Abstract
Primate visual system has been shown to compensate for eye movement induced retinotopic shifts in the visual image. For instance, neurons with receptive fields coding for post-saccadic retinotopic stimulus location are activated even before a saccade starts. Similarly, spatial attention also predictively shifts to the post-saccadic stimulus location. Such predictive updating of spatial location information is considered to be the mechanism mediating visual stability. However, contributions of attended object features - such as shape or color - have been relatively neglected. We investigated feature based attention across saccades and its potential contributions to visual stability. In this study, we asked participants to do two things at the same time – to make a saccade to a colored dot and to discriminate a probe (a Gabor patch tilted to left or right) presented at a distractor location which either matched or did not match the color of the saccade target. Tilt discrimination performance hence served as a measure of feature based attention - before a saccade started, participants were better at discriminating probes presented at distractor locations that matched the color of the saccade target, than at distractor locations that did not match that color. This is a classic feature attention effect - allocating attention to one feature (color of the saccade target) lead to performance increases at other locations matching that feature (distractor locations matching that color). Importantly, we observed that immediately after the saccade was finished, feature based attention benefits persisted at the distractor location with matching color, regardless of the fact that it now had a different retinotopic position. Thus, feature based attention and predictive shifts of spatial attention could combine to quickly find the location of relevant objects across saccades.
Meeting abstract presented at VSS 2012