To determine the frequency with which cue-induced craving studies observed visual cortex activity to drug cues, these 55 articles were thoroughly examined, noting information from all tables and figures, sample size, characteristics of the subject population, cue-exposure paradigm, analytic approach, statistical thresholding, the nature of the control condition/group, the cluster size, and the spatial location of visual cortex activity if it was observed. Of these 55 studies that performed a whole-brain voxel-based analysis of the BOLD response to visual cues of a drug in a substance-using group, 28 reported a detailed table of results describing regional brain activity elicited from a drug-cue versus neutral contrast in the substance-using group (Figure 1, Table 1, top).
