EXTRA-OCULAR FEEDBACK IN BINOCULAR RIVALRY.

Abstract

Current theorizing has led to the proposal that feedback from contour scanning eye nlovements plays a role in the visibility of the contour scanned. It is assumed that a central mechanism establishes match or mismatch relations between the pattern of stimulation fed back from the extra-ocular muscles and the many patterns of stimulation that may arise from scanning one contour in a field of many. The particular retinal stimulations that match extra-ocular feedback are enhanced in visibility. Thus, in regard to binocular rivalry, rhe expectation is that the stimulus seen on initial viewing will be the one that matches contemporaneous extra-ocular feedback. To test this expectation, binocular rivalry was induced by having S view stereoscopically the red vertical and green horizontal members of a cross. In two previewing conditions, S scanned for 30 sec. with eyes closed. In one condition S scanned vertically and in the other condition, S scanned horizontally. Thus, when S opens his eyes to view the two stimuli, preview conditions have provided, it is assumed, aftereffects of feedback from scanning. These aftereffects provide the hypothesized match with one of the two stimuli presented, viz., vertical preview with vertical stimulus and horizontal preview with horizontal stimulus. All Ss were practiced in reporting by telegraph key the duration that one stimulus was seen alone or in front of the other stimulus. Ss were tested twice for each preview condition. A Latin square design controlled for sequence of conditions within two double fatigue orders.