Visual working memory enhances target discrimination accuracy with single-item displays

Memory-driven capture during focused visual attention

Attention can be captured by the presence of distractors that match the current content of working memory in the visual field. This memory-driven capture is well established when observers adopt diffused attentional settings prior to the onset of memory-matching distractors. However, it remains unclear whether memory-driven capture can occur when observers are in a state of focused attention. The present study attempted to address this question by examining whether memory-matching distractors can disrupt performance on a focused attention task. Participants were asked to hold a sample word in working memory and then had to name a central color while ignoring an irrelevant distractor word in the visual display. In Experiments 1 and 2, the distractor word was always presented centrally within the focus of attention. In Experiment 3, the distractor word could be presented either at the center or at the periphery (i.e., outside the focus of attention). The results showed that the irrelevant distractor word within the focus of attention interfered with color-naming performance when it matched the sample word held in working memory. However, no interference effect was observed when the distractor word was presented outside the attentional focus. The present findings indicate that working memory-driven capture during a state of focused visual attention depends crucially on whether or not memory-matching distractors are positioned within the focus of attention.

The presence of a distractor matching the content of working memory induces delayed quitting in visual search

Previous research has shown that the presence of a distractor object matching the current content of working memory interacts with visual search. Because finding a target and quitting a search without finding a target may be implemented by qualitatively different processes, it is possible that the effects of a memory-matching distractor on target-present trials and on target-absent trials reveal different mechanisms by which the memory-matching distractor interacts with visual search. Although previous studies have well established the effect of attentional capture by a memory-matching distractor when the target object is found in the search display, there remains an open question about whether the presence of a memory-matching distractor can affect the process of search termination when no target is found. In the present study, we showed that search termination times on target-absent trials were delayed by the presence of a distractor matching the content of visual working memory. This delayed quitting effect cannot be conceived of as a more general influence of visual short-term memory, because the presence of a distractor matching the content of passive visual short-term memory (i.e., visual priming) did not influence quitting behavior in visual search. These findings offer a novel perspective that distractors matching the information maintained in visual working memory can cause observers to delay search termination when no target has been found.