Why we worry

Real human brain
A real human brain being displayed as part of new exhibition at the Bristol attraction is seen on March 8, 2011 in Bristol, England.
Matt Cardy/Getty Images

Why do we worry about some things and not others? In a recent New York Times op-ed, David Ropeik notes, "while our choices about risk invariably feel right when we make them, many of these decisions end up putting us in greater peril."

Ropeik, instructor of risk perception and risk communication at the Harvard School of Public Health, joined The Daily Circuit Tuesday to discuss why our fears don't always match up with the facts, and how to make healthier choices in a risky world.

"The part [of the brain] that sets off the fight or flight response gets the information before the parts that think," he said. "So we're built to fear first and think second ... At this point in our evolution, the wiring and chemistry of the brain assures that emotion and instinct can easily overpower reason in the ongoing response."

Joseph LeDoux, professor of neural science and psychology at New York University, also joined the discussion. He said we use the word 'fear' to describe a lot of different things: from a big exam, to flying in an airplane or running into a snake in the woods. We even fear being late to a movie.

"Probably each of those examples I gave is a completely different thing," he said.

"Some are very cognitive and have very little to do with the sort of innate, hard-wired activation of brain circuits that then produce responses," he said. "And then another thing to distinguish is the conscious experience of fear that we have when we encounter something dangerous from our response to it which is controlled by a completely different system. The system that is giving you the conscious experience is basically a subset of the mechanism of consciousness itself. The system that is allowing you to detect and respond to danger is as old as life itself."

A caller from Minneapolis said she worries about things she can control, such as turning off equipment at art school that could harm others.

"I'm never afraid of flying or meteors or natural disasters," she said.

So why are her fears different from those around her?

"The thing we need to recognize is that each of our brains is basically identical in many respects, but also unique in many respects," LeDoux said. "So we all have the same wiring pattern ... but layered on top of that is a vast amount of experience that is tweaking the way our synapses are being shaped and formed so we have these individual differences."

Those differences come from genetics, experiences and chemical makeup, he said.

"We come into any kind of fearful, dangerous experience with a different brain that reacts to it," LeDoux said. "In a horrible, horrific situation like an airplane crash or any other kind of disaster, only a small number of people develop post traumatic stress disorder, about 20 to 30 percent or so. So it's not the disaster that is producing PTSD, so much as the way the person's brain is responding to that disaster."

LeDoux is now working on research on how the brain makes the transition from reaction to action.

"We've been looking at how the brain makes those transitions, what goes on in the Amygdala that switches the brain from a passive coping response, which is freezing, to an active coping response, which is learning to do something that eliminates the fearful stimulus from your life," he said.

LeDoux said he started looking at this after seeing the reaction to the 9/11 attacks.

"People were just sort of stuck in front of the TV watching the flames come out of the buildings over and over and over again," he said. "They knew it wasn't what they should be doing, but they were stuck in this passive coping mode. What the animal research suggests is they should be getting up and doing things because each step away from that passive coping removes the fear and reinforces the next step."

What are your irrational fears? Comment on the blog.

MPR News' Alex DiPalma contributed to this report.

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