Opiate pharmacology and individual differences. II. Somatosensory evoked potentials

Abstract
Somatosensory evoked potentials (EPs) to stimuli ranging from barely perceptible to painful were recorded in 153 normal human adults. Reliability of amplitude and amplitude/intensity slopes were demonstrated in 29 individuals tested twice, 2 or more weeks apart. In randomized, double-blind placebo controlled trials, both aspirin and morphine significantly diminished the N120 component at high stimulus intensities. Age, sex and pharmacological effects paralleled those found with psychophysical techniques in part 1 of this study.