Perceptual-blindness experiments challenge the validity of eyewitness testimony and the metaphor of memory as a video recording

Picture yourself watching a one-minute video of two teams of three players each. One team wears white shirts and the other black shirts, and the members move around one another in a small room tossing two basketballs. Your task is to count the number of passes made by the white team — not easy given the weaving movement of the players. Unexpectedly, after 35 seconds a gorilla enters the room, walks directly through the farrago of bodies, thumps his chest and, nine seconds later, exits. Would you see the gorilla?

Most of us believe we would. In fact, 50 percent of subjects in this remarkable experiment by Daniel J. Simons of the University of Illinois and Christopher F. Chabris of Harvard University did not see the gorilla, even when asked if they noticed anything unusual (see their paper “Gorillas in Our Midst”). The effect is called inattentional blindness. When attending to one task — say, talking on a cell phone while driving — many of us become blind to dynamic events, such as a gorilla in the crosswalk. (continue reading…)