Orienting reaction habituation in chronic alcoholics.

A polygraphic study on resistance to habituation of the somatic (EMG), autonomic (finger plethysmogram, galvanic skin reaction, respiration) and EEG (acoustic-evoked potential and EEG-blocking reaction) components of the orienting reaction elicited by a repetitive auditory stimulus was performed in 67 chronic alcoholics and in 70 matched normal subjects (control group). The study showed a significantly lower resistance to habituation of the orienting reaction in alcoholics than in normal control subjects. The severity of this habituation disturbance depended on the patients' age, type of alcoholism, alcohol consumption intensity and chronicity, as well as the type of resting EEG.