Attentional control and capture in the attentional blink paradigm: Evidence from human electrophysiology

We studied attentional control mechanisms using electrophysiological methods, focusing on the N2pc event-related potential (ERP), to track the moment-bymoment deployment of visual spatial attention. Two digits (T-1 and T-2, both red or both green, and masked, were embedded in a rapid serial visual presentation of letter distractors with an SOA of 200 ms or 800 ms. T-1 was at fixation, whereas T-2 was 3 degrees to the left or right of fixation and presented with a concurrent equiluminant distractor digit in a different colour. T-1 and T-2 were reported in one block of trials, and only T-2 in another block (order counterbalanced). Accuracy for T-2 was lower at short SOA than at long SOA when both T-1 and T-2 were reported, suggesting an attentional blink (AB) effect. It was difficult to ignore T-1 because T-1 had the same colour as T-2, producing a large deficit in T-2 accuracy at short SOA in the control condition. The amplitude of the N2pc ERP component was attenuated in the short-SOA condition relative to the long-SOA condition, both in the experimental and the control conditions, suggesting that T-1 involuntarily captured visual spatial attention and that while attention was deployed on T-1, the processing of T-2 was significantly impaired.