An attentional blink in the absence of spatial attention: a cost of awareness?

The attentional blink refers to the finding that when two visual targets appear within 200–500 ms, observers often miss the second target. In three experiments, we disentangle the roles of spatial attention to and conscious report of the first event in eliciting this cost. We show that allocating spatial attention to the first event is not necessary for a blink to occur: the full temporal pattern of the blink arises when the first event is consciously detected, despite the fact that it is not spatially attended, whereas no cost is observed when the first event is missed. We then show that spatial attention is also not sufficient for eliciting a blink, though it can deepen the blink when accompanied by conscious detection. These results demonstrate that there is no cost associated with the initiation of an attentional episode, whereas explicit conscious detection comes at a price. These findings demonstrate the temporal flexibility of attention and underscore the potential role of subjective awareness in understanding processing limitations, although this role may be contingent on the encoding in working memory necessary for conscious report.