Abstract

Inconsistent evidence has been reported regarding the role of visual short-term memory (VSTM) load on attentional selection. Some studies demonstrated that maintaining large amount of information in VSTM enhanced attentional selection. Using similar experimental methods, however, others observed impaired attentional selection by VSTM load. Here, we attempted to replicate previous conflicting results and tested the role of VSTM load as a modulating factor on attentional selection. In Experiments 1~3, participants performed a flanker task while maintaining the colors and locations of visual objects in VSTM for change detection. Irrespective of stimulus configurations, condition orders, and memory set sizes, we failed to find evidence that VSTM load modulates flanker interference. By demonstrating that flanker interference did decrease by perceptual load in Experiment 4, we excluded the possibility that our current attentional selection measure might not be sensitive enough. Experiment 5 manipulated the spatial relationship between memory items and a flanker. When memory items and a flanker appeared on opposite sides of the center, flanker interference increased with VSTM load. When their positions were overlapped, however, flanker interference was not affected by VSTM load. In addition, individual difference analysis failed to find a reliable relationship between VSTM capacity estimates and flanker interference. The equivalence test showed that the modulating effects of VSTM load on flanker interference were only negligible. The current findings provide evidence against the assertion that VSTM load modulates attentional selection, and call for new models within which the dynamic relationships between working memory and visual selection are fully described and tested.