Identification of the second of two targets is impaired if it is presented less than about 500 ms after the first. Three models of this second-target deficit, known as attentional blink (AB), were compared:resource-depletion, bottleneck, and temporary loss of control (TLC). Five experiments, in which three sequential targets were inserted in a stream of distractors, showed that identification accuracy for the leading target depended on an attentional switch whose magnitude varied with distractor–target similarity. In contrast, accuracy for the trailing target depended on similarity between the target and the trailing mask. These results strongly suggest that the AB is not a unitary phenomenon. Resource-depletion was ruled out as a viable account. The effect of attentional switching was handled naturally by the TLC model, while bottleneck models offered the best account of the effect of backward masking.
