Racy and Gory Images Cause Temporary Blindness

Aug. 17, 2005 — -- Here's the scene: You've seen a flash of nudity on the telly just as your sweetie walks in the room, and you don't even notice the love of your life.

It's a bad scene, but hey, you're innocent. You've just been hit by something researchers call "emotion-induced blindness."

It's not a serious disease, unless your sweetie has a powerful right hook, but new research shows that instantly after seeing an erotic image, or a violent scene, we wouldn't notice a building lying on its side. Literally.

Psychologists at Vanderbilt and Yale universities have been studying the effect that highly emotional images have on our perception of the world around us. And they've found convincing evidence that the human brain just can't process information that it receives immediately after seeing a violent or erotic scene.

We're talking real short term here, around a fifth to a half a second, but given the speed of today's society, that may be enough to worry about. A fast-moving vehicle, for example, can travel a significant distance in that brief span of time.

Psychologists David Zald of Vanderbilt, and Steven Most, Marvin Chun and David Widders of Yale, started by looking at the effect of gory images, like a fatal traffic accident, on the brain's ability to process subsequent information.

They programmed a computer to show a series of images in rapid succession. Each image was shown for precisely 100 milliseconds (one-10th of a second.) Most of the images were neutral, thus requiring no or very little emotional response, but every now and then they tossed in a gory scene.

The computer also flashed pictures of a building lying on its side, and participants in the project were told to indicate with an arrow key which way the building was lying.

That's a pretty easy task, but if the building came a fraction of a second after a gory image, the participants missed it entirely.

"They didn't see it at all," says Zald.