Late auditory evoked potentials: a method for monitoring drug effects on the central nervous system

An auditory event-related potential paradigm was designed to objectively quantify the effects of drugs on the central nervous system (CNS). A series of tones was presented at three random interstimulus intervals (ISI). The amplitude of N1-P2 and the recovery of this complex across ISI appear to be rapid, reliable and sensitive measures of changes in brain function associated with drug intake. To illustrate, an acute dose of diazepam was administered orally to a small group of normal subjects. The amplitude of N1-P2 was reduced and the slope of recovery flattened, indicating a decrease in CNS excitability concomitantly with the established pharmacokinetics of the drug.