Direct evidence of inter-target response competition for limited resources in attentional blink.

In everyday life, we sometimes fail to notice a second event if it follows too closely after another-this phenomenon, known as the attentional blink (AB), reveals inherent limits in our ability to process rapid streams of information. The AB is characterized by an impairment in accurately identifying a second target (T2), presented after a first target (T1) within a 200-500 ms window amid a rapid sequence of distractors. It has been widely theorized that the AB results from constraints on late-stage processing. Building on the classic AB paradigm, we manipulated response congruency between T1 and T2 to examine whether the response selection of T2 is constrained during the AB period. We recruited 31 participants and recorded electroencephalography (EEG) data throughout the experiment. The results indicated that congruent responses between the targets significantly improved T1 and T2 accuracy and attenuated the AB magnitude. EEG analysis revealed that incongruent responses, as opposed to congruent ones, led to different patterns in the late stage of T2 processing and were associated with larger P3b amplitudes for T2 recognition. Multivariate pattern analysis also showed the response congruency could be distinguished during the late stage of T2 processing. Notably, these effects were specifically observed within the AB time window and were absent outside this interval. These results suggest that targets vie for the limited late-stage processing resources during the AB period. However, congruence in responses among targets reduces this competitive demand, thereby mitigating the effects of the AB.