Saccadic eye movements smear spatial working memory.

Abstract

Why do saccades interfere with spatial working memory? One possibility is that attention and saccades are tightly coupled, and performing a saccade momentarily removes attention from spatial working memory, degrading the memory representation. This cannot be the entire explanation, because saccades cause greater interference than do covert attentional shifts (Lawrence, Myerson, & Abrams, 2004). In addition, this saccadic degradation is limited to spatial but not object, configural, or verbal representations. We propose that saccadic remapping is partially responsible for this increased interference. To test this, we used a spatial change detection task, and during the retention interval, participants either performed a central task, a peripheral task without an eye movement, or a peripheral task that required a saccade. Using the method of constant stimuli allowed us to fit psychophysical functions in which we derived measures of spatial memory precision, guessing, and response bias. It is important that we found a directionally specific loss of memory precision, such that memory representations were less precise along the axis of the saccade. This was beyond the general loss of precision we found for covert shifts, suggesting that part of the effect is because of remapping. Saccades also increased guessing, but unlike the loss of precision, the effect was nondirectional. (PsycINFO Database Record (c) 2019 APA, all rights reserved).