Word: cortexes
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Dates: during 2000-2009
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...involving cognitive skills and less able to adjust to new rules quickly. This suggested that those patients might also be less adept at using analytical areas of the brain while performing decision-making tasks. Sure enough, brain scans showed that there were reduced levels of activation in the prefrontal cortex, where rational thought can override impulsive behavior. It's impossible to say if the drugs might have damaged these abilities in the relapsers--an effect rather than a cause of the chemical abuse--but the fact that the cognitive deficit existed in only some of the meth users suggests that...
...contemplates the consequences of actions. Recall the last time you found yourself in a stressful situation--when you were scared, nervous or threatened. Your brain tuned out everything besides whatever it was that was frightening you--the familiar fight-or-flight mode. "The part of the prefrontal cortex that is involved in deliberative cognition is shut down by stress," says Vocci. "It's supposed to be, but it's even more inhibited in substance abusers." A less responsive prefrontal cortex sets up addicts to be more impulsive as well...
...just about how long it takes for the brain to reset itself and shake off the immediate influence of a drug. Researchers at Yale University have documented what they call the sleeper effect--a gradual re-engaging of proper decision making and analytical functions in the brain's prefrontal cortex--after an addict has abstained for at least 90 days...
This work has led to research on cognitive enhancers, or compounds that may amplify connections in the prefrontal cortex to speed up the natural reversal. Such enhancement would give the higher regions of the brain a fighting chance against the amygdala, a more basal region that plays a role in priming the dopamine-reward system when certain cues suggest imminent pleasure--anything from the sight of white powder that looks like cocaine to spending time with friends you used to drink with. It's that conditioned reflex--identical to the one that caused Ivan Pavlov's famed dog to salivate...
...perhaps the most striking difference was in an area in the left prefrontal cortex--the site of activity that marks happiness. While the monks were generating feelings of compassion, activity in the left prefrontal swamped activity in the right prefrontal (associated with negative moods) to a degree never before seen from purely mental activity. By contrast, the undergraduate controls showed no such differences between the left and right prefrontal cortex. This suggests, says Davidson, that the positive state is a skill that can be trained...