Visual stability: Retinal and extra-retinal factors

Purpose. To investigate the mechanisms underlying perceptual stability across saccades by examining the detectability of intra-saccadic picture shifts. Methods. Subjects viewed fullcolor displays of naturalistic scenes on a computer monitor while their eye position was monitored by a Dual Purkinje Eyerracker. During a subject's saccade to a target object, the entire scene displaced either in the direction of the saccade or against the direction of the saccade. Subjects reported whether they detected any displacements. Re sut Is. Both saccade length and landing position relative to tha post-shift target object influenced the detection of intra-saccadic stimulus shifts. Conclusions. The perception of a stable visual world across saccades depends on two kinds of mechanisms: a retinal based mechanism and an extra-retinal sased mechanism.