Thursday, 25 October 2007

Always Look On The Bright Side of Life

From Science Daily :
A neural network that may generate the human tendency to be optimistic has been identified by researchers at New York University. As humans, we expect to live longer and be more successful than average, and we underestimate our likelihood of getting a divorce or having cancer. The results, reported in Nature, link the optimism bias to the same brain regions that show irregularities in depression.

The study was conducted by a team of researchers from the laboratory of NYU Professor Elizabeth Phelps. The lead author is Tali Sharot, now a post-doctoral fellow at University College London.

The NYU researchers used functional magnetic resonance imaging (fMRI) to examine brain function while participants thought of possible future life events (such as "winning an award" or "the end of a romantic relationship").

"When participants imagined positive future events relative to negative ones, enhanced activation was detected in the rostral anterior cingulate and amygdala, which are the same brain areas that seem to malfunction in depression," said Sharot. "Activation of the rostral anterior cingulate was correlated with trait optimism, with more optimistic participants showing greater activity in this region when imagining future positive events."
...
The brain imaging findings offer a possible mechanism mediating the behaviorally observed optimism bias. The rostral anterior cingulate has previously been shown to be involved in the regulation of emotional responses. The current results suggest that in healthy individuals this region may help integrate and regulate emotional and autobiographical information to generate a positive view of the future.
fMRI strikes again. As predicted in previous posts, this technique is turning out to be a powerful new tool in aiding our understanding of how we think. Or how we think we think.

And from Reuters:
A few nights without sleep can not only make people tired and emotional, but may actually put the brain into a primitive "fight or flight" state, researchers said on Wednesday.

Brain images of otherwise healthy men and women showed two full days without sleep seemed to rewire their brains, re-directing activity from the calming and rational prefrontal cortex to the "fear center" -- the amygdala.

"It's almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses," said Matthew Walker of the University of California Berkeley, who led the study.
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Walker and colleagues at Harvard Medical School used functional magnetic resonance imaging, which can scan brain activity in real time, to see what was going on in the brains of their 26 young adult volunteers.
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"We found a strong overreaction from the emotional centers of the brain," Walker said. "It was almost as if the brain had been rewired, and connected to the fright, flight or fight area in the brain stem."
More, Please

1 comment:

Hildy said...

I'd be interested to know what the effects of sleep deprivation are on eg. soldiers. Especially combined with caffeine and other stimulants commonly used to stay awake for longer periods. A surfacing of more "primitive" instincts doesn't sound like a good idea...