For prolonged cognitive tasks the efficiency of an observer, as a function of test period, is often illustrated as a downward-sloping curve. This deterioration is called the vigilance decrement and is due to a shift in attention during a task. We have investigated the temporal features of attention by using an RSVP task. We focused on transient performance in a trial, in addition to prolonged performance throughout the experiment. Throughout the experiment a vigilance decrement occurred. During a trial however, the detection of a target at the beginning of a sequence was dramatically low and recovered as it appeared later. This result has been shown neither in the vigilance studies, which predict high performance after the task onset, nor in the RSVP studies, which predict high and fair detection of only target in the sequence. This result would reflect a gradual modulation of temporal attention to a rapid sequence.

Summary of Awarded Presentation at the 23rd Annual Meeting