Gorilla experiment

Subjects in one experiment, as reported in Scientific American in March 2004, were told to focus on how many passes a basketball team made in a one-minute video. About halfway through the video, a gorilla emerged and walked across the basketball court. Half the participants in the experiment did not see the gorilla. The more you focus on something, the less able you become to see unexpected or unanticipated happenings. Just as when you drive you have to frequently use the rear- and side-view mirrors while focusing on the road ahead, so do you have to make yourself aware, even if only peripherally, of what may be coming up alongside or behind you.