Cocaine-related stimuli impair inhibitory control in cocaine users following short stimulus onset asynchronies

Background and Aims: Cocaine users display a significant increase in inhibitory failures following cocaine-related images compared with neutral images in a modified cued Go/No-Go task, the Attentional Bias-Behavioral Activation (ABBA) task. The aim of this study was to demonstrate that stimulus onset asynchrony (SOA) impacts inhibitory failures on the ABBA task. Design: A between-subjects experiment. Setting: An out-patient research unit in the United States. Participants: Ninety-one cocaine users recruited from the community. Measurements: Participants were assigned to groups in which they saw either cocaine (n=46) or neutral (n=45) images as the go condition. Cues were presented for one of five SOAs (i.e. 100, 200, 300, 400 or 500ms) before a go or no-go target was displayed. Findings: Participants in the cocaine go condition had a significantly higher proportion of inhibitory failures to no-go targets (F_4,356=2.50, P=0.04) with significantly more inhibitory failures following all SOAs (P<0.05) than those in the neutral go condition. Within the cocaine go condition, significantly more inhibitory failures were observed following the 100 and 200ms SOAs than after the 300, 400 or 500ms SOAs (P<0.05). Conclusions: Cocaine-related stimuli appear to decrease inhibitory control in cocaine users at short (100 and 200ms) stimulus onset asynchronies (SOAs: the amount of time between the start of one stimulus and the start of another stimulus), but not at longer (300, 400 and 500ms) SOAs.