Abstract
Visual attention (VA) and eye-movement control have a strong functional overlap. In addition it has been hypothesized that VA also serves specific functions for encoding or maintaining visual information in working memory. Carbone and Schneider (2010) found that encoding a briefly presented and backward masked letter into WM slows down execution of a trailing reflexive saccade, suggesting that utilization of VA for control of saccades and for control of WM share attentional resources. In order to further elaborate on this interaction we conducted the following dual-task experiments. Task 1 consisted of a memory-guided saccade to a briefly presented peripheral stimulus (T1). For task 2 participants had to report a briefly presented and backward masked letter at fixation (T2). Importantly, the letter was presented during encoding and retention of the saccade-target location. The main independent variable was the onset asynchrony between the stimuli (SOA) of the two tasks. Half of the participants performed task 2 only, i.e. they were instructed to ignore the stimuli of task 1. The proportion of correct letter identification served as the main dependent measure. We found SOA-based interference on the letter identification (T2) performance in all experiments – similar to the second target deficit in Attentional Blink experiments. That is, performance was diminished with short SOA and increased with SOA duration. Moreover, depending on the competition requirements of task 1 (e.g., memory-guided saccade vs. no task 1) a modulation of the basic SOA-dependent interference effect took place. We conclude that encoding of a location for a memory-guided saccade (T1) and encoding of a trailing and masked letter (T2) into WM share common attentional resources.
Meeting abstract presented at VSS 2012