title: Global functional connectivity deficits in schizophrenia depend on behavioral state.
abstract: Schizophrenia is a devastating psychiatric illness characterized by deterioration of cognitive and emotional processing. It has been hypothesized that aberrant cortical connectivity is implicated in the disease (Friston, 1998), yet previous studies of functional connectivity (FC) in schizophrenia have shown mixed results (Garrity et al., 2007; Jafri et al., 2008; Lynall et al., 2010). We measured FC using fMRI in human schizophrenia patients and healthy controls during two different tasks and a rest condition, and constructed a voxel-based global FC index. We found a striking FC decrease in patients compared with controls. In the task conditions, relatively weaker FC was specific to regions of cortex not active during the task. In the rest condition, the FC difference between patients and controls was larger and allowed a case-by-case separation between individuals of the two groups. The results suggest that the relative reduction of FC in schizophrenia is dependent on the state of cortical activity, with voxels not activated by the task showing higher levels of FC deficiency. This novel finding may shed light on previous reports of FC in schizophrenia. Whether this neural characteristic is related to the development of the disorder remains to be established.
authors: Functional Brain Imaging Center, Wohl Institute for Advanced Imaging, Sourasky Medical Center, Tel Aviv 64239, Israel.
authors: Roy
authors: R
authors: Salomon
authors: Maya
authors: M
authors: Bleich-Cohen
authors: Avital
authors: A
authors: Hahamy-Dubossarsky
authors: Ilan
authors: I
authors: Dinstien
authors: Ronit
authors: R
authors: Weizman
authors: Michael
authors: M
authors: Poyurovsky
authors: Marina
authors: M
authors: Kupchik
authors: Moshe
authors: M
authors: Kotler
authors: Talma
authors: T
authors: Hendler
authors: Rafael
authors: R
authors: Malach
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000473:pathology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D012559:Schizophrenia / Q000473:pathology*; D012565:Schizophrenic Psychology; D014705:Verbal Behavior