Several previous studies have examined the DMN in schizophrenia. Two studies measuring the temporal homogeneity of BOLD signal reported reductions in coherence of activity in the cerebral cortex and cerebellum (Liang et al., 2006; Liu et al., 2006). These studies used region-of-interest based analyses and cannot be compared with the current work. Another study using a functional connectivity approach examined the DMN in schizophrenia, and reported reduced connectivity among dorsomedial PFC, parietal, and temporal regions of the DMN, which was interpreted as “functional disintegration” (Zhou et al., 2007). Reduced integration of brain activity across areas was also reported by a study of the dorsolateral PFC and striatum (Salvador et al., 2007), and by a study of posterior cingulate cortex connectivity with prefrontal, temporal, and parietal cortex and the cerebellum (Bluhm et al., 2007). Finally, another study used ICA to study outpatients with schizophrenia during a simple auditory oddball task (Garrity et al., 2007). In that study, unlike in ours, ventromedial PFC and anterior cingulate cortex were more coherent with the DMN in schizophrenia than in control subjects. There are many
