Investigating the time course of luminance and orientation influences on saccadic behavior

• DOI: 10.1167/14.10.748
• Publication Date: 2014-08-24T00:18:30Z
• Authors: D. MASSENDARI; C. TANDONNET; E. CASTET; F. VITU
• Keywords: Superior colliculus

Visual features such as luminance and orientation are known to influence oculomotor behavior. However, suggested in models of saccade generation, they may intervene with different time courses, through respectively direct (retinal) vs. indirect (retino-cortical -V1) projections the Superior Colliculus. To test this hypothesis, we compared required initiate a toward peripheral visual target that was defined either by its average or relative textured background. In first experiment, used forced-choice task (Kirchner & Thorpe, 2006), which appeared randomly left right an initial fixation cross, at variable eccentricity. The vertical array Gabor patches whose background (a grid 25°-tilted patches) were varied (method constant stimuli). This allowed us estimate for each participant, luminance/orientation thresholds yielded correct direction 98% cases, hence determine levels made targets equally salient. second then measured saccadic reaction times (SRT) these salience-matched, targets. We observed SRT longer orientation- luminance-defined Irrespective eccentricity, individual distributions shifted about 20 ms on average, towards latencies targets, while accuracy remained unaffected. Thus, intervenes later than determining when eyes move, probably result neural substrates involved extraction two features, slightly route SC luminance. Implications eye guidance natural scenes, where presumably contribute will be discussed. Meeting abstract presented VSS 2014