Two attentional deficits in serial target search: The visual attentional blink and an amodal task-switch deficit.

When monitoring a rapid serial visual presentation at 100 ms per item for 2 targets among distractors, viewers have difficulty reporting the 2nd target (T2) when it appears 200-500 ms after the onset of the 1st letter target (T1): an attentional blink (AB; M. M. Chun & M. C. Potter, 1995b; J. E. Raymond, K. L. Shapiro, & K. M. Arnell, 1992). Does the same deficit occur with auditory search? The authors compared search for auditory, visual, and cross-modal targets in 2 tasks: (a) identifying 2 target letters among digits (Experiments 1-3 and 5) or digits among letters (Experiment 6), and (b) identifying 1 digit among letters and deciding whether an X occurred among the subsequent letters (Experiment 4). In the experiments using the 1st task, the standard AB was found only when both targets were visual. In the 2nd task, with a change in selective set from T1 to T2, a task-switching deficit was obtained regardless of target modality.