Research Article Reward Priority of Visual Target Singletons Modulates Event-Related Potential Signatures of Attentional Selection

ABSTRACT—We examined visual search for color singleton targets, whose shape was discriminated. Critically, we varied the reward priority of singleton colors (correct fast performance was worth more bonus points for red single-tons than for green singletons, or vice versa) to test wheth-er event-related potential signatures of visual selection can be affected by distinct reward priorities for different target types, even when every target has to be selected for report. The N2pc component was earlier and larger for high- than for low-reward targets. This influence of reward on the N2pc correlated with the subject-by-subject impact of reward level on efficiency of behavioral perfor-mance. Later postselection processing was also affected by reward level. These results demonstrate that visual selection of task-relevant items is rapidly modulated by reward-related priorities, evenwhen every target has to be selected for response. Visual processing does not depend solely on current retinal inputs, but is known to be modulated also by attentional factors (i.e., task-relevant vs. task-irrelevant status of competing in-puts) and by emotional factors (i.e., affective or reward-related status of those inputs), which might be conceived broadly as reflecting ‘‘cold’ ’ and ‘‘hot’ ’ aspects of cognition, respectively (for a review, see Vuilleumier & Driver, 2007). Numerous functional neuroimaging and event-related potential (ERP) studies have now documented attentional (task-relevance) in-fluences on visual processing (for reviews, see, e.g., Kastner &amp