Selective effects of alcohol on electrodermal indices of orienting reflexes to signal and nonsignal stimuli

Effects of a moderate dose of alcohol on the electrodermal orienting reflexes evoked by novel signal, novel nonsignal, and common nonsignal stimuli were assessed. Social drinkers were randomly assigned to the four cells of a balanced placebo design, with 10 males and 10 females per group. They drank a beverage consisting of either tonic water only, or tonic water plus enough vodka to raise blood alcohol levels to approximately .05%. Following drinking and absorption periods, spontaneous and evoked skin conductance responses (SCRs) were recorded. Subjects pressed a footpedal whenever they heard an odd stimulus tone in a series. Alcohol increased the frequency of spontaneous SCRs, increased the number of incorrect pedal‐press responses, and selectively enhanced SCRs evoked by the signal tone, p<.05. Results are interpreted in terms of a hypothesized selective effect of alcohol on frontal cortical inhibitory functions.