Monday 12 December 2011

Nine Stubborn Brain Myths That Just Won’t Die, Debunked by Science

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By Adam Dachis Dec 12, 2011 8:00 AM

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Nine Stubborn Brain Myths That Just Won’t Die, Debunked by Science

Brain games will make you smarter! The internet is making you dumber! Alcohol is killing your brain cells! The brain is a mystery we've been trying to solve for ages, and the desire to unlock its secrets has led to vast amounts of misinformation. Many of these false notions are more widely believed than the truth. We took our healthy skepticism and a bunch of brain research to find the truth behind some of the most common myths about intelligence and our brains. Here's what we learned.
Photo by Igor Nazarenko (Shutterstock).

Myth 1: Left-Brained People Are Organized, Right-Brained People Are Creative

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We're a stubborn people who become set in our ways, so it's no wonder we want to believe that our inclination towards creativity or organized thinking is decided at birth. The right- or left-brained myth suggests we're simply fulfilling a version of our genetic destiny and we should accept our strengths and weaknesses as part of who we are. But as Lisa Collier Cool points out in her article for Yahoo Health, we're not really right- or left-brained at all:

This myth began in the 1800s, where doctors discovered that injury to one side of the brain frequently caused loss of specific abilities. Brain scan experiments, however, show that the two halves of the brain are much more intricately linked than was originally thought, so problem-solving or creative tasks fire up activity in regions of both hemispheres of the brain, not just half. It is true that the right side of the brain controls the left side of the body and vice versa, so a right-brain injury can cause disability on the left side of the body.

More recently this myth has been used as an attempt to explain creativity, dyslexia, and even homosexuality in left-handed people, but the origin of the southpaw is still a mystery. Whether or not there is a compelling link between right- or left-handedness and specific common traits remains to be seen, but rest-assured that being more creative or more organized doesn't inhibit you from having a talent for both.

Myth 2: Your Memory Is An Exact Account of What You See and Experience

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Some of us have better memories than others, but no memory is perfect. If you need proof, close your eyes and try to imagine the face of someone you know. In fact, try to imagine your own face. While you'll be able to conjure up a decent idea of the way you or anyone else looks, you won't be able to envision every last detail. This is because our memories don't recall anything we see, hear, sell, taste, or touch with much detail at all. Instead, as psychologist Dan Gilbert points out in his book Stumbling On Happiness, our brains record the seemingly necessary details and fill in the rest when it's time to remember:

[T]he elaborate tapestry of our experience is not stored in memory-at least not in its entirety. Rather, it is compressed for storage by ﬁrst being reduced to a few critical threads, such as a summary phrase ("Dinner was disappointing") or a small set of key features (tough steak, corked wine, snotty waiter). Later, when we want to remember our experience, our brains quickly reweave the tapestry by fabricating-not by actually retrieving-the bulk of the information that we experience as a memory. This fabrication happens so quickly and effortlessly that we have the illusion (as a good magician's audience always does) that the entire thing was in our heads the entire time.

Gilbert's conclusions come from memory researcher Daniel Schacter, who believes the construction of memory is very similar to the way we imagine the future:

We have argued in recently that memory plays a critical role in allowing individuals to imagine or simulate events that might occur in their personal futures. We have further suggested that understanding memory's role in future event simulation may be important for understanding the constructive nature of memory, because the former requires a system that allows flexible recombination of elements of past experience, which may also contribute to memory errors.

While a little common sense and life experience can demonstrate the imperfections in your (and everyone else's) memory, Schacter's research points to two important things: we're no good at recalling past events or imagining the future because our process for doing either is essentially the same—at least as far as our brain functionality is concerned. While this points to much more of a problem than a solution, it certainly helps to remember that no memory is perfect and we're all designed to recall with error. Next time someone gets something wrong, it's at least worth remembering that.

Myth 3: You Only Use 10% of Your Brain

As with many myths, you can generally begin the debunking process by reminding yourself that the claim is pretty ridiculous. If we only used 10% of our brains, what's the point of the other 90%? According to myth-busting site Snopes, it was television that made us dumber:

In 1998, national magazine ads for U.S. Satellite Broadcasting showed a drawing of a brain. Under it was the caption, "You only use 11 percent of its potential." Well, they're a little closer than the ten-percent figure, but still off by about 89 percent. In July 1998, ABC television ran promotional spots for The Secret Lives of Men, one of their offerings for the fall season's lineup. The spot featured a full-screen blurb that read, "Men only use ten percent of their brains."

After that, champions of the paranormal used the 10% claim to explain the potential for psychic powers. It became fun to imagine the incredible potential available to us humans once we were able to unlock the remaining 90%. Unfortunately for superpower fans everywhere, we're already enjoying most of what our brains can currently offer. Lisa Collier Cool explains:

Brain imaging studies using PET scans and functional MRI show that any mentally complex activity uses many areas of the brain, and over a day, just about all of the brain gets a workout. More proof that the entire brain is crucial for daily life is the devastating impact of damage to even a small area of the brain. However, we do have some brain reserves. An autopsy study found that seniors who stay mentally active-through activities like reading the paper, going to the theater, or playing chess-are less likely to develop Alzheimer's disease-even if they have the characteristic physical brain changes typical of dementia, suggesting that mental function has a "use it or lose it" component. That allows people who keep their brain stimulated to develop more brain reserves, allowing them to continue functioning normally even as their brains are being damaged by Alzheimer's.

While you can't look forward to developing incredible superpowers with the help of rapid evolution, or any other crazy theory, you can keep yourself healthier later in life by simply staying mentally active. You may not be able to bend metal with your mind, but at least you'll stay coherent in your golden years.

Myth 4: Alcohol Kills Brain Cells

Just as we noted when debunking the myth that you only use 10% of your brain, a little bit of brain damage goes a long way. If you were actively killing brain cells when consuming alcohol, you'd notice some permanent side effects pretty quickly. Although alcohol does have a significant effect on your brain and body, brain damage isn't a given. You'll have to drink yourself into a coma to go that far.
The proof comes from a 1993 study by Grethe Jensen that matched brain samples from both (deceased) alcoholics and non-alcoholics and found no difference in the density of brain cells. (You can read more about this study here.) What alcohol actually does in inhibit the functionality of brain cells, and former Lifehacker writer Kevin Purdy explained it best:

What alcohol can and does do to your brain is affect the way your neurons get their firing triggers from glutamate. It infiltrates the glutamate receptors in your synapses, hurting their ability to send off their normal "fire" messages. Alcohol has this impact all across your brain—the parts that control muscles, speech, coordination, judgment, and so on. Keep that in mind the next time you or someone else claims that they drive, golf, or otherwise perform some task better with alcohol's help.

In the end, you just need to worry more about your choices than the lifespan of your brain.

Myth 5: The Internet Is Making Us Dumber

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If you're familiar with the term "sweeping generalizations," this myth is one of them. Any claim that takes on a large entity and attempts to boil it down to a single, simplistic conclusions is bound to be wrong. This is how we end up with stereotypes. Claiming that the internet is making us dumber could have the glimmer of truth under specific circumstances, but so far no research points to any significant dumbing down of the sort. The reason we find it easy to believe the internet is making us dumber is because, in some ways, it's making us less self-reliant. Our GPS devices navigate for us and we neglect to remember things because we have Google search. That doesn't make us dumber, necessarily, but rather causes us to rely more on what psychologist Daniel Wagner calls transactive memory. This type of memory is actually very useful because it allows us to, in essence, store more data in less space. Instead of remembering the contents of an entire article, we can simple remember the name or a few key words that we can entire into a search engine to pull it up.
This comes with the obvious downside of lacking the full recall for actual information in your brain, which is why many people feel the internet is turning us into idiots. When our access is cut off, suddenly we're bereft of our knowledge because our transactive memories are rendered useless. The reality is, without actual proof that the internet is making us dumber, so far it appears that the entire idea hinges on the evolving manner in which we interact with and access information as opposed to any sort of fact, making this more of a cultural claim than a scientific one.

Myth 6: Listening to Classical Music Turns Babies into Geniuses

This myth began with a study conducted by Dr. Gordon Shaw and Dr. Frances Rauscher at UC Irvine in the early 90s. Preliminary results suggested that a specific piece of music composed by Wolfgang Amadeus Mozart boosted the spatial-temporal reasoning skills in young children. This made for big headlines and the creation of entire businesses surrounding the sale of Mozart-based products to mothers who wanted their children to become geniuses with the press of a play button. According to Brian Dunning of the podcast Skeptoid, the final results weren't quite so miraculous. He said, "although they had some promising preliminary results from a particular Mozart piece which made immediate worldwide headlines, the full study eventually showed no significant result." Likewise, in an in depth analysis on the Mozart Effect, Donna Lerch and Thomas Anderson concluded:

The music of Wolfgang Amadeus Mozart is both physically and aesthetically accessible to the general public. A number of studies have indicated that listening to Mozart's work may temporarily increase cognitive skills. Other studies have found no statistically significant "Mozart effect". It is unfortunate that the media and commercial ventures have taken the initial modest, unverified study and conjured up a pseudo-science which gave rise to, and which continues to promote, a full-blown industry.

Despite the readily available truth, the preliminary findings of this initial study were blown so far out of proportion that Mozart brain boost is one of the more stubborn myths still alive in our culture. If you like classical music, there's likely no harm in playing it for your child so long as you don't expect it to do any of the hard work for you.

Myth 7: Brain Games Make You Smarter

Wouldn't it be nice if we could actually boost our brain power by playing a few games on the bus ride to work? That's the promise the popular Nintendo DS title Brain Age made, starting a brain games trend that rages on. The BBC commissioned a commissioned a study to test these claims and found that they didn't really make a difference:

More than 8,600 people aged 18 to 60 were asked to play online brain games designed by the researchers to improve their memory, reasoning and other skills for at least 10 minutes a day, three times a week. They were compared to more than 2,700 people who didn't play any brain games, but spent a similar amount of time surfing the Internet and answering general knowledge questions. Researchers said the people who did the brain training didn't do any better on the test after six weeks than people who had simply been on the Internet. On some sections of the test, the people who surfed the Net scored higher than those playing the games.

That isn't to say that practicing simple math—one of the games included in Brain Age—won't do you some good. We use simple math on a daily basis, after all. That said, look at any brain games you play as specific practice. You'll get better at that game, but don't expect any boost in your general intelligence.

Myth 8: Your IQ Is Fixed and Stays the Same Throughout Your Life

Your IQ, or intelligence quotient, is a score that's supposed to quantify your level of intelligence. What defines intelligence is still up for debate, so a high IQ isn't necessarily an accurate measurement, but it has long been assumed that our scores don't change—we're stuck at the level of intelligence we were born with. As you may have guessed, that's not true. Business Insider points to a few studies that show changes in IQ after just a few weeks of effort:

There's a lot of research supporting this theory. In one, "33 British students were given IQ tests and brain scans at ages 12 to 16 and again about four years later by researchers at the Wellcome Trust Centre for Neuroimaging at University College London; 9% of the students showed a significant change of 15 points or more in IQ scores," reports the Journal. And these changes weren't just due to measuring errors. The MRIs showed changes in gray matter - which are linked to IQ - says one of the study's co-authors, Cathy Price.

This is good news, because it seems that having a higher IQ is a good thing. People with a lower IQ (meaning in the 75 to 90 range) are more likely to wind up in prison, in poverty, or drop out of high school. A study conducted at the University of Delaware asserts that a higher IQ also has a correlation with higher social intelligence. Since IQ can change, these studies may not relate so much to people with higher scores but rather hardworking, studious individuals. Either way, there seems to be no harm in boosting your score and nothing barring you from doing so.

Myth 9: Your Brain Works Better Under Pressure

At some point in your life, you may have experienced a moment where you had an impossible deadline and somehow managed to finish your work—perhaps even exceptionally well. When the pressure is on, sometimes we find it in ourselves to pull through. Although a ticking clock can be an excellent motivator, as the looming consequences of missing a deadline can certainly get you working fast, it doesn't result in better brain performance. In fact, according to the Franklin Institute, pretty much any kind of stress makes it harder for your brain to function:

As science gains greater insight into the consequences of stress on the brain, the picture that emerges is not a pretty one. A chronic overreaction to stress overloads the brain with powerful hormones that are intended only for short-term duty in emergency situations. Their cumulative effect damages and kills brain cells.

In the end, if you believe you work better under pressure it's simply because the end result seems to justify that belief. Stress isn't enabling you to work better, but simply providing the motivation to get you to work in the first place. You'll be doing yourself a favor if you find a better way to get your work done before the clock starts ticking, but if you get stuck in a pinch at least there are a number of ways to keep the stress you're feeling to a minimum.

Thursday 8 December 2011

Maternal care influences brain chemistry into adulthood, animal study shows

In a study on mice, scientists have discovered that the effect of the peptide hormone of NPY depends on how much care and attention the young animals experienced in the first three weeks of life. Mice who had received little care from their mothers were more anxious adults than their counterparts who had received intensive attention in their early weeks of life. (Credit: Copyright Max-Planck-Gesellschaft)

Maternal Care Influences Brain Chemistry Into Adulthood, Animal Study Shows

ScienceDaily (Dec. 7, 2011) — The effect of the messenger substance neuropeptide Y depends on the behaviour of the mother during infancy. Neuropeptide Y (NPY) is the most abundant peptide hormone of the central nervous system. It is involved in various processes including stress management, the development of anxiety behaviour and body weight regulation.

A collaborative research group including scientists from the Max Planck Institute for Medical Research in Heidelberg has demonstrated using mice that intensive maternal care during infancy promotes the effect of NPY in the brain. As a result of receiving such care, the animals were also less anxious in adulthood and weighed more than their counterparts who had received less affection. The research group was able to show that the effect is explained by the maternal care which stimulated the persistent formation of certain NPY receptors in the forebrain.

Neuropeptide Y (NPY) assumes several key roles in the brain's complex control circuits. The messenger substance not only influences body weight but also controls, among other things, the development of anxiety and stress responses. Hence NPY plays an important role in a series of mental illnesses such as post-traumatic stress disorders and anxiety disorders. NPY takes effect in the brain by binding to different docking sites on the neurons -- the NPY receptors. In this way, the hormone triggers signal cascades which control the different physical functions.

In a study on mice carried out in Rolf Sprengel from the Max Planck Institute for Medical Research and his colleagues in Italy have shown that the effect of NPY depends on how much care and attention the young animals experienced in the first three weeks of life. Mice who had received little care from their mothers were more anxious adults than their counterparts who had received intensive attention in their early weeks of life. They also remained slimmer throughout their lives. As the researchers discovered, the maternal behaviour influenced the formation of NPY1 receptors in the limbic system -- the area of the brain responsible for the processing of emotions.

"We were able to show that the expression of the NPY1 receptor in the young animals' limbic system is increased by good maternal care," explains Rolf Sprengel. "This ensures their healthy development in the long term." The positive effects of maternal care and attention were evidenced by the fact that the young animals gained weight faster and showed greater courage in behavioural experiments as adults than rodents which had experienced little warmth and security after birth.

For their study, the scientists had newborn mice, in which the NPY1 receptors had been switched off selectively, raised by mothers who differed in their behaviour towards the young animals. One group belonged to a mouse strain that was exemplary in caring for its young. These females spent a lot of time with their offspring, fed them frequently and, in addition to extensive grooming, also provided intensive physical contact. In young animals which grew up under such conditions, new NPY-1 receptors formed in the brain's limbic system. The second group of females were programmed to take far less care of the young. In this case, the number of NPY1 receptors in the young mice did not increase.

The neuroscientists' findings help us to reach a better understanding of how experience in the early life of an organism can affect it in later life. "The results of the study show how maternal care and attention have a sustained impact on the chemistry of the limbic system," says Rolf Sprengel. Maternal behaviour can influence the emotions and physical constitution into adulthood in this way.

Story Source:

The above story is reprinted from materials provided byMax-Planck-Gesellschaft.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

I. Bertocchi, A. Oberto, A. Longo, P. Mele, M. Sabetta, A. Bartolomucci, P. Palanza, R. Sprengel, C. Eva. From the Cover: Regulatory functions of limbic Y1 receptors in body weight and anxiety uncovered by conditional knockout and maternal care. Proceedings of the National Academy of Sciences, 2011; 108 (48): 19395 DOI:10.1073/pnas.1109468108

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Wednesday 7 December 2011

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Psychopathy: A Misunderstood Personality Disorder

ScienceDaily (Dec. 7, 2011) — Psychopathic personalities are some of the most memorable characters portrayed in popular media today. These characters, like Patrick Bateman from American Psycho, Frank Abagnale Jr. from Catch Me If You Can and Alex from A Clockwork Orange, are typically depicted as charming, intriguing, dishonest, guiltless, and in some cases, downright terrifying. But scientific research suggests that psychopathy is a personality disorder that is widely misunderstood.

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"Psychopathy tends to be used as a label for people we do not like, cannot understand, or construe as evil," notes Jennifer Skeem, Professor of Psychology and Social Behavior at the University of California, Irvine. Skeem, Devon Polaschek of Victoria University of Wellington, Christopher Patrick of Florida State University, and Scott Lilienfeld of Emory University are the authors of a new monograph focused on understanding the psychopathic personality that will appear in the December issue of Psychological Science in the Public Interest, a journal of the Association for Psychological Science.

In the course of their research, the authors reviewed many scientific findings that seemed to contradict one another. "Psychopathy has long been assumed to be a single personality disorder. However, there is increasing evidence that it is a confluence of several different personality traits," Skeem says. The authors of the monograph argue that rather than being "one thing" as often assumed, psychopathy appears to be a complex, multifaceted condition marked by blends of personality traits reflecting differing levels of disinhibition, boldness, and meanness. And scientific findings also suggest that a sizable subgroup of juvenile and adult offenders labeled as psychopathic are actually more emotionally disturbed than emotionally detached, showing signs of anxiety and dysphoria.

According to Skeem, these important distinctions have long escaped the attention of psychologists and policy-makers. As a result, she and her co-authors set about to try to dispel some of the myths and assumptions that people often make about psychopathy. Although many people might assume that psychopaths are 'born,' not 'made,' the authors stress that psychopathy is not just a matter of genes -- it appears to have multiple constitutional causes that can be shaped by environmental factors. Many psychologists also assume that psychopathy is inalterable -- once a psychopath, always a psychopath. However, there is currently scant scientific evidence to support this claim. Recent empirical work suggests that youth and adults with high scores on measures of psychopathy can show reduced violent and other criminal behavior after intensive treatment.

Along with challenging the assumption that psychopathy is a monolithic entity, perhaps the other most important myth that the authors hope to dispel is that psychopathy is synonymous with violence. Skeem points out that psychopathic individuals often have no history of violent behaviour or criminal convictions. "Psychopathy cannot be equated with extreme violence or serial killing. In fact, "psychopaths" do not appear different in kind from other people, or inalterably dangerous," she observes. Nor is it clear that psychopathy predicts violence much better than a past history of violent and other criminal behavior -- or general antisocial traits.

Effectively dispelling these myths is important, the authors argue, because accurate policy recommendations hinge on which personality traits -- and which groups of people -- associated with psychopathy one is examining. "Decisions about juvenile and adult offenders that are based on faulty assumptions about violence risk, etiology, and treatment amenability have adverse consequences, both for individual offenders and the public," Skeem says.

In clarifying the personality traits that characterize psychopathy, scientists can contribute to prevention and treatment strategies that improve public health and safety. "In short, research on psychopathy has evolved to a level that it can greatly improve on the current, 'one size fits all' policy approach," concludes Skeem

Sunday 27 November 2011

Capacity-Speed Relationships in Prefrontal Cortex

RESEARCH ARTICLE

Capacity-Speed Relationships in Prefrontal Cortex

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Vivek Prabhakaran¹^,²^,³^*, Bart Rypma⁴, Nandakumar S. Narayanan⁵, Timothy B. Meier², Benjamin P. Austin⁶,Veena A. Nair¹, Lin Naing³, Lisa E. Thomas⁷, John D. E. Gabrieli⁸

1 Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 2 Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 3 School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 4Center for Brain Health, University of Texas-Dallas, Dallas, Texas, United States of America, 5 Department of Neurology, Yale University, New Haven, Connecticut, United States of America, 6 Cardiovascular Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 7 Departments of Emergency Medicine, Brigham & Women's Hospital and Massachusetts General Hospital, Boston, Massachusetts, United States of America, 8 Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America

Abstract Top

Working memory (WM) capacity and WM processing speed are simple cognitive measures that underlie human performance in complex processes such as reasoning and language comprehension. These cognitive measures have shown to be interrelated in behavioral studies, yet the neural mechanism behind this interdependence has not been elucidated. We have carried out two functional MRI studies to separately identify brain regions involved in capacity and speed. Experiment 1, using a block-design WM verbal task, identified increased WM capacity with increased activity in right prefrontal regions, and Experiment 2, using a single-trial WM verbal task, identified increased WM processing speed with increased activity in similar regions. Our results suggest that right prefrontal areas may be a common region interlinking these two cognitive measures. Moreover, an overlap analysis with regions associated with binding or chunking suggest that this strategic memory consolidation process may be the mechanism interlinking WM capacity and WM speed.