Seven Signs of Decline

Neurologists now determine if a patient has Alzheimer’s disease by giving the patient a memory test and then taking an extensive medical history, talking to the family and performing tests to eliminate other possible causes for the cognitive lapses. In this way, doctors accurately diagnose Alzheimer’s 90 percent of the time, especially with older patients, according to Nechama Bernhardt, a neurologist in Baltimore specializing in Alzheimer’s. Here are some of signs of the memory loss and confusion that characterize the disorder:

• Asking the same questions repeatedly.

• Repeating the same story word for word multiple times.

• Forgetting how to do basic tasks that the person once performed easily, such as cooking, making repairs and playing cards.

• Problems paying bills or balancing a checkbook (assuming these tasks were not previously difficult).

• Getting lost in familiar places.

• Neglecting personal hygiene habits such as bathing or dressing in clean clothes while insisting on having taken a bath or put on a new outfit.

• Relying on someone else to make decisions—such as what to buy at a supermarket or where to go next—that were easily handled in the past.

None of the symptoms above—alone or even in combination—is a sure sign of the disease. But anyone who displays several of these abnormal behaviors should see a specialist for a more thorough examination.


Source of Information : Scientific American Mind November-December 2009

The Benefits of Worry

If worry is an integral part of what makes us human, can it also serve a positive function? Psychologist Graham Davey of the University of Sussex in England was one of the first experts to suggest potential plus sides to worry. In a 1994 study Davey explored a range of consequences stemming from this natural tendency; he found people reported that although fretting can make things worse, it can also be constructive, helping to motivate them to take action, resolve problems and reduce anxiety.

More recent research supports the idea that elevated levels of worry can improve performance. In 2005 psychologist Maya Tamir, then at Stanford University, showed that neurotic students were more likely to believe that increasing their level of worry when working on a cognitively demanding task, such as a test, would allow them to excel. Worrying before the test indeed helped the more neurotic individuals do better, whereas the pretest level of worry did not particularly influence the overall experience or outcomes for the less neurotic participants. Not only can worry benefit performance, but it may also encourage action. A 2007 study in the journal Cognition and Emotion revealed that smokers may be more convinced to quit if they worry about the risks of smoking. The promising results prompted the study authors to suggest potential strategies, such as having doctors remind smokers about the downsides, capitalizing on the worry-motivation relationship to encourage smokers to dispense with cigarettes.

Although it is difficult to determine the precise line between healthy, beneficial worry and unhealthy, detrimental worry, Michel Dugas, a psychologist at Concordia University in Montreal, likes to think of worry as a bell curve whereby moderate levels are associated with improved functioning, but excess levels are associated with a decline in performance.

Christine Calmes, a postdoctoral fellow at the VA Capitol Mental Illness Research, Education and Clinical Center in Baltimore, believes that successful people operate a little higher on the worry scale. As long as fretting doesn’t get the better of someone, it can work to his or her advantage. “It’s all about how people cope with the worry,” Calmes says. “If it’s incapacitating, then it’s not okay. But if worrying motivates people to go above and beyond—put in longer hours, attend to details that others may miss—then it’s a good thing.”

Source of Information : Scientific American Mind November-December 2009

Why We Worry - Stunted Emotions

Although worry hijacks aspects of our emotional circuitry, chronic worriers seek to control their emotions—and their fretting does tend to numb emotional responses. For instance, it is fairly well established that damage to the frontal lobe—which, as the Boston University study showed, has been demonstrated to be more active in worriers who are thinking about the future—is associated with blunted, or an absence of, emotions. In another emotion-damping mechanism, several studies have confirmed that excess fretting reduces activity in the sympathetic nervous system in response to a threat. This branch of the nervous system normally allows the body to react quickly to impending danger by accelerating breathing and also increasing heart rate to oxygenate muscles to fight or flee.

In one classic study from 1990 Borkovec showed by observing heart rates how worry can dull emotional reactions. He found that people with anxiety about public speaking did not experience variations in their heart rate when relaxing, remaining neutral (that is, neither worrying nor relaxing) or engaging in worry before viewing scary images. After seeing the images, however, subjects in the worry group displayed significantly less variation in heart rate than those in the neutral or relaxed condition, despite reporting feeling more fearful.

At the same time, worry hinders a person’s physical reaction to a threat by amplifying activity in the parasympathetic nervous system. When working properly, this part of the nervous system quiets the body as it recovers from a stressful experience. I experienced this system in operation when I participated in a study in Mennin’s laboratory at Yale. The scene was a lone arm suspended in midair. A hand carrying a razor started slicing it. Blood seeped out of the wound as the razor dug deeper, exposing a mass of blood and cartilage. I wanted nothing more than to look away. Amelia Aldao, the Ph.D. student conducting the experiment, wanted to measure my physiological reaction to various film segments, each one meant to elicit a distinct emotion (for instance, disgust in the case of the mutilated arm).

Aldao recorded with electrocardiography how I dealt with a variety of emotions (this Yale study was the first to expand beyond fear), removed the electrodes from my body and led me into the adjacent room. She did some quick calculations on her computer and out popped a few of my stats. Good news. My heart rate variability was high, and my average heart rate measured about 58 beats per minute. These values indicated that my heart could cope well with intense emotions.

In contrast, by consciously trying to be ready for the worst, worriers are actually compromising their body’s ability to react to a truly traumatic event. In 2006 researchers at Columbia University, the National Institute on Aging and Leiden University in the Netherlands reviewed more than two dozen studies and found that overworrying can tax the body and promote cardiovascular problems. Overall, increased worry was associated with an elevated resting heart rate but low heart rate variability Excessive worriers and GAD patients experienced lower heart rate variability during periods of worry; in other words, their hearts returned to a resting rate more slowly than those of healthy worriers did. Prolonged periods of stress even weakened participants’ endocrine and immune function. Some studies reported that excess worry is linked to elevated levels of the stress hormone cortisol, which slows immune responses and may make chronic worriers more susceptible to disease.

Source of Information : Scientific American Mind November-December 2009

Relax! Here’s How

Simple tips and tricks you can use to cope with the stresses of everyday life.

1. Identify productive and unproductive worry
First, determine whether your worries will help you find practical solutions to a dilemma. If “yes, my worries can be constructive,” write a to-do list with explicit steps to help solve the problem. If the answer is “no, my worries are not helping me,” use some of the techniques below to help deal with unproductive worries.

2. Keep an appointment with your worries
Write down your unproductive worries throughout the day and set aside a chunk of time, say 6 to 6:30 p.m., dedicated specifically to thinking about them. By 6, “you may find you’re not interested in those worries anymore,” Leahy says. “Many people find that what they thought they needed an answer to earlier, they don’t care about later in the day.”

3. Learn to accept uncertainty
Worriers have a hard time accepting they can never have complete control in their lives. Leahy says that quietly repeating a worry for 20 minutes (“I may never fall asleep” or “I could lose my job”) reduces its power. “Most people get bored by their worries and don’t even make it to 20 minutes,” he notes.

4. Be mindful
Mindfulness, a technique based on Buddhist teachings, preaches staying in the present moment and experiencing all emotions even when they are negative. Leahy explains there are ways to be mindful throughout your day, while deeply immersed in your favorite song or in conversation with friends. Try living in the now by practicing deep breathing. Let your body relax and the tension in your muscles melt away.

5. Reframe your worry
What happens if a worry comes true? Could you survive losing your job or being dumped? Reframing how you evaluate disappointments in life can take the sting out of failure, Leahy says. Create a positive spin by asking yourself what you have learned from your bad experiences. Make a list of things for which you are grateful.

6. Put worries in perspective
Examine past worries. Do you have a hard time remembering what they are? Very likely this means that those worries never came true or that you were able to cope and forget, Leahy says.


Source of Information : Scientific American Mind November-December 2009

Why We Worry - Craving Control

Worry began to draw the attention of researchers about 25 years ago, when they started to finetune their understanding of the spectrum of anxiety related pathologies. In the early 1980s psychologist Thomas Borkovec of Pennsylvania State University, a pioneer in this field, became interested in the trait while investigating sleep disorders. He found that intrusive cognitive activity at bedtime— worrying—was a factor in insomnia.

By 1990 Borkovec and his colleagues developed the Penn State Worry Questionnaire, a diagnostic tool that helped researchers show excessive fretting to be a feature of all anxiety disorders, especially generalized anxiety disorder (GAD). Psychologists revised the official psychiatric guidelines (then the Diagnostic and Statistical Manual of Mental Disorders III) to reflect this understanding, calling worry the cardinal feature of GAD and making chronic worry a recognized mental health problem. It is now known to affect 2 to 3 percent of the U.S. population, according to the National Institute of Mental Health. Borkovec defined three main components of garden-variety worry: overthinking, avoidance of negative outcomes and inhibition of emotions. Mennin explains that worry piggybacks on humans’ innate tendency to think about the future: “they crave control.” He says “chronic worriers see the world as an unsafe place and want to fight this sense of unrest.”

Overworriers feel that fretting gives them this control, and they tend to avoid situations they can’t have power over. In a 1995 study Borkovec found that people agonized about matters that rarely occurred. The participants, nonetheless, often reported that they believed the overthinking about a possible negative event had prevented it from taking place. Unsurprisingly, worriers show increased activity in areas of the brain associated with executive functions, such as planning, reasoning and impulse control. In 2005 psychologist Stefan Hofmann of Boston University used an electroencephalogram (EEG) to measure activity in the prefrontal cortex, before and after 27 undergraduates were told to give a speech in public. He confirmed previous evidence that activity in the left frontal cortex increases for people who worry compared with those who do not, suggesting that the left frontal cortex plays a prominent role in worrying. Trying too hard to be in command of a given situation or their own thoughts may backfire when worriers are instead overrun with repetitive apprehensions.

Research shows that the more we dwell on negative thoughts, the more those threats feel real and the more they will repeat in our skulls, sometimes uncontrollably. In 1987 Daniel M. Wegner, a psychologist at Harvard University, found that when people were told not to think about a white bear, they tended to mention it about once a minute. In the experiment, Wegner left a participant in a room with a microphone and a bell and asked the volunteer to talk freely about any topic. At one point, he interrupted the person’s monologue and told him to continue talking— but this time, not to think of a white bear. If the subject did think of a white bear, he had to ring the bell. On average, people rang the bell more than six times in the next five minutes and even said “white bear” out loud several times. “By trying to put a worry or a thought out of our mind, it only makes the worry worse,” Wegner says. “Just like when a song gets stuck in your head, you think you ought to be able to get rid of it, but you only end up making it stick more by trying to push it away.” Two mental processes may be at play here, according to Wegner. First, by consciously looking for distractions from the white bear (or your nagging worry), you remain somewhat aware of the undesired thought. The second reason suppression fails is that often you are making an unconscious effort to catch yourself thinking of the forbidden thought, ultimately sensitizing your brain to it.

Two emotion-processing areas of the brain are also involved in worry: the anterior insula and the amygdala. A 2008 Psychological Science study that used functional MRI found that when participants anticipated losing a significant amount of money in the future, activity increased in their anterior insula. That area not only becomes more active in response to worry, but the inclination to worry is also reinforced, because people believe that the act helps them avoid potential losses. The researchers concluded that sometimes, when it comes to making daring monetary decisions, overthinking may turn out to be a good thing.

In 2009 Jack Nitschke, a clinical psychologist at the University of Wisconsin–Madison School of Medicine and Public Health, reported using fMRI to measure activity in the amygdala while GAD patients and healthy subjects viewed pictures of items that were negative (for instance, mutilated bodies) or neutral (say, a fire hydrant). A few seconds before seeing the images, patients received a cue to let them know whether to expect a negative or neutral photograph. Although GAD and healthy subjects experienced no difference in amygdala activation when shown either type of picture, GAD patients displayed unusually high levels of amygdala activity to both negative and neutral cues—suggesting that merely anticipating the possibility of something negative in the future recruits specific neural circuitry, Nitschke says.

Source of Information : Scientific American Mind November-December 2009

Boosting Healthy Brains

The latest research into the neural roots of intelligence may lead to better drugs and tools for cognitive enhancement. In the future, drugs may enhance the neurotransmitters that regulate communication among the salient brain areas underlying general intelligence or more specific mental abilities. Other drugs could stimulate gray matter growth or white matter integrity in relevant areas. Certainly such advances would be welcome as potential treatments for mental retardation and developmental disabilities. They may also be welcome by any individual looking for more intelligence. If an effective “IQ pill” becomes available, are the societal and ethical issues the same as for performance-enhancing drugs in sports, or is there a moral imperative that more intelligence is always better than less? Apparently, many scientists agree with the latter. An online survey of 1,427 scientists conducted in 2008 by Nature found that 20 percent of respondents already use prescription drugs to enhance “concentration” rather than for treating a medical condition. Almost 70 percent of 1,258 respondents who answered the question said they would be willing to risk mild side effects to “boost their brainpower” by taking cognition-enhancing drugs. Eighty percent of all the scientists who responded— even those who did not use these drugs—defended the right of “healthy humans” to take them as work boosters, and more than half said their use should not be restricted, even for university entrance exams. More than a third said that they would feel pressure to give their children such drugs if they knew other kids at school were also taking them. Few appear to favor the “ignorance is bliss” position. Intelligence is a critical resource for the development of civilization. As the global economy evolves and small countries compete with larger countries, assessing, developing and even enhancing intellectual talent may well become the neuroscience challenge for the 21st century.

Source of Information : Scientific American Mind November-December 2009

The Neural Roots of Intelligence

Brain-imaging studies reveal many areas in which the amount of gray matter (neuron bodies) correlates with intelligence test scores. The color patches above indicate the approximate location of the Brodmann areas—structural groupings of neurons numbered according to historical tradition. The letters on each Brodmann area indicate which intelligence factors it is associated with: general (g); spatial (s); and crystallized (c), or factual knowledge. Every individual has a unique pattern of gray matter in these areas, giving rise to different cognitive strengths and weaknesses. Fourteen of the Brodmann areas (colored orange above) are consistently implicated in studies of intelligence-related brain structure and function. Neuropsychologist Rex E. Jung of the University of New Mexico and I reviewed the studies and identified this network, calling it the parieto-frontal integration theory (P-FIT ) because areas in the parietal (green) and frontal (blue) lobes were consistent across the most studies. Most of the P-FIT areas are involved in computation (frontal areas) and sensory integration (parietal areas), the processing and conscious understanding of sensory information.

Source of Information : Scientific American Mind November-December 2009

Consciousness Redux - The Will to Power

Neurosurgeons evoke an intention to act

Surely there must have been times in high school or college when you laid in bed, late at night, and wondered where your “free will” came from? What part of the brain—if it is the brain—is responsible for deciding to act one way or another? One traditional answer is that this is not the job of the brain at all but rather of the soul. Hovering above the brain like Casper the Friendly Ghost, the soul freely perturbs the networks of the brain, thereby triggering the neural activity that will ultimately lead to behavior. Although such dualistic accounts are emotionally reassuring and intuitively satisfying, they break down as soon as one digs a bit deeper. How can this ghost, made out of some kind of metaphysical ectoplasm, influence brain matter without being detected? What sort of laws does Casper follow? Science has abandoned strong dualistic explanations in favor of natural accounts that assign causes and responsibility to specific actors and mechanisms that can be further studied. And so it is with the notion of the will.



Sensation and Action
Over the past decade psychologists such as Daniel M. Wegner of Harvard University amassed experimental evidence for a number of conscious sensations that accompany any willful action. The two most important are intention and agency. Prior to voluntary behavior lies a conscious intention. When you decide to lift your hand, this intention is followed by planning of the detailed movement and its execution. Subjectively, you experience a sensation of agency.

You feel that you, not the person next to you, initiated this action and saw it through. If a friend were to take your hand and pull it above your head, you would feel your arm being dragged up, but you would not feel any sense of being responsible for it. The important insight here is that the consciously experienced feelings of intention and agency are no different, in principle, from any other consciously experienced sensations, such as the briny taste of chicken soup or the red color of a Ferrari. And as a plethora of books on visual illusions illustrate, often our senses can be fooled—we see something that is not there. So it is with the sensation of intentionality and agency. Decades of psychology experiments—as well as careful observation of human nature that comes from a lifetime of living—reveal many instances where we think we caused something to happen, although we bear no responsibility for it; the converse also occurs, where we did do something but feel that something or somebody else must have been responsible. Think about the CEO of a company who takes credit— and bonuses worth many millions—if the stock market price of his company rises but who blames anonymous market forces when it tanks. It is a general human failing to overestimate the import of our own actions when things go well for us. Lest there by any misunderstanding: the sensations of the intention to act and of agency do not speak to the metaphysical debate about whether will is truly free and whether that even is a meaningful statement. Whether free will has some ontological reality or is entirely an illusion, as asserted forcefully by Wegner’s masterful monograph, does not invalidate the observation that voluntary actions are usually accompanied by subjective, ephemeral feelings that are nonetheless as real as anything else to the person who experiences them.



Telling Clues from Surgeries
The quiddity of these sensations has been strengthened considerably by neurosurgeons.
During certain types of brain surgery, neural tissue must be removed, either because it is timorous or because it gives rise to epileptic seizures. How much tissue to remove is a balancing act between the Scylla of leaving remnants of cancerous or seizure-prone material and the Charybdis of removing regions that are critical for speech or other near-essential operations. To probe the function of nearby tissue, the neurosurgeon stimulates it with an electrode that passes pulses of current while the patient—who is awake and under local anesthesia to minimize discomfort—is asked to touch each finger successively with the thumb, count backwards or do some other simple task.

During the course of such explorations in 1991, neurosurgeon Itzhak Fried, now at the University of California, Los Angeles, and his colleagues stimulated the presupplementary motor area, part of the vast expanse of cerebral cortex that lies in front of the primary motor cortex. Activation of different parts of the motor cortex usually triggers movements in different parts on the opposite side of the body, for example, the foot, leg, hip, and so on. The medical team discovered that electrical stimulation of this adjacent region of cortex can, on occasion, give rise to an urge to move a limb. The patient reports that he or she feels a need to move the leg, elbow or arm.

This classical account was elaborated on by a recent study from Michel Desmurget and his colleagues at the Center for Cognitive Neuroscience in Bron, France, that was published in the international journal Science. Here it was electrical stimulation of the posterior parietal cortex, gray matter involved in the transformation of visual information into motor commands—as when your eyes scan the scene in front of you and come to rest on the movie marquee—that could produce pure intentions to act. Patients made comments (in French) such as “It felt like I wanted to move my foot. Not sure how to explain,” “I had a desire to move my right hand,” or “I had a desire to roll my tongue in my mouth.” In none of these cases did they actually carry out the movement to which they referred. But the external stimulation caused an unambiguous conscious feeling of wanting to move. And this feeling arose from within, without any prompting by the examiner and not during sham stimulation. This was different from the cortical sector explored by the earlier Fried study.

One difference between the two stimulated regions was that, at higher current levels, the patient actually moved the limb when the target site was the presupplementary motor area. Parietal stimulation, on the other hand, could trigger a sensation that actual movement had occurred, yet without any motion actually occurring (illusion of movement).

The take-home lesson is that the brain has specific cortical circuits that, when triggered, are associated with sensations that arise in the course of wanting to initiate and then carry out a voluntary action. Once these circuits are delimited and their molecular and synaptic signatures identified, they constitute the neuronal correlates of consciousness for intention and agency. If these circuits are destroyed by a stroke or some other calamity, the patient might act without feeling that it is she who is willing the acting! In the debate concerning the meaning of personal freedom, these discoveries represent true progress, beyond the eternal metaphysical question of free will that will never be answered.

Source of Information : Scientific American Mind November-December 2009

Morning Sickness Tied to Smart Kids

Hormone levels link vomiting and intelligence

A new study shows a correlation between nausea and vomiting during pregnancy and the long-term neurocognitive development of those kids. Pediatric researcher Irena Nulman and her team at the Hospital for Sick Children in Toronto found that youngsters whose mothers suffered from morning sickness during pregnancy scored higher on some cognitive tests than did those whose mothers did not start their pregnant days throwing up. All children tested within the normal range, however. One possible explanation could be differing hormone levels, Nulman says. According to one hypothesis, vomiting reduces caloric intake, decreasing insulin secretion. Low insulin, in turn, boosts levels of other hormones that are known to play a role in the development of a healthy placenta and a healthy blood supply to growing brains.

Source of Information : Scientific American Mind November-December 2009

Evolving Mental Maps

Researchers continue to probe the limits of the brain’s plasticity

We all carry in our heads various mental representations of our body—one example is the wellknown brain map of our sense of touch, sometimes called a homunculus (right). New studies show how such mental maps blur with age and readily extend to accommodate bionic limbs.


Blurred Bodies
As we age, our sense of touch becomes less accurate— some elderly people have a tough time reading Braille, for example. Looking for the roots of this sensory decline, German researchers at Ruhr University Bochum stumbled on a surprise: rather than shriveling up, the brain’s sensory body map—which helps us discriminate Braille letters by determining where the raised bumps are in relation to one another—expands with age, exactly as it does during learning. What could explain this paradox? The homunculus is made up of brain cells that represent our fingers, arms, and so on, loosely tracing a distorted human figurine along the cerebral cortex. In younger people the map stays sharp thanks to cells that dampen neural activity between areas representing different body parts. During aging, however, these cells presumably start to slack off; like an ink drawing that someone spills water on, the contours of the body map start to bleed. Luckily, studies show that a fuzzy old homunculus can be brought back into focus by stimulating the fingertips with a special apparatus, allowing at least some recovery of sensory precision.


Naturally Bionic
To the brain, electronic hardware is no different from flesh and blood, suggests a study at the University of California, Berkeley. In the experiment, monkeys learned to control a computer cursor—a stand-in for a bionic limb—through microelectrodes wiretapping their motor cortex. Although this feat is nothing new, the researchers showed for the first time that a stable memory of the new accessory had formed in the brain. During normal development, a baby learns to control its limbs by creating a mental map of the movable parts of its body—a motor homunculus of sorts. The new finding parallels that process, says neuroscientist Jose Carmena, who led the study, “but it’s about a prosthetic device, and that’s what is profound about it. We’re talking about an extension of your body’s schema.” In other words, once the brain-machine interface gets up to speed, our gray matter might already be set up to achieve effortless, plug-and-play-like control of electronic add-ons. —Frederik Joelving

Source of Information : Scientific American Mind November-December 2009

Does D Make a Difference?

New studies show low vitamin D levels may impair cognitive function

The push to prevent skin cancer may have come with unintended consequences—impaired brain function because of a deficiency of vitamin D. The “sunshine vitamin” is synthesized in our skin when we are exposed to direct sunlight, but sunblock impedes this process. And although vitamin D is well known for promoting bone health and regulating vital calcium levels—hence its addition to milk—it does more than that. Scientists have now linked this fat-soluble nutrient’s hormonelike activity to a number of functions throughout the body, including the workings of the brain. “We know there are receptors for vitamin D throughout the central nervous system and in the hippocampus,” said Robert J. Przybelski, a doctor and research scientist at the University of Wisconsin School of Medicine and Public Health. “We also know vitamin D activates and deactivates enzymes in the brain and the cerebrospinal fluid that are involved in neurotransmitter synthesis and nerve growth.” In addition, animal and laboratory studies suggest vitamin D protects neurons and reduces inflammation. Two new European studies looking at vitamin D and cognitive function have taken us one step further. The first study, led by neuroscientist David Llewellyn of the University of Cambridge, assessed vitamin D levels in more than 1,700 men and women from England, aged 65 or older. Subjects were divided into four groups based on vitamin D blood levels: severely deficient, deficient, insufficient (borderline) and optimum, then tested for cognitive function. The scientists found that the lower the subjects’ vitamin D levels, the more negatively impacted was their performance on a battery of mental tests. Compared with people with optimum vitamin D levels, those in the lowest quartile were more than twice as likely to be cognitively impaired.

A second study, led by scientists at the University of Manchester in England and published online this past May, looked at vitamin D levels and cognitive performance in more than 3,100 men aged 40 to 79 in eight different countries across Europe. The data show that those people with lower vitamin D levels exhibited slower information processing speed. This correlation was particularly strong among men older than 60 years. “The fact that this relationship was established in a largescale, clinical human study is very important,” Przybelski says, “but there’s still a lot we don’t know.” Although we now know that low levels of vitamin D are associated with cognitive impairment, we do not know if high or optimum levels will lessen cognitive losses. It is also unclear if giving vitamin D to those who lack it will help them regain some of these high-level functions. Because cognitive impairment is often a precursor for dementia and Alzheimer’s disease, vitamin D is a hot topic among Alzheimer’s scientists, who are racing to answer these questions. Przybelski, for example, is planning a study of vitamin D supplements in healthy, normal elderly adults living in an assisted-living community to see if it will affect their incidence of Alzheimer’s in the long term. So how much is enough vitamin D? Experts say 1,000 to 2,000 IU daily—about the amount your body will synthesize from 15 to 30 minutes of sun exposure two to three times a week—is the ideal range for almost all healthy adults. Keep in mind, however, that skin color, where you live and how much skin you have exposed all affect how much vitamin D you can produce. —Diane Welland

Source of Information : Scientific American Mind November-December 2009

Personal Training by Phone

Encouraging physical activity may be as simple as offering small rewards

The promise of a gold star can get grade school students to read more and even take on extra-credit projects. But encouraging positive behavior in adults is more complex, right? Not necessarily, according to recent studies of a mobile phone application called UbiFit. The program, designed by researchers at Intel Research Seattle and the University of Washington, taps into the psychology of motivation by offering seemingly insignificant rewards—graphics of flowers—that people end up striving to attain. UbiFit gathers information from a small, wearable accelerometer to chart an individual’s daily physical activity, tracking various kinds of motion with little input or logging required. Depending on the user’s activity level, flowers of different sizes and colors begin to appear on his or her phone’s background display. In a study conducted this past winter, participants with this “garden” feature from UbiFit had more success maintaining their fitness regimens over the holidays than those whose software simply tracked activity without offering rewards.

Lead researcher Sunny Consolvo, a computer scientist at Intel, read up on classic psychology theories before starting the project. Consolvo suspected that presenting the data in a simple and subtle way would be effective, but even she was surprised by how much the garden graphic seemed to motivate people. “It even worked on me,” she recounts. UbiFit is not yet available for purchase, but other devices exist that similarly use rewards and encouragement to tap into the psychology of motivation [see the review “Boost Your Motivation,” by Melinda Wenner, on page 72]. —Erica Westly

Source of Information : Scientific American Mind November-December 2009

Risk-Taking Teens Have More Mature Brains

New research finds adultlike structure in the brains of wayward youths

We often hear that teens are irresponsible because their brains are immature. But, contradicting that idea, teen turmoil is completely absent in more than 100 cultures around the world [see “The Myth of the Teen Brain,” by Robert Epstein; Scientific American Mind, April/May 2007]. Nevertheless, neuroscience studies do indeed suggest that the gray matter in the frontal cortex of teens, as compared with adults, is not fully developed. Now a study by neuroscientist Gregory S. Berns and his colleagues at Emory University adds a new wrinkle to the gray matter findings, reporting that teens who are risk takers and drug users actually appear to have a more developed brain than their conservative peers.

The Berns team assessed the risk-taking tendencies of 91 teens between the ages of 12 and 18 with a written test and a drug test. Then, using a relatively new MRI technology called diffusion tensor imaging, the researchers looked at the amount of white matter in the frontal cortex of the teens’ brains. White matter contains the protein myelin, which coats neurons’ spindly axons as they reach toward other areas of the brain. Myelin is important for efficient signaling between neurons, and it is known to grow considerably between childhood and adulthood.

The investigators found that engaging in dangerous behaviors was associated with increased white matter, a result directly opposite to the gray matter findings. One possible interpretation: people whose brains mature early might be more prone to engage in adult activities. But Berns suggests that the entire teen brain idea might be overhyped.
“Nobody denies that the brain develops or that teens take risks,” he says, “but how the two observations got intertwined is beyond me.” Developmental psychologist Laurence Steinberg of Temple University questions the significance of the new study. Other researchers have found a connection between increased white matter and reduced impulsivity, Steinberg explains, which could mean a reduced likelihood of risk taking—the opposite of the Berns finding. Renowned neuroscientist Michael S. Gazzaniga of the University of California, Santa Barbara, is more impressed. “So much for the much touted model of the teenage brain,” Gazzaniga says. “Back to the drawing boards again.” —Robert Epstein


Source of Information : Scientific American Mind November-December 2009

Pollution’s Toll on the Brain

Breathing dirty air may have serious effects on cognition, in children and adults

In these days of hybrid cars and carbon credits, it is common knowledge that substances exhaled by autos and coal plants are harmful to our respiratory system. What may be surprising is the degree to which they may harm the brain—in some instances, as much as exposure to lead. A recent string of studies from all over the world suggests that common air pollutants such as black carbon, particulate matter and ozone can negatively affect vocabulary, reaction times and even overall intelligence.

The most recent of these studies found that New York City five-year-olds who were exposed to higher levels of urban air pollutants known as polycyclic aromatic hydrocarbons (PAH) while in the womb exhibited an IQ four points lower than those subjected to less PAH. Alarmingly, “the drop was similar to that seen in exposure to low levels of lead,” says epidemiologist Frederica Perera, director of the Columbia Center for Children’s Environmental Health and head author of the study, in which mothers wore personal air monitors during their pregnancy.

The IQ change was enough of a dip to affect school performance and scores on standardized tests. “These weren’t even superimpressively high levels of pollution,” Perera says. “The levels we measured in our study are comparable to those in other urban areas.” Most PAH pollutants come from motor vehicle emissions, especially diesel- and gas-powered cars and trucks, and from the burning of coal. (Tobacco smoke is another source, so the researchers did not enroll smokers in the study and corrected for secondhand smoke exposure.)

But children’s growing brains are not the only ones affected by this dirty air. A 2008 study in 20- to 50-yearolds conducted jointly by the schools of public health at Harvard University and the University of North Carolina at Chapel Hill pinpointed ozone-related reductions in attention, short-term memory and reaction times equivalent to up to 3.5 to five years of age-related decline. What’s to be done about these brain-harming pollutants? “It’s not a mystery how to reduce them—we need better policies on traffic congestion and technologies for alternative energy and energy efficiency,” Perera says. Fortunately, thereare also more immediate ways to reduce your exposure to the toxic chemicals, such as limiting outdoor physical activity on smoggy days. Ozone alerts and air-quality reports have become a routine part of the morning weather forecast and also appear on sites such as weather.com. “Depending on where you live, it becomes a good idea to pay attention to air quality before exercising outdoors,” says Lisa Jackson, administrator of the U.S. Environmental Protection Agency. “There is also some benefit to dialing down the intensity if you can’t avoid exercising outside—for example, walking instead of running.” Another smart move: avoid walking, running or bike riding on major streets with heavy bus, truck or car traffic whenever possible, Jackson says. Until emissions controls and other EPA policies begin to significantly impact the levels of traffic-related pollutants in the air around us, bathing our brains in as little of the stuff as possible may be our—and our children’s—best bet. —Sunny Sea Gold


Source of Information : Scientific American Mind November-December 2009

Why Success Breeds Success

The brain may not learn from its mistakes after all

Have you ever bowled a string of strikes that seems like it came out of nowhere? There might be more to such streaks than pure luck, according to a study that offers new clues as to how the brain learns from positive and negative experiences. Training monkeys on a two-choice visual task, researchers found that the animals’ brains kept track of recent successes and failures. A correct answer had impressive effects: it improved neural processing and sent the monkeys’ performance soaring in the next trial. But if a monkey made a mistake in one trial, even after mastering the task, it performed around chance level in the next trial— in other words, it was thrown off by mistakes instead of learning from them. “Success has a much greater influence on the brain than failure,” says Massachusetts Institute of Technology neuroscientist Earl Miller, who led the research. He believes the findings apply to many aspects of daily life in which failures are left unpunished but achievements are rewarded in one way or another—such as when your teammates cheer your strikes at the bowling lane. The pleasurable feeling that comes with the successes is brought about by a surge in the neurotransmitter dopamine. By telling brain cells when they have struck gold, the chemical apparently signals them to keep doing whatever they did that led to success. As for failures, Miller says, we might do well to pay more attention to them, consciously encouraging our brain to learn a little more from failure than it would by default.

Source of Information : Scientific American Mind November-December 2009

Related Disorders

Insomnia and depression may arise from common genes

Sleepless nights may be genetically linked to depression, according to new research from the University of Pennsylvania and Virginia Commonwealth University. In a study of twins, researchers found that genetically identical twins who suffered from insomnia were significantly more likely than nonidentical twins to also suffer from depression. The two disorders have been linked before, but the role of genetics has not been clear. The new study indicates that insomnia and depression have overlapping genes, and the next step is to pinpoint those genes through DNA analysis. Possible contenders are the genes related to the neurotransmitters serotonin and norepinephrine, which are involved in both the sleep-wake cycle and mood regulation.

Source of Information : Scientific American Mind November-December 2009

Reading Minds

Advanced language skills may be essential to predicting others’ thoughts


What’s this guy thinking? Does he know what I know? Most of us develop the ability to make inferences about what other people might be thinking, the hallmark of “theory of mind,” at age four. Scientists have long known that the acquisition of language plays a role in this process, but so far it had been unclear whether social experience could substitute for it. A new study suggests it cannot. Jennie Pyers of Wellesley College and her colleagues studied deaf adults in Nicaragua. Some of the participants had learned an early, rudimentary form of Nicaraguan sign language (NSL), whereas others were fluent in a more sophisticated form of NSL that included mental state terms, such as “know” and “think.” Pyers and her team had all signers undergo a socalled false-belief test in which signers looked at a sequence of pictures showing two boys playing in a room and storing a toy underneath a bed. After one of the boys leaves the room, the other moves the toy to a different location. Study participants then had to choose between two pictures to complete the series: the first showed the returning boy looking for the toy in its original location on reentering the room, and the second showed him looking in its new location. Those Nicaraguans with complex sign language skills were more likely to choose the first picture—indicating an understanding of false belief—than were those with less developed language skills. Moreover, after a two-year period during which early signers improved their NSL knowledge, they performed better at the false-belief task. The findings support the hypothesis that although an implicit understanding of other people’s knowledge and belief states develops early in life, advanced language is needed “to unlock the ability to productively use it,” Pyers says.

Source of Information : Scientific American Mind November-December 2009

Mental Bottleneck

Our ability to multitask is limited by the prefrontal cortex

Next to the many amazing feats our brain pulls off daily, its inferior ability to juggle a few simple tasks sticks out like a sore thumb. Now research from Vanderbilt University suggests that these limits on multitasking arise from slow processing in the prefrontal cortex, the brain’s central executive. Although the area has been known to be involved in multitasking, its exact role is a matter of debate. Using functional MRI, the researchers found that when people were juggling two assignments, their prefrontal cortex appeared to deal with the tasks one by one—creating that familiar mental bottleneck—instead of processing them in parallel as do sensory and motor parts of the brain. With training the prefrontal activation time became shorter, cranking up the speed of the mental conveyor belt by about 10 times. Unfortunately, the researchers note, the benefits of training might not apply to tasks other than those specifically practiced. “It’s not like you become able to multitask [with drills]; it’s just that you become able to do each task very quickly,” says cognitive neuroscientist Paul Dux, now at the University of Queensland in Australia, who conducted the experiment.

Source of Information : Scientific American Mind November-December 2009

Wide-Reaching Effects

The brain’s plasticity is even greater than suspected

The idea that the adult brain changes with experience was once a radical idea, but it is now well accepted that certain areas—say, the motor cortex, when learning a new physical skill—can grow new neurons or create stronger connections.

Now scientists report that the brain is even more mutable than suspected. Thanks to an unconventional research technique, neuroscientists have found the first physical proof that new experiences and information have wide-ranging effects throughout both hemispheres of the brain, rather than just creating connections in one discrete area.

The story begins in the hippocampus, the area of the brain associated with shortterm memory. In the past, researchers have electrically stimulated slices of disembodied hippocampus and seen how stimulation changes the structure of nearby neurons. But the new study took a different tack. Led by Santiago Canals, a biological cyberneticist currently at the Institute of Neurosciences in Alicante, Spain, the team set aside the dissected hippocampi in favor of a more true-tolife approach. After implanting electrodes in live rats, the group used a combination of functional MRI, electroencephalography (EEG) and microstimulation— triggering nerve cells with small doses of electric current—to trace in real time what happened to neuronal structures in the rats’ brains when neurons in the hippocampus were stimulated. In contrast to studying the slices, this method allowed the scientists to see what happened in the hippocampus in context with what was going on all over the brain—like comparing a 2-D drawing of a bedroom with a 3-D rendering of the whole house.

“We have learned that what we call neuronal plasticity isn’t exclusive to individual synapses or even the neurons where they contact but rather occurs throughout the functional network in which synapses and neurons are embedded,” Canals says. “Those networks are absent in brain slices, so they couldn’t be studied before.”

By showing how activity in the hippocampus causes widespread changes in brain structure, Canals says the findings could explain why new memories are at first dependent on the hippocampus but can eventually be recalled without triggering that part of the brain at all.

Source of Information : Scientific American Mind November-December 2009