Eye movements during the viewing of Necker cubes.

Eye movements were recorded while subjects viewed a Kopfermann-like series of Necker cubes and signaled perceptual reversals. At the instant of reversal, subjects tend to fixate the vicinity of the externally appearing corner. These fixations at the instant of reversal tend to have longer duration than those immediately before or after. The longer fixation times associated with pperceptual reversal probably reflect the time required to construct the alternate three-dimensional interpretation of the cube. After construction of this new model, the subject then fixates the vicinity of the newly interpreted externally appearing corner.