Why Do People Move Their Eyes When They Think?

The saccadic eye movements that people make when thinking have been largely ignored in the eye-movement literature. Nevertheless, there is evidence that such eye movements are systematically related to internal thought processes. On average, people move their eyes about twice as often when searching through long-term memory as they do when engaged in tasks that do not require such search. This pattern occurs when people are in face-to-face situations, when they are in the dark, and when they have their eyes closed. Because these eye movements do not appear to serve visual processing, we refer to them as "nonvisual" eye movements and discuss why the eyes move during thinking that does not involve vision.