Temporal allocation of visual attention in adult attention deficit hyperactivity disorder.

In two experiments, we examined the ability of adults with attention deficit hyperactivity disorder (ADHD) to process multiple targets appearing in a rapid serial visual presentation (RSVP) stream. Using a standard attentional blink (AB) task, subjects were required to both identify a target in the RSVP stream and detect a probe appearing in one of several posttarget serial positions. In Experiment 1, ADHD adults exhibited a protracted AB compared to controls, in that their probe detection did not improve as a function of increasing probe-to-target intervals (450-720 msec). In Experiment 2, the ADHD group performed as well as controls in detecting probes appearing immediately (i.e., 90 msec) after the target. Taken together, the results demonstrate that adults with ADHD exhibit a selective deficit in rapidly shifting attention between the target and the probe, when the two appear several hundred milliseconds apart. These results suggest that adults with ADHD can use automatic (reflexive) attention to detect items in close temporal proximity in the RSVP stream, but have difficulty allocating controlled attention to multiple stimuli separated by several hundred milliseconds.