Effects of perceptual context on transsaccadic visual matching

Abstract

Transsaccadic visual matching refers to the phenomenon in which presaccadic signals at the location ofthe saccade goal influence the visibility ofpostsaccadic test signals presented at the fovea (Juttner & Rohler, 1993).The present study uses variations ofthe perceptual context, provided by the structure of the presaccadic stimulus display, to investigate the influence of spatial information, decision factors, and visual attention on this form of transsaccadic information processing. The experiments yielded the following results: First, analysis of the data in terms of signal detection theory revealed that transsaccadic visual matching manifests in a shift of decision criterion ({3) rather than in a change of sensory sensitivity (d'). The criterion shift leads to a suppression ofpostsaccadic stimulus information that is incompatible with presaccadic processed information. Second, the matching effect strongly depends on the structure of the presaccadic display, which suggests that mechanisms of visual attention provide the spatial binding of pre-and postsaccadic stimulus information. Third, transsaccadic matching is phenomenologically tied to the execution of the saccade and effective during a postsaccadic period extending up to 160msec after termination of the eye movement. These findings indicate a form of context-sensitive evaluation process that could subsidize the maintenance of visual stability.When we look at pictures or scan our visual environment, our eyes are almost permanently moving. Fast ballistic eye movements, or saccades, separate brief periods of time (fixations) during which the eyes remain almost stationary. During the saccade, vision is severely impaired. Saccadic suppression (see, e.g., Riggs, Merton, & Morton, 1974;Volkman, Schick, & Riggs, 1968) reduces visual sensitivity and suppresses the perception of the smeared retinal image during the eye movement. Moreover, sensitivity to displacement of targets decreases substantially so that motion and position information becomes severely degraded (Bridgeman, 1983;Bridgeman, Hendry, & Stark, 1975). Acquisition ofvisual information therefore takes place mainly during the fixations, and the sequence of fixational pauses corresponds to a series of discrete retinal images. Even if we assume a stationary head and body, the retinal projections still differ from each other as the mapping of spatiotopic to retinal coordinates depends on the dynamic position of the eye. But despite these differences, the apparent position of objects in the world remains constant and our experience ofthe world is stable and continuous rather than being fragmented into individual glimpses.

Perceptual continuity across saccades

“…Within a single fixation, presaccadic information should be updated and be available directly after the saccade. In Chapter 2, we demonstrate a direct link between the motion information in the presaccadic and immediate post-saccadic information, as hypothesized from the results earlier studies (Deubel, Bridgeman, & Schneider, 1998;Jüttner, 1997). However, it has been suggested that spatiotopic updating can only be observed when the saccade can be planned for 500 ms or more Zimmermann, Morrone, Fink, et al, 2013).…”

“…Second, spatiotopic updating can develop quickly. Specifically, the results show that post-saccadic perception immediately after saccade offset is influenced by the pre-saccadic stimulus (Deubel et al, 1998;Fornaciai et al, 2018;Jüttner, 1997). Moreover, in the integration of pre-and post-saccadic visual information, the weight of the pre-saccadic stimulus -this stimulus is presented in the peripheral visual field, and earliest in time -is lower than that of the post-saccadic stimulus…”

“…Within a single fixation, pre-saccadic information should be updated and be available directly after the saccade. Concerning the post-saccadic availability, different experiments demonstrated that spatiotopic updating primarily affects perception immediately after saccades (Deubel et al, 1998(Deubel et al, , 1996Jüttner, 1997). But concerning the pre-saccadic updating of visual information, spatiotopic representations have been estimated to develop surprisingly slow, requiring fixation durations of more than 500 ms (Nakashima & Sugita, 2017;Zimmermann, Morrone, & Burr, 2015, 2013Zimmermann, Morrone, et al, 2014;Zimmermann, Morrone, Fink, et al, 2013).…”

Deictic codes, embodiment of cognition, and the real world

“…However, concerning the aspect of spatial generalization, that is, the application of previously learned concepts across the visual field, the situation is different. Further support comes from observations concerning the transsaccadic processing of visual information ( Jüttner & Röhler 1993;Jüttner 1997). The finding of a partial generalization of learned categorical concepts stands in contrast to the failure to obtain shift-invariance concerning the discrimination of random binary patterns (Nazir & O'Regan 1990).…”

Time course of spatiotopic updating across saccades

“…Within a single fixation, presaccadic information should be updated and be available directly after the saccade. Concerning the postsaccadic availability, different experiments demonstrated that spatiotopic updating primarily affects perception immediately after saccades (20,(34)(35)(36). However, concerning the presaccadic updating of visual information, spatiotopic representations have been estimated to develop surprisingly slowly, requiring fixation durations of more than 500 ms (37)(38)(39)(40)(41).…”