Pre-saccadic perception: separate time courses for enhancement and spatial pooling at the saccade target

Buonocore, A., Fracasso, A. and Melcher, D. (2017) Pre-saccadic perception: separate time courses for enhancement and spatial pooling at the saccade target. PLoS ONE, 12(6), e0178902. (doi: 10.1371/journal.pone.0178902) (PMID:28614367) (PMCID:PMC5470679)

Abstract

We interact with complex scenes using eye movements to select targets of interest. Studies have shown that the future target of a saccadic eye movement is processed differently by the visual system. A number of effects have been reported, including a benefit for perceptual performance at the target (“enhancement”), reduced influences of backward masking (“unmasking”), reduced crowding (“un-crowding”) and spatial compression towards the saccade target. We investigated the time course of these effects by measuring orientation discrimination for targets that were spatially crowded or temporally masked. In four experiments, we varied the target-flanker distance, the presence of forward/backward masks, the orientation of the flankers and whether participants made a saccade. Masking and randomizing flanker orientation reduced performance in both fixation and saccade trials. We found a small improvement in performance on saccade trials, compared to fixation trials, with a time course that was consistent with a general enhancement at the saccade target. In addition, a decrement in performance (reporting the average flanker orientation, rather than the target) was found in the time bins nearest saccade onset when random oriented flankers were used, consistent with spatial pooling around the saccade target. We did not find strong evidence for un-crowding. Overall, our pattern of results was consistent with both an early, general enhancement at the saccade target and a later, peri-saccadic compression/pooling towards the saccade target.

• Item Type: Articles
• Additional Information: The research was supported by a European Research Council (ERC) grant (grant agreement no. 313658) awarded to DM. AB was funded by a research fellowship from the Autonomous Province of Trento through the call “Grandi Progetti 2012”, project “Characterizing and improving brain mechanisms of attention – ATTEND”.
• Keywords: Adult, backward masking, controlled study, crowding (vision), eye fixation, eye movement, female, forward masking, human, human experiment, male, normal human, saccadic eye movement, task performance, visual discrimination, visual orientation, depth perception, perception, photostimulation, procedures, reaction time, vision, visual system function, young adult, adult, female, humans, male, ocular physiological phenomena, perceptual masking, photic stimulation, reaction time, saccades, space perception, visual perception.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fracasso, Dr Alessio
• Authors: Buonocore, A., Fracasso, A., and Melcher, D.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2017 Buonocore et al.
• First Published: First published in PLoS ONE 12(6): e0178902
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.17605/OSF.IO/5YJHC