Seeing the Whole Picture, and Then Some

Courtesy of Jason Kusler

A quarterback decides where to throw the football based on the field's layout and the players' positions on it. Scanning the field, he sees loads of images that help him make his split-second decisions. He actually views even more that he may not recall.

René Marois of Vanderbilt University, Nashville, Tenn., and colleagues study the delicate balance between seeing, registering, and recalling images in the visual field. If images come faster than two per second, subjects often blink and miss the second image. But, says Marois, "The images that are not perceived are actually stored in the brain. There is a trace."

The researchers found that the unperceived images could stimulate the temporal cortex neurons in the back of the brain,¹ but not enough for total recall. "The long-term memory of them is probably weak or nonexistent," says vision expert Robert Desimone of the...