Abstract
Visual search for a unique target is impaired when a task-irrelevant salient distractor is simultaneously present. This phenomenon, known as attentional capture, is said to occur because attention is diverted to a distractor in a stimulus-driven way before it reaches the target (Theeuwes, 1992). However, another view holds that attention could be directed selectively to a task-relevant feature under an appropriate attentional set (Folk et al., 2002). Recently, Ghorashi et al. (2003) suggested that temporal attentional capture (Folk et al., 2002) represents virtually the same impairment as that observed in the attentional blink. The question is whether these phenomena emerge from a common underlying attentional mechanism. The present study examined this question using correlation studies. If these phenomena share a common foundation, the magnitude of these deficits should show within-subject correlations. In Experiment 1, 135 participants performed three tasks in a counter-balanced order. The tasks for spatial and temporal capture and the attentional blink were identical to those used by Theeuwes (1992), Folk et al. (2002) and Chun and Potter (1995), respectively. A significant attentional deficit was observed in each task. However, no significant correlation was found across these tasks, suggesting that these deficits reflect different aspects of selective attention. In Experiment 2 (N=95), identical results were obtained using the same procedure as that in Experiment 1 except that another attentional blink task, requiring spatial switching between the two targets, was included. Strong correlations emerged only between the two attentional blink tasks (with/without spatial switch). The present results suggest that the attentional capture revealed by the two types of procedures (Theeuwes' and Folk's) reflects different aspects of attention. The results also indicate that the similarity between attentional capture and attentional blink is superficial.