Your Brain on Snakes

Picture this: You are confined in an MRI machine. Just beyond your head is a live snake, and every time you press a button, the slithering reptile inches closer. You cannot run. You cannot move. You must be absolutely still while the MRI scans your brain to reveal the neurological intricacies of your total freak-out.

Is this a page from Stanley Milgram's to-do list? A torture scene from some straight-to-DVD Indiana Jones movie? No. It is a real experiment led by scientists at the Weizmann Institute in Israel and published last month in the journal Neuron. The goal: To pinpoint courage in the brain. That's a tall order for a lab experiment-- most true acts of courage don't happen in controlled settings--but the investigators hit on a novel solution, as they explain in this video:

Subjects, split into snake-averse and snake-amenable groups, were strapped into the MRI. At the opposite end of the machine's claustrophobia-inducing tube, a "live, rather big" (but not dangerous) snake was Velcroed to the top of a plastic box set on a moveable trolley. Subjects were was asked to fight their fear and, using a handheld button that controlled the position of the trolley, bring the snake just as close to their heads as they could without running screaming out of the MRI. They could watch the snake's progress using a mirror set into the MRI apparatus.

Subjects were also wired up with sweat-measuring electrodes, and they reported their perceived anxiety levels over the course of the experiment. The researchers discovered that our brains don't always agree with our bodies: Some subjects said they were terrified, but didn't sweat much at all. Others had the opposite response. In both cases, an area of the brain called the subgenual anterior cingulate cortex was activated, and subjects were able to move the creepy critter closer.

Subjects' courage buckled when their brains and bodies aligned--that is, when they reported feeling anxious and sweated up a storm. So how can you harness the power of your subgenual anterior cingulate cortex to overcome fear? We're not quite there yet. But the study gives scientists a target for treating patients with debilitating anxiety.

(Curious why snakes give us the heebie-jeebies? Anthropologist Lynne Isbell has a hypothesis.)

User Comments:

Sounds fascinating though I have to wonder how the snake felt about being "velcroed to the top of the box".

Also, did they have in their group those who have no fear of being close to snakes?

Love it!

No problem. I love snakes. They are fascinating and very interesting fellow beings. I believe that this would make being stuck in the MRI a lot more interesting. All creatures have souls and this would be an opportunity for some soul time.

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