Fixation time is a sensitive measure of cocaine cue attentional bias

Background and aims: Attentional bias has been demonstrated to a variety of substances. Evidence suggests that fixation time is a more direct measure of attentional bias than response time. The aims of this experiment were to demonstrate that fixation time during the visual probe task is a sensitive and stable measure of cocaine cue attentional bias in cocaine-using adults compared to controls.

Design: A between-subject, repeated-measures experiment.

Setting: An out-patient research unit.

Participants: Fifteen cocaine using and 15 non-cocaine-using adults recruited from the community.

Measurements: Participants completed a visual probe task with eye tracking and a modified Stroop during two experimental sessions.

Findings: A significant interaction between cue type and group (F = 13.5; P < 0.05) indicated that cocaine users, but not controls, displayed an attentional bias to cocaine-related images as measured by fixation time. There were no changes in the magnitude of attentional bias across sessions (F = 3.4; P > 0.05) and attentional bias correlated with self-reported life-time cocaine use (r = 0.64, P < 0.05). Response time on the visual probe (F = 1.1; P > 0.05) as well as on the modified Stroop (F = 0.1; P > 0.05) failed to detect an attentional bias.

Conclusions: Fixation time on cocaine-related stimuli (propensity to remain focused on the stimulus) is a sensitive and stable measure of cocaine cue attentional bias in cocaine-using adults.