Visual evoked response and alcohol intoxication.

Twelve eye healthy test persons were followed for 2 h after alcohol intake by frequent recordings of visually evoked pattern responses (VER's) and simultaneous determinations of the blood alcohol concentrations. VER's were recorded with a stimulus of 14' and 110' check size, and for both check sizes steady state (15 shifts per sec) and transient responses (2 shifts per sec) were analyzed. In the transient responses we found a general increase in latencies after alcohol intake, but only in one stimulus modality (2 shifts per sec, 14' check size) was the deviation statistically significant. The steady state responses showed a large pre-alcoholic variability both in amplitudes and in latencies. No change was discernible after alcohol intake. No correlation was found between the various levels of alcohol concentration and any of the VER parameters. The minor changes of the VER found in this study using a patterned stimulus are discussed and compared to the findings in earlier studies using a flash as well as a patterned stimulus.