Word: amygdala
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...some people to suffer that interference and most not? Why does their internal alarm keep shouting "Lion!" long after they've checked every place a lion could plausibly be? The answer has always been thought to lie principally in a small, almond-shaped structure in the brain called the amygdala--the place where danger is processed and evaluated. It stands to reason that if this risk center is overactive, it would keep on alerting you to peril even after you've attended to the problem...
...turns out, the amygdala is indeed a big player in the pathological process of OCD but only one of several players. Functional magnetic resonance imaging (fMRI) and other scanning technologies have allowed researchers to peer deeper than ever into the OCD-tossed brain. In addition to the amygdala, there are three other anatomical hot spots involved in the disorder: the orbital frontal cortex, the caudate nucleus and the thalamus--the first two seated high in the brain, the third lying deeper within...
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...
...such a strategy is in line with other new theories of addiction. Scientists say extinguishing urges is not a matter of getting the feelings to fade but of helping the addict learn a new form of conditioning, one that allows the brain's cognitive power to shout down the amygdala and other lower regions. "What has to happen for that cue to extinguish is not for the amygdala to become weaker but for the frontal cortex to become stronger," says Vocci...
...Shown faces expressing fear, the healthy brains lit up predictably in the lozenge-shaped amygdala, an emotional center involved in recognizing expressions and tones of voice. But with the patients, the same images caused less activation of the amygdala and more of several other areas including the hippocampus, which encodes and retrieves memories. "Instead of processing a particular face in the context of right now, the brain is basically going back into its filing cabinet and picking out previous experiences, which is not an efficient way for it to work," says Malhi, chair of psychological medicine at the University...