Dynamics of a Stroop matching task: effect of alcohol and reversal with training

Using a Stroop matching task, we evaluated how alcohol affects the time needed to overcome Stroop conflict and whether practice might reverse the effect of alcohol. Participants (n = 16) performed two sessions in which they had to compare the color of a color-word with the meaning of a color-word in neutral color. The two task stimuli were presented simultaneously or with a Stimulus Onset Asynchrony (SOA) of 200, 500, or 800 ms. For half of the subjects, alcohol was administered in the first session, and for the other half, alcohol was administered in the second session. The results showed that the Stroop effect was significant at the 0 and 200 ms intervals in the sober subjects. Moreover, in untrained intoxicated individuals, interference endured until the 500 ms interval, a result that was abolished in trained intoxicated subjects. In conclusion, alcohol increased the time needed for Stroop matching task conflict resolution. However, this deleterious effect was minimized by a previous practice session.