Print

Email story

Comment

Email editor

Different brain regions focus and distract

The findings could lead to better treatments for attention deficit disorder, researchers say.

By ASSOCIATED PRESS
Published March 30, 2007

WASHINGTON - Spot a bear in the woods, and a different part of your brain will yell "pay attention" than if you were studying bears at the zoo.

Research shows it takes one part of the brain to start concentrating and another to be distracted. This discovery could help scientists develop better treatments for attention deficit disorder.

"This ability to willfully focus your attention is physically separate in the brain from distracting things grabbing your attention," said Earl Miller, a neuroscientist at the Massachusetts Institute of Technology. He led the study, published in today's edition of the journal Science.

There are two main ways the brain pays attention: "top down" or willful, goal-oriented attention, such as when you focus to read, and "bottom-up" or reflexive attention to sensory information - loud noises or bright colors or threatening animals.

Likewise, there are different degrees of attention disorders. Some people have a hard time focusing, while others have a hard time filtering distractions.

Scientists knew paying attention involved multiple brain regions but did not know how, because studies until now have examined one region at a time.

Miller hooked painless electrodes onto monkeys to track how two key areas react together when the brain jumps to attention.

The electrical activity in the concentration (prefrontal cortex) and distraction (parietal cortex) areas began vibrating in synchrony as they signaled each other. But it was at different frequencies.

Sustaining concentration involved lower-frequency neuron activity. Distraction occurred at higher frequencies. So, Miller concluded, scientists one day might find a treatment that essentially turns up or down the volume to boost attention.

The result raises logical questions. Once the parietal lobe recognizes something, how does it evaluate what's important enough to focus on - and thus signal other brain regions to join in - and what was a distraction that can be ignored?

It is the snap judgment that determines if a loud beeping is a fire alarm you should heed or just another car alarm down the street - or if that bear down the trail is going to be a threat or is already ambling away.

[Last modified March 30, 2007, 01:28:36]