Inattentional Blindness: Why We Miss What We're Not Looking For

In 1999, Daniel Simons and Christopher Chabris asked subjects to count basketball passes in a video. A person in a gorilla suit walked through the scene for nine seconds, beat their chest, and walked off. Half of all subjects never saw it. Inattentional blindness: when attention is focused on a task, objects outside that focus — even conspicuous ones — become literally invisible. The science with consequences for aviation, medicine, driving, and security.