Variability of Facilitation and Inhibition as a Function of Cue Validity and Cue-Stimulus Intervals in the Orienting of Sustained Attention

45 subjects performed a cued vigilance task in which location cues were presented at intervals of 150, 350, or 550 msec. before the display of the stimulus, that is, three cue-stimulus intervals. Targets preceded by valid location cues led to a normal decrement in vigilance over time, whereas targets preceded by invalid location cues produced an increment in sensitivity (d'). The results suggested that under certain conditions shifts of attention may enhance vigilance.