Abstract
Saccadic eye movements, which typically occur two to three times every second, dramatically change the images on the retina; however, conscious perception is stable and continuous. One possible explanation for visual stability is the predictive remapping mechanism. Although previous works have found evidence for predictive remapping of attention pointers and attended features, no study has examined the existence of the predictive remapping of unattended features before a saccade. This would be helpful to discriminate two remapping mechanisms: activation transfer (attention is necessary) and shifting receptive fields (attention is not necessary). In this study, we used the psychophysical adaptation technique to measure aftereffects, including the tilt aftereffect (TAE), the motion aftereffect (MAE) and the threshold elevation aftereffect (TEAE) at the remapped location of an adapting stimulus before a saccade. Subjects first adapted to a peripherally presented stimulus. After a saccadic cue, subjects needed to execute an eye movement to a saccadic target and perform a visual task at the remapped location of the adaptor for measuring the aftereffects just before the saccade. Because the adaptor disappeared before the occurrence of the saccade cue, there was no attention to the adapted feature immediately before and during the saccade. We found a significant TAE and MAE at the remapped location, but no TEAE. These findings imply that extrastriate areas (but not the striate area) could remap visual features, even without attention. Furthermore, we found that the TAE magnitude increased with the interval between the onset of the saccadic target and the onset of the saccadic cue. This finding suggests that the aftereffect at the remapped location develop slowly before the saccade. Taken together, our results provide further psychophysical evidence for the shifting receptive field mechanism of remapping.
Meeting abstract presented at VSS 2014