There is a strong interest in using attentional bias to drug cues as a biomarker for addiction. The collection of human functional neuroimaging studies examined in this manuscript demonstrate with remarkable consistency that substance-dependent individuals have significantly higher activity in the primary and secondary visual cortices when exposed to a drug versus non-drug cue. Although visual gaze tracking is routinely performed in human functional neuroimaging studies, none of the studies included in this meta-analysis directly compared visual gaze tracking metrics to occipital cortex activity. Future research in this area will be able to directly test whether human laboratory metrics of attentional bias to drug cues, including fixation time, are directly related to visual cortex activity—which would suggest that visual cortex activity is a strong, consistent biomarker of addiction.
