When a stimulus appears in a previously cued location several hundred milliseconds after the cue, the time required to detect that stimulus is greater than when it appears in an uncued location. This increase in detection time is known as inhibition of return (lOR). It has been suggested that lOR reflects the action of a general attentional mechanism that prevents attention from returning to previously explored loci. At the same time, the robustness of lOR has been recently disputed, given several failures to obtain the effect in tasks requiring discrimination rather than detection. In a series of eight experiments, we evaluated the differences between detection and discrimination tasks with regard to lOR. We found that lOR was consistently obtained with both tasks, although the temporal parameters required to observe lOR were different in detection and discrimination tasks. In our detection task, the effect appeared after a 400-msec delay between cue and target, and was still present after 1,300msec. In our discrimination task, the effect appeared later and disappeared sooner. The implications of these data for theoretical accounts of lOR are discussed.Attention is widely presumed to play an important role in the rapid and efficient scanning ofvisual environments. In particular, when search is difficult, the movement of attention from one location to another may improve discrimination at each location, and thus also improve overall search efficiency. However, the efficiency of search also depends on the ability to prevent attention from returning to previously examined locations. This issue has been the focus of considerable study by attention researchers over the past decade.Specifically, it has been shown that response to a target is speeded if the location at which the target appears is precued. In the cost-benefit paradigm (Posner, 1980), subjects are to respond to a target appearing in one of three boxes, one in the center ofthe screen and one to each side of the center. Before the target appears, the subject's attention is cued to one of the two peripheral locations. This attentional cuing is accomplished by making one of the two peripheral boxes flicker briefly. The target then appears in either the cued location (cued trials) or the uncued location (uncued trials). When the cue-target stimulus onset asynchrony (SOA) is less than about 300 msec, responses are faster on cued than on uncued trials.We thank Steven P. Tipper, Bruce Milliken, Arthur F. Kramer, an anonymous reviewer, and especially Raymond Klein for their useful comments. Bruce Milliken also helped improve our English. Pilar Gonzalvo helped us with data collecting. We are grateful to all of them.

No abstract

No abstract

The emotions displayed by others can be cues to predict their behavior. Happy expressions are usually linked to positive consequences, whereas angry faces are associated with probable negative outcomes. However, there are situations in which the expectations we generate do not hold. Here, control mechanisms must be put in place. We designed an interpersonal game in which participants received good or bad economic offers from several partners. A cue indicated whether the emotion of their partner could be trusted or not. Trustworthy partners with happy facial expressions were cooperative, and angry partners did not cooperate. Untrustworthy partners cooperated when their expression was angry and did not cooperate when they displayed a happy emotion. Event-Related Potential (ERP) results showed that executive attention already influenced the frontal N1. The brain initially processed emotional expressions regardless of their contextual meaning but by the N300, associated to affective evaluation, emotion was modulated by control mechanisms. Our results suggest a cascade of processing that starts with the instantiation of executive attention, continues by a default processing of emotional features and is then followed by an interaction between executive attention and emotional factors before decision-making and motor stages.

No abstract