As predicted, nonalcoholics exhibited significantly larger P3 amplitudes to the 90-degree target than to the 3-degree target. Alcoholic subjects did not exhibit significant differences in P3 amplitude between easy and difficult targets or between targets and nontargets. This indicates that alcoholic subjects find the discrimination task more difficult and are more uncertain of their responses. In addition, alcoholic subjects tend to stress speed over accuracy in some cognitive tasks. In the above study, alcoholics exhibited faster reaction times3 and made more errors than nonalcoholic subjects. This suggests that alcoholics may respond to stimuli without fully evaluating them (for review, see Porjesz and Begleiter 1993).
