Abstract
A set of experiments examined the effect of an attentionally salient distractor item on target shape discriminations (i.e., orientation of a T). Previous research has found that target discriminations are impaired when the target is near an attentionally salient distractor, such as a color singleton or an abrupt onset (e.g., Mounts, 2000, P&P). The current experiments manipulate the relative attentional salience of the distractor item and the target to determine the effects on this Localized Attentional Inhibition (LAI). Both stimulus-based (e.g., size changes) and strategic (e.g., probability) manipulations were used to manipulate the attentional salience of target and distractor items. The results suggest that LAI occurs when the distractor has greater attentional salience than the target. As the attentional salience of the target is increased relative to the distractor, LAI diminishes and eventually disappears. If the relative attentional salience of the target is further increased, the pattern reverses, and target performance is facilitated when the target neighbors an attentionally salient distractor. This pattern of results obtains for both stimulus-based and strategic manipulations of relative distractor and target attentional salience. The results suggest the operation of two attentional mechanisms: a preparatory attention mechanism that facilitates the processing of items in a given region, and a selective attention mechanism that inhibits the processing of items neighboring an attentionally selected item, with relative attentional salience governing initial selection.