Models of the mechanism underlying perceived location of a perisaccadic flash

A variety of experiments have shown that subjects tend to perceive a target flash as mislocalized when the flash is presented just before, during or shortly after the occurrence of a saccade. The characteristics of this mislocalization suggest that it arises from an anticipatory, slow extraretinal signal, i.e., the signal starts to change before a saccade and continues to change during and after the saccade. However, a target flash creates a visual signal that can persist for as long as 300 ms. Interaction of this visual persistence with the extraretinal signal could have a significant influence on the perceived location of the target flash, and thus on features of the extraretinal signal as inferred from the perceived location. In this study, several different types of models were used to explore how retinal signal persistence together with an extraretinal signal might affect perception. According to these models, the anticipatory, slow extraretinal signal may be an artifact of using a target flash, and the actual extraretinal signal may begin to change only after saccade onset and relatively quickly.