The Extrafoveal Preview Effect is More Pronounced at Polar Angle Locations Where Perception is Poor

Abstract

AbstractThe pre-saccadic preview of a peripheral target enhances the efficiency of its post-saccadic processing, termed the extrafoveal preview effect. Peripheral visual performance –and thus the quality of the preview– varies around the visual field, even at iso-eccentric locations. To investigate whether these polar angle asymmetries influence the preview effect, we asked human participants (N=14) to preview four tilted Gabors at the cardinals, until a central cue indicated to which one to saccade. During the saccade, the target orientation either remained or was flipped (valid/invalid preview). After saccade landing, participants discriminated the orientation of the (briefly presented) second Gabor. Gabor contrast was titrated with adaptive staircases. Valid previews increased participants’ post-saccadic contrast sensitivity. This preview effect was inversely related to polar angle perceptual asymmetries; largest at the upper, and smallest at the horizontal meridian. Our finding reveals that the visual system compensates for peripheral asymmetries when integrating information across saccades.