Abstract
The selectivity of attention in both space and time is critical for processing our dynamic environment. The load theory of selective attention suggests that the spatial selectivity of attention is increased when the perceptual difficulty of a task increases, resulting in decreased processing of task-irrelevant distractors. In contrast, increasing load on control processes reduces the spatial selectivity of attention, resulting in increased distractor processing (Lavie, 2005). Studies of the attentional blink (AB) have demonstrated that temporal attention also influences distractor processing, such that distractor processing increases during the AB relative to outside the AB (Jiang & Chun, 2001). When considered in the context of load theory, the finding that distractors influence target selection during the AB more than outside the AB is consistent with the notion that the AB reflects a deficit in post-perceptual cognitive processes. Here we investigated the extent to which task-irrelevant distractor processing during the AB is modulated by the difficulty of the first target task. To investigate this issue, the first and second target tasks (T1 and T2) required discriminating the direction of a central arrow that was flanked by distractor arrows pointing in the same direction (easy) or in a different direction (hard). Consistent with Jiang and Chun (2001), T2-distractors impaired performance more during the AB relative to outside the AB. Critically, however, when the effect of T2-distractors was analyzed as a function of T1-load, the interference caused by T2 distractors was reduced when T1 was difficult relative to when T1 was easy. These results suggest that increasing T1-load decreases distractor processing during the AB and are congruent with studies demonstrating that the extent to which semantic information is processed during the AB depends on T1 task demands (Giesbrecht, Sy, & Elliott, 2007, Giesbrecht, Sy, & Lewis, 2008).