Abstract
When two targets (T1, T2) are inserted in a rapid stream of distractors, perception of T2 is impaired at short inter-target lags, a phenomenon known as the Attentional Blink. Identification accuracy for T2 is sometimes spared if T2 is presented directly after T1 (Lag-1 sparing). Research typically shows that Lag-1 sparing occurs only if the two targets appear in the same spatial location. It has recently been suggested, however, that the spatial relationship between the targets is not the determining factor; rather, Lag-1 sparing occurs whenever T2 appears within the focus of attention (Jefferies, Ghorashi, Kawahara, & Di Lollo, 2007; Jefferies & Di Lollo, 2009). According to this hypothesis, if the focus of attention shifts from the location of T1 to a second location, not only should Lag-1 sparing occur to T2 if it appears at the newly-attended location (Jefferies & Di Lollo, 2009), but Lag-1 sparing should comparably not occur to T2 at the now-unattended T1 location. The second half of this hypothesis – as yet unverified – is tested here by combining an attentional blink paradigm with a peripheral contingent capture paradigm. In Experiment 1, we found that when attention is shifted to a peripheral, task-relevant distractor, Lag-1 sparing occurred if T2 appeared at the newly-attended peripheral location, but not if it appeared at the central stream (i.e., the now-unattended location of T1). In Experiment 2, we found that if insufficient time is allowed for an attention shift to be completed, the focus of attention remains at the T1-location, and Lag-1 sparing is again found if T2 appears in the same location as T1. In summary, the current research tests and confirms the hypothesis that the critical determinant of Lag-1 sparing is T2 occurring within the focus of attention, not the targets appearing in the same spatial location.
Natural Sciences and Engineering Research Council of Canada.