[Effect of alcohol on interhemispheric functional relations].

By means of backward masking, the time of perception of letter stimuli presented to the left and right visual fields, was determined in practically healthy persons who were given different doses of alcohol, and in patients with chronic alcoholism. Evoked electrical activity to the same stimuli was recorded in identical conditions. A small dose of alcohol (0.41 g/kg) increases in healthy subjects the time of perception of visual signals only if they are presented in the left visual field: a medium dose (0.82 g/kg) increases the time of stimuli perception in both halves of the visual field, but obviously more so in the left one, in patients with chronic alcoholism the time of perception is substantially longer in the left visual field. A small dose of alcohol does not affect evoked electrical cortical activity in healthy persons. Distinct regional differences are exhibited in the action of the medium dose of alcohol on the cerebral cortex of healthy persons. Evoked potential in the central area is depressed to a greater extent than in the visual and associative (Brodman field 37) zones. With chronic alcohol intoxication, evoked activity in the right hemisphere is depressed considerably more than in the left one.