Saccade Preparation Reshapes Sensory Tuning.
Human observers make large rapid eye movements-saccades-to bring behaviorally relevant information into the fovea, where spatial resolution is high. In some visual tasks [1-4], performance at the location of a saccade target improves before the eyes move. Although these findings provide evidence that extra-retinal signals evoked by saccades can enhance visual perception, it remains unknown whether and how presaccadic modulations change the processing of feature information and thus modulate visual representations. To answer this question, one must go beyond the use of methods that only probe performance accuracy (d') in different tasks. Here, using a psychophysical reverse correlation approach [5-8], we investigated how saccade preparation influences the processing of orientation and spatial frequency-two building blocks of early vision. We found that saccade preparation selectively enhanced the gain of high spatial frequency information and narrowed orientation tuning at the upcoming saccade landing position. These modulations were time locked to saccade onset, peaking right before the eyes moved (-50-0 ms). Moreover, merely deploying covert attention within the same temporal interval without preparing a saccade did not alter performance. The observed presaccadic tuning changes may correspond to the presaccadic enhancement [9-11] and receptive field shifts reported in neurophysiological studies [12-14]. Saccade preparation may support transaccadic integration by reshaping the representation of the saccade target to be more fovea-like just before the eyes move. The presaccadic modulations on spatial frequency and orientation processing illustrate a strong perception-action coupling by revealing that the visual system dynamically reshapes feature selectivity contingent upon eye movements.
Department of Psychology, New York University, 6 Washington Place, New York, NY 10003, USA. Electronic address: hsin.hung.li@nyu.edu.
Hsin-Hung
HH
Li
Department of Psychology, New York University, 6 Washington Place, New York, NY 10003, USA; Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, NY 14642, USA; Center for Visual Science, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA.
Antoine
A
Barbot
Department of Psychology, New York University, 6 Washington Place, New York, NY 10003, USA; Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
Marisa
M
Carrasco
D000328:Adult; D006801:Humans; D000072458:Orientation, Spatial; D012438:Saccades; D014796:Visual Perception; D055815:Young Adult