PREPULSE INHIBITION OF THE STARTLE EYEBLINK AS AN INDICATOR OF TEMPORAL SUMMATION

The inhibition of the human startle eyeblink response was assessed in three experiments in which the duration of the prepulse was manipulate d. In all cases, inhibition of startle was more pronounced as prepulse duration increased from 6 to 50 msec. Inhibition of startle amplitude for single prepulses was not significantly different from that for pa ired prepulses (Experiment 1), but inhibition was more pronounced as p repulse intensity increased (Experiment 3). Varying the interval betwe en prepulse offset acid startle-stimulus onset had no significant effe ct on inhibition (Experiment 2). These data demonstrate the sensitivit y of startle inhibition to prepulse duration, and suggest that this re sponse system can be used to evaluate early temporal summation in the auditory system.