Transsaccadic integration benefits are not limited to the saccade target

Emma E M Stewart,Alexander C Schütz

doi:10.1152/jn.00420.2019

Abstract

Across saccades, humans can integrate the low-resolution presaccadic information of an upcoming saccade target with the high-resolution postsaccadic information. There is converging evidence to suggest that transsaccadic integration occurs at the saccade target. However, given divergent evidence on the spatial specificity of related mechanisms such as attention, visual working memory, and remapping, it is unclear whether integration is also possible at locations other than the saccade target. We tested the spatial profile of transsaccadic integration, by testing perceptual performance at six locations around the saccade target and between the saccade target and initial fixation. Results show that integration benefits do not differ between the saccade target and surrounding locations. Transsaccadic integration benefits are not specific to the saccade target and can occur at other locations when they are behaviorally relevant, although there is a trend for worse performance for the location above initial fixation compared with those in the direction of the saccade. This suggests that transsaccadic integration may be a more general mechanism used to reconcile task-relevant pre- and postsaccadic information at attended locations other than the saccade target.NEW & NOTEWORTHY This study shows that integration of pre- and postsaccadic information across saccades is not restricted to the saccade target. We found performance benefits of transsaccadic integration at attended locations other than the saccade target, and these benefits did not differ from those found at the saccade target. This suggests that transsaccadic integration may be a more general mechanism used to reconcile pre- and postsaccadic information at task-relevant locations.

Highlights

As humans move their eyes across the visual field, upcoming saccade targets are selected using low-resolution peripheral vision and subsequently brought under higher resolution foveal scrutiny after the saccade ends
The results of this study suggest that transsaccadic integration, i.e., an increase in transsaccadic performance compared with pre- and postsaccadic performance, can occur at locations other than the saccade target when the integration location is behaviorally relevant, and that integration benefits at locations surrounding the saccade target do not differ from those at the saccade target itself
This is consistent with studies showing that integration can occur beyond the saccade end point (Schut et al 2018) and with studies showing that integration of location information can occur across the visual field across saccades; for example, Prime et al (2006) demonstrated that integration occurs beyond the fovea, in the absence of any common visual cues between pre- and postsaccadic vision, suggesting that integration may occur in a broader manner across the visual field and may rely on internal oculomotor signals to align the pre- and postsaccadic stimuli

Summary

Introduction

As humans move their eyes across the visual field, upcoming saccade targets are selected using low-resolution peripheral vision and subsequently brought under higher resolution foveal scrutiny after the saccade ends. Recent studies have provided evidence for the fusion of pre- and postsaccadic stimulus properties (Paeye et al 2017) and have suggested that our postsaccadic percept is influenced by presaccadic stimulus properties (Fabius et al 2016, 2019) These studies all contravene earlier claims against transsaccadic integration (i.e., O’Regan and Lévy-Schoen 1983; Rayner and Pollatsek 1983) and provide converging evidence that transsaccadic integration is possible and that our ultimate percept of a saccade stimulus depends on both pre- and postsaccadic information. We showed (Stewart and Schütz 2019) that integration benefits can occur for locations along the saccade trajectory, even when the pre- and postsaccadic stimuli are processed in different hemifields

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