Consider this scenario: You are making dinner. You reach into a crowded kitchen drawer to find a paring knife. As you peel potatoes, you glance over at the basketball game on television to check out your team's performance. When your cell phone buzzes with a text message, you dry your hands and reply, picking out the letters one by one on the screen. These three actions—finding a knife, a moving basketball and letters of the alphabet—seem distinct, but all are examples of what is known in cognitive psychology as visual search—the ability to locate specific items in a crowded scene.
We find things so often and so effortlessly that we take this skill for granted, yet identifying what we are looking for is actually a complex psychological feat. The eyes gather tremendous amounts of sensory information—about color, motion, orientation, shape, light and shadow. The brain's task is to synthesize and prioritize all these data, helping us explore the world safely and profitably. Visual search involves not just sight but memory and abstract thought. We have to hold in mind what we are seeking, acquire a range of visual information, remember what we have seen and compare every new object with our mental target.