Blinding distractions

By HSC Staff Writer • Published: April 20th, 2006
Category: Health in a Heartbeat

Magicians say the hand is quicker than the eye. But scientists say it isn’t the eye’s fault that we can’t see how an illusionist cuts a dollar bill into pieces, only to restore it, fully intact.

It’s the brain that can’t keep up.

British scientists say magicians are so skilled at distracting our brains with dramatic movement, we become mentally incapable of noticing obvious visual changes.

It happens all the time behind the wheel. A visually startling billboard or cell-phone conversation interferes with a driver’s mental focus, and all of a sudden two cars are sharing space with one another.

This phenomenon of becoming oblivious to your surroundings is called “change blindness.” Researchers decided to investigate with a bit of experimental sleight of hand.

Using a classic attention test, scientists flashed pictures of faces in front of volunteers, who pressed a key whenever they see changes in facial expression. It’s easy.

But when scientists add even the slightest distraction, such as a simple flicker between two of the images, the volunteers don’t recognize the change.

Investigating further, scientists traced “change blindness” to the parietal [pah-RYE-ih-tal] cortex, which is traditionally not associated with vision.

It turns out it’s the brain that’s playing tricks on us.

In the end, the research shows it takes only a moment’s distraction to completely disrupt our awareness.

So if you’re driving, remember this: It’s not enough to keep your eyes on the road. You’ve got to keep your attention and your parietal cortex there, too.