal picture of his or her exterior form. In truth, this image more accurately reflects self-esteem than physical appearance. It is based not so much on fact as on emotion, and the opinions of family and peers, as well as cultural ideals, can dramatically alter its dimensions.

Addicted to Food?; April/May 2007; Scientific American Mind; by Oliver Grimm; 4 Page(s)

It's been a long day, and you are still at the office. With your blood sugar plummeting, your brain starts to obsess: Where can I get some food? You gather your money and dash across the street to the fast-food place. But as you bite into the greasy burger, your conscience suddenly kicks in: What am I doing?

It is a common scenario for many of us. Hunger is a potent, if only temporary, condition that can overpower our very best nutritional intentions. In its absence, the brain's cerebrum--governing conscious behavior--helps us make healthy, informed decisions about what we eat. But when our stomachs begin to growl, too often they drown out any good advice coming from our brains. Unfortunately, the short-sighted decisions we make with our stomachs are having an increasingly negative effect on our health.

Freeing a Locked-In Mind; April/May 2007; Scientific American Mind; by Karen Schrock; 6 Page(s)

The patient opens her eyes, but they are unfocused. She is awake yet apparently unaware of anything going on in the hospital room around her. After the accident, she lies in her bed, unresponsive, day after day. What is she thinking?

Soon we may be able to communicate with such "locked-in" minds--trapped in bodies that no longer respond to their mental control. In a blitz of publicity last fall, a team of British researchers announced they had imaged the brain of one of their "vegetative" patients and discovered that she was in fact conscious and aware. Now that same team has developed a way to ask yes-or-no questions of such patients. The idea is radical: we might soon be able to reach a number of people, including 250,000 Americans, who suffer from consciousness disorders--patients who, until now, had been considered beyond treatment.

The Pain Gate; April/May 2007; Scientific American Mind; by David Dobbs; 8 Page(s)

For most of the 140 years since it was named, the disorder known as burning man syndrome has operated in near-total obscurity. Even today it afflicts perhaps 200 to 500 people in all of North America and a few thousand worldwide. Until about three years ago, essentially all medical knowledge about it was contained in its name, erythromelalgia, which translates as "painful red extremities." Few doctors knew of it, only a handful had seen it, and none knew what caused it or how to treat it. At any given time, the few thousand people who had it suffered its torment--searing heat in the feet and lower legs and sometimes in the hands--without understanding why. Most thought they were completely alone.

Pam Costa, 42, lived her first decade this way. She is one of perhaps 30 or 40 people in the U.S., and possibly 200 to 500 worldwide, known to have an inherited form of the disease.

The Myth of the Teen Brain; April/May 2007; Scientific American Mind; by Robert Epstein; 8 Page(s)

It's not only in newspaper headlines--it's even on magazine covers. TIME, U.S. News & World Report and even Scientific American Mind have all run cover stories proclaiming that an incompletely developed brain accounts for the emotional problems and irresponsible behavior of teenagers. The assertion is driven by various studies of brain activity and anatomy in teens. Imaging studies sometimes show, for example, that teens and adults use their brains somewhat differently when performing certain tasks.

As a longtime researcher in psychology and a sometime teacher of courses on research methods and statistics, I have become increasingly concerned about how such studies are being interpreted. Although imaging technology has shed interesting new light on brain activity, it is dangerous to presume that snapshots of activity in certain regions of the brain necessarily provide useful information about the causes of thought, feeling and behavior.

Chips in Your Head; April/May 2007; Scientific American Mind; by Frank W. Ohl and Henning Scheich; 6 Page(s)

As many as 400,000 Americans are partially or totally paralyzed from spinal cord injuries, which interrupt the nerve cell signals relaying information between the brain and the body. Others lose the ability to move and communicate because of neurodegenerative disorders such as amyotrophic lateral sclerosis, or Lou Gehrig's disease, which causes the neurons controlling muscles to die. Still half a million more Americans suffer profound sensory deficits such as blindness or deafness. For more than a century, scientists have sought some type of electrical replacement for lost motor and perceptual functions to alleviate these conditions.

Only recently, however, have researchers and doctors begun testing such neuroprostheses in humans. Existing prosthetic instruments transmit signals from areas in the body to the brain--cochlear implants in the inner ear, for example, can send signals to the auditory nerve to enable hearing. The next generation of devices, however, will move into the brain itself. Various research teams are now building so-called brain-computer interfaces (BCIs), which help to restore paralyzed patients' ability to communicate and move by translating neuron signals in their brains into commands that control computer cursors or robots. And a new wave of brain implants, including a type developed in our laboratory in Germany, is poised to transfer information into the brain, thereby reviving sensory function.

Lithium's Healing Power; April/May 2007; Scientific American Mind; by Jochen Paulus; 6 Page(s)

Ever since her senior year in high school, Kay Redfield Jamison has spent days and even weeks exploding with energy. She would stay up all night, sometimes for weeks in a row, feeling euphoric and productive. She would become lively, extroverted and impulsive. She would make bizarre purchases--a stuffed fox one day and a dozen snakebite kits the next.

Then, suddenly, it would end, and Jamison would descend into darkness. She would lose interest in work, friends and hobbies. She would feel listless, drained and totally alone. During these periods, thoughts of death and decay plagued her. More than once, she flirted with suicide. "From the time I woke up in the morning until the time I went to bed at night, I was unbearably miserable and seemingly incapable of any kind of joy," she wrote in her memoir, An Unquiet Mind (Alfred A. Knopf, 1995).

A Personal Obsession; April/May 2007; Scientific American Mind; by Isabel Wondrak and Jens Hoffmann; 6 Page(s)

One day recently Helene K., a 50-year-old occupational therapist, received a call at home from a former patient. It took her several minutes to remember the man, who had been discharged from her clinic more than a year earlier. He said he would like to see her again, but Helene firmly rejected the idea: she wanted no further contact with him.

Then came more phone calls from the man, as well as letters declaring his love for her. One morning Helene opened her front door and saw the man standing there, suitcase in hand; he had resigned from his job and wanted to move in with her. Helene demanded that he leave her alone, but instead he began following her everywhere.

Autism: An Epidemic?; April/May 2007; Scientific American Mind; by Scott O. Lilienfeld and Hal Arkowitz; 2 Page(s)

If the figure of "one in 166" has a familiar ring, perhaps that's because you recently heard it on a television commercial or read it in a magazine. According to widely publicized estimates, one in 166 is now the proportion of children who suffer from autism. This proportion is astonishingly high compared with the figure of one in 2,500 that autism researchers had accepted for decades. Across a mere 10-year period--1993 to 2003--statistics from the U.S. Department of Education revealed a 657 percent increase in the nationwide rate of autism.

Not surprisingly, these bewildering increases have led many researchers and educators to refer to an autism "epidemic." Representative Dan Burton of Indiana also declared in 2001 that "we have an epidemic on our hands." But what's really going on?

Mind Reads; April/May 2007; Scientific American Mind; by Kurt Kleiner, Nicole Branan, Ken Silber; 2 Page(s)

Almost from the time electricity was discovered, scientists suspected it was involved in human and animal motion. They used electricity to make frogs' legs jump and, less successfully, to try to reanimate the dead.

Today modern science can use a judicious jolt of electricity to restart a stopped heart under the right circumstances. Much more difficult has been the attempt to use implanted electrodes to restore function to body parts affected by nerve damage.

Ask the Brains; April/May 2007; Scientific American Mind; by Andrea Halpern, Mark A. W. Andrews; 1 Page(s)

Tunes that get stuck in the head, evocatively called "earworms," are probably related to the more common experience of simply being able to call up from memory any familiar tune. For instance, try thinking of a song you know, such as "Happy Birthday." Most people I test in my lab claim they can do this easily, and the resulting auditory image is fairly vivid. Other scientists and I have been investigating the characteristics of these auditory images and how the brain processes them, which could help explain why some of these images replay persistently.

Familiar tunes that are stored in memory seem to retain characteristics--such as tempo or pitch--that closely match those of their real auditory counterparts. But what is your brain actually doing when you recall a song? My colleagues and I have asked people to carry out tasks involving musical imagery while we recorded their brain activity using neuroimaging. In one study we played sounds of different musical instruments and asked subjects to rate them for similarity. Then we turned off the speakers and asked people simply to imagine the instrument sounds to compare them. We saw similar brain activity in the two conditions: some parts of the auditory system were active both while hearing music and while imagining it, even though the imagined condition was silent.

Head Games; April/May 2007; Scientific American Mind; by Abbie F. Salny; 1 Page(s)

Fill in the blanks surrounding the letters I C E D, according to the clues.

Each letter stands for a different digit. Determine their values to make all five of the equations true.