脑部扫描可能揭示风险偏好

This is Scientific American - 60-Second Science. I'm Christopher Intagliata. So here's the gamble: 20 bucks guaranteed. . . or a 50–50 chance of winning 60 bucks?

Which would you choose? The answer might actually be evident in a brain scan,

according to a study in which researchers posed actual terms like that to 108 young adults-and the stakes were real. The initial choice and then the outcome if they picked the bet determined how much they'd walk away with, after the study.

The research is in the journal Neuron. It does work out in our favor that people are risk averse

because it means on average we're going to be paying people less, they win would otherwise. Joe Kable, a psychologist and neuroscientist at the University of Pennsylvania.

After he and his team recorded the subjects' appetite for risk, they scanned their brains using various techniques that visualize anatomy and real-time activity.

And they found that individuals who were willing to throw the sure-thing $20 away for the chance of a higher payout were more likely to have larger amygdalas-that's a region associated with processing fear, and weighing risk versus reward.

They also saw in the gamblers' brains more synchronized activity between the amygdala and another region, called the medial prefrontal cortex. But there were fewer physical, white matter, connections between those two regions. Which might seem paradoxical.

To a first pass intuition you might expect, well, you know, shouldn't these two be going together? But Kable explains that even though you start out life with lots of those white matter connections,

they tend to get trimmed and refined during development. So fewer physical connections between regions could actually indicate a more mature, more developed synchronization of activity between them.