The magnitude of drug attentional bias is specific to substance use disorder

The visual probe task with eye tracking is a sensitive measure of cocaine and alcohol cue attentional bias. Despite the high comorbidity between cocaine and alcohol dependence, attentional bias studies have examined the influence of cocaine- and alcohol-related cues separately. The aim of this experiment was to directly compare the magnitude of cocaine and alcohol cue attentional bias in individuals dependent on cocaine or cocaine and alcohol. Individuals who met criteria for cocaine dependence (n = 20) or both cocaine and alcohol dependence (n = 20) completed a visual probe task with eye tracking. Cocaine-dependent participants displayed an attentional bias toward cocaine, but not alcohol. In contrast, cocaine-alcohol dependent participants displayed an attentional bias to both cocaine and alcohol, and the magnitude of these biases did not differ. The magnitude of cocaine cue attentional bias, however, was significantly smaller in the cocaine-alcohol dependent group compared to the cocaine-dependent group. These results suggest that fixation time during the visual probe task is sensitive to clinically relevant differences in substance use disorders. The incentive value of cocaine-related cues, however, may differ for individuals who are also dependent on alcohol.