BackgroundImpaired cognitive control has been linked to weakened self-regulatory processes underlying compulsive substance intake. Previous research has provided evidence for impaired task performance in substance-abusing groups during Stroop and Go/No-Go tasks. Mechanisms of distractor suppression in visual search might also involve overlapping regulatory components that support goal-directed behavior by resolving the attentional competition between distractors and the target of search. However, the efficiency of learning-dependent distractor suppression has not been examined in the context of drug abuse and a direct comparison between cognitive control and distractor suppression is lacking. MethodA total of 84 participants were assigned either to the heavy drinking group (ALC, n = 42) or the control group (CTL, n = 42) based on self-reported substance use. Participants completed the Alcohol Use Disorders Identification Test (AUDIT) and Barratt Impulsiveness Scale (BIS). After that, participants completed a computerized version of the Stroop task, Go/No-go task, and a visual search task measuring learning-dependent distractor suppression. ResultsThe Stroop effect and the frequency of no-go errors did not differ between groups. However, learned distractor suppression was significantly blunted in the ALC group compared to the control group. Across participants, performance on the Stroop and Go/No-go task were correlated, while the magnitude of distractor suppression was related to neither. ConclusionsOur findings support a divergence of mechanistic processes underlying cognitive control and attentional control, and demonstrate impaired learning-dependent distractor suppression in heavy drinkers relative to a control group. Impaired distractor suppression offers new insight into why drug cues can be difficult to ignore.
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