Abstract
Feature binding refers to the process by which the individual features of a stimulus are combined into an object representation. Previous research suggests that features may be initially bound via their shared location, although location becomes less crucial once visual working memory (VWM) representations are established. Task-irrelevant location changes become less disruptive to color-shape binding memory as the retention interval increases, suggesting that object information is abstracted from location over time (Treisman & Zhang, 2006). To determine whether task-irrelevant changes in color or shape can also be ignored at longer delays, Logie et al. (2011) examined the effect of randomizing of task-irrelevant features at test across different study-test intervals. When remembering color-shape, color-location or shape-location bindings, randomizing along the task-irrelevant dimension was detrimental at shorter (~0-1000 ms), but not at longer study-test intervals (>1000 ms). They concluded that all features were rapidly integrated into objects during perception; however, once in VWM, top-down control mechanisms can be used to suppress the task-irrelevant feature representation, eliminating the detrimental randomization effect at longer intervals. To test the role of top-down control processes in the inhibition of task-irrelevant features during VWM maintenance, we replicated this color-location binding task, but included a concurrent attention load on half the trials (counting backward by threes). We hypothesized that task-irrelevant changes in shape would disrupt color-location binding memory at short, but not long, study-test intervals, but that this would only be observed when executive resources were available to inhibit the task-irrelevant dimension (i.e., no attention load). Contrary to our predictions, we found that task-irrelevant shape changes disrupted color-location binding memory at all delay intervals (250, 750, 1250, 1750 ms), irrespective of load. These results suggest that feature binding in VWM is sensitive to changes in task-irrelevant properties of objects stored in VWM, contrary to previous findings.
Meeting abstract presented at VSS 2016