Sunday, October 10, 2010

Brain Science in the News

This is another in my occasional link dumps - clearing out some old tabs. Most of these come from Big Think, one of the coolest newer sites on the web - check them out if you haven't already.

Speak, Memory: Language and the Brain


In the field of neuroscience, we know far less about language than about other brain mechanisms like emotion, memory, or sensation. The inherent difficulty of studying language is that it is so closely linked to thought. There are certainly parts of the brain in which language is concentrated, but it is hard to differentiate these areas from those involved in non-language cognitive processes. Language areas also appear to be quite fluid, occupying different parts of the brain among different individuals. And because language is a strictly human phenomenon, researchers can't use animal studies to investigate brains at the neuron level.

Paradoxically, language-specific areas were the first localized areas to be discovered in the brain. As discussed earlier in our Going Mental series, French physician Paul Broca and German neurologist Carl Wernicke independently discovered two important language areas in the 1860s. Based on their brain damage studies, a cohesive picture of language processing emerged: stimuli from the auditory cortex (speech) or the visual cortex (reading) travel to Wernicke's area in the left posterior temporal lobe, where it is processed and comprehended. From there, a bundle of nerves called the arcuate fasiculus connects to Broca's area in the frontal lobe, which is responsible for language production. From there, the message is sent to the motor cortex for translation either into speech or writing. This succinct language circuit was the prevailing model for over a century; the only problem is that new tests show it to be inaccurate.

Read the whole post.

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Braingasm: Sex and Your Synapses


It is a cliché that the brain is the "largest sex organ," but the repetition of the phrase doesn't make it any less true. The mechanics of its role during sex are less obvious and less well understood than that of the body's other sex organs, but by using brain imaging scans, neuroscientists have begun to get a sense of what parts of the brain light up during sex, especially at the moment of orgasm.

In his Big Think interview, Rutgers psychologist Barry Komisaruk, a pioneer of neuroscientific sex studies on the female orgasm, told us what science now knows about "la petite mort." One early study of orgasms, he explains, suggests that the subjective experience of orgasm is very similar between men and women. Despite having different anatomies, men and women seem to be hard-wired to experience sexual pleasure in the same way. But does this translate to a similarity in the brain?

Read the whole post.

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How the Brain Fears


Emotions are messy, complicated phenomena—not just for lovers, but for neuroscientists as well, because they combine cognition with physiology. Scientists once thought of emotion as a purely mental activity which elicited bodily responses, but they now see the mind and body as equally responsible for creating the experiences of fear, joy, and anger. Despite this complexity, science is beginning to understand emotion by examining one emotional pathway at a time, with the hope of some day combining them into a comprehensive understanding.

Fear is the most researched and best understood of all emotions. It's the easiest emotion to study because it has the most measurable physiological response, but it's also the most important emotion we have from an evolutionary standpoint. Learning to fear something dangerous that caused pain in the past, like a snake or a spider, most likely helped our ancestors to survive. And proving its evolutionary importance, the fear circuit in our brains is actually a shortcut that allows dangerous stimuli to bypass parts of the brain normally involved in sensory processing, as NYU neuroscientist Joseph LeDoux explains in the video below.

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The Neuroscience of Cocktail Party Conversation


So you're at a cocktail party, and, like at most cocktail parties, there are a handful of conversations happening around the room. Yet, despite the dull roar of laughter and discussion, you have no trouble focusing on the voice of the person with whom you're speaking. You see her eyes and lips moving and you understand every word she is saying. But as often happens, you begin to lose interest in the conversation. And though you continue to nod your head and say things like, "Uh-huh, Oh really?" you consciously turn your attention to the uproarious banter of a more enticing conversation happening elsewhere in the room.

How is it that in a blink of an eye, we're able to selectively refocus our auditory attention to a distant conversation, while ignoring the conversation that's happening right in front of us? The answer, it turns out, is a mystery

According to Tony Zador, a Professor of Biology and Program Chair of Neuroscience at the Cold Spring Harbor Laboratory, the brain mechanisms responsible for any kind of attention, whether visual or auditory, are probably not fundamentally different. However, the challenge of understanding how the brain goes about selectively listening to one cocktail party conversation over another is twofold. The first issue is one of computation: "We have a whole bunch of different sounds and from a bunch of different sources and they are superimposed at the level of the ears and somehow they’re added together and to us it’s typically pretty effortless to separate out those different threads of the conversation, but actually that’s a surprisingly difficult task," says Zador. Scientists were able to program computers to recognize speech in controlled situations and quiet rooms as far back as ten years ago, says Zador, but when deployed in real world settings with background noise their algorithms fail completely. Humans on the other hand have evolved to effortlessly break down the components of an auditory scene.

Read the whole post.

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The narrative of personal improvement is as American as baseball—almost as American as a fondness for illegal and prescription drugs. From steroids and human growth hormones on the baseball diamond to amphetamines in college libraries and quadrangles, performance enhancing drugs combine a desire for productivity and success with drug abuse in a way that is uniquely American. And the statistics confirm their growing demand: the journal Addiction reports that on certain college campuses, especially competitive Northeastern colleges, up to 25 percent of students admitted to having misused ADHD medication in the past year. Yet despite their prevalence, these drugs, and the disorder they treat, are highly misunderstood.

Firstly, the widespread abuse contributes to a sense that ADHD is an invented illness. This is simply not the case says Dr. Harold Koplewicz, one of the nation's leading child psychiatrists. Attention Deficit/Hyperactivity Disorder may be misunderstood, he says, but that doesn't make it any less real: It is a neurological disorder that affects an estimated 15 to 20 million Americans and is marked by measurable neurochemical differences in the brain.

"When you have Attention Deficit/Hyperactivity Disorder, you use your dopamine and your norepinephrine faster in your brain than the average person," says Koplewicz. "And when you don’t have enough of that, you become inattentive or you become more impulsive or you’re more hyperactive."

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By News Staff | October 2nd 2010

Like many of history's greatest minds, narcissists spend a great deal of time deep in thought - but for narcissists it is thought about themselves.

Neuroscientists recently found a correlation between high scores on the Machiavellian Egocentricity subscale - a measure of narcissism - and activity during rest in the posteromedial cortex, a brain region that previous studies have associated with thoughts about the self. The study also found a correlation between poor decision-making and brain activity during rest in the medial prefrontal cortex. Impulsive action without regard for consequences is another aspect of psychopathic behavior.

Narcissists thinking about themselves all of the time is more than a stereotype. Since narcissism is one component of the psychopathic mind, differences between the brain patterns of normal people and narcissists may help psychiatrists to understand and treat dangerous individuals.

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