Abstract
The ability to limit distracter interference is an essential aspect of attentional control. However, the mechanisms by which we actively reject non-target objects that have already captured our attention (e.g., a tomato when looking for an apple) are unknown. We hypothesize that the ability to reactively reject non-targets depends upon the ability to control attentional shifting (cf. attentional focus). We tested the relationship between attentional capture by target-similar objects and the ability to reactively shift attention in two experiments. In experiment 1, subjects engaged in a detection task for a target defined by a conjunction of color (e.g., orange) and location (e.g., on the left). On some trials, a target-colored item appeared in an irrelevant location; on those trials, subjects were slower to decide that a target was absent than when the target-colored item was absent. Interestingly, the RT cost of attentional capture by the target-colored distracter was negatively correlated with the individual ability to control attentional shifting, but not to control attentional focus, as measured by the Derryberry Attentional Control Scale. The ability to limit interference by the target-colored distracter was related to an individual’s ability to shift attention; in contrast, better ability to focus attention did not correlate with improved distracter suppression. In experiment 2, we used a visual search task where the target was defined by a conjunction of color and the location of a "gap". In this study, eye-movements were used as an index of attention. We found that the ability to reject distracters by shifting attention depended not only on the similarity of the item with the target, but also the presence of alternative potential targets. This suggests that the ability to reject a distracter is an active process that is associated with selection mechanisms that drive attention towards other goal-relevant objects.
Meeting abstract presented at VSS 2012