In the visual line discrimination task, nonalcoholic subjects manifested significantly earlier P3 latencies to easy discriminations compared with difficult discriminations. In alcoholics, P3 latency was delayed for the easy targets, such that P3 latency was comparable for both easy and difficult targets. These results suggest that alcoholics found both discriminations difficult and adopted an undifferentiated mode of responding regardless of task requirements (for review, see Porjesz and Begleiter 1993).
