Effects of a startle stimulus on response speed and inhibition in a go/no-go task.

Two studies examined the interaction of an acoustic startle stimulus and visual go/no-go task stimuli on startle reactivity and task performance. In the first study, an acoustic stimulus (50 ms, 100 dB noise) was presented alone or with a green (go) or red (no-go) circle; in the second study, a prepulse (50 ms, 75 dB noise) was presented alone or 120 ms before the startle stimulus or circle. The startle stimulus speeded responses to the go stimuli and increased the covert false alarm rate in the no-go condition (measured by EMG activity in the hand), although very few overt errors were made in the no-go condition.