title: Altered balance of functional brain networks in Schizophrenia.
abstract: Activity in dorsal attention (DAN) and frontoparietal (FPN) functional brain networks is linked to allocation of attention to external stimuli, and activity in the default-mode network (DMN) is linked to allocation of attention to internal representations. Tasks requiring attention to external stimuli shift activity to the DAN/FPN and away from the DMN, and optimal task performance depends on balancing DAN/FPN against DMN activity. The current functional magnetic resonance imaging (fMRI) study assessed the balance of DAN/FPN and DMN activity in 13 schizophrenia patients and 13 healthy controls while they were engaged in a task switching Stroop paradigm which demanded internally directed attention to task instructions. The typical pattern of reciprocity between the DAN/FPN and DMN was observed for healthy controls but not for patients, suggesting a reduction in the internally focussed thought important for maintenance of instructions and strategies in schizophrenia. The observed alteration in the balance between DAN/FPN and DMN in patients may reflect a general mechanism underlying multiple forms of cognitive impairment in schizophrenia, including global processing deficits such as cognitive inefficiency and impaired context processing.
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada. Electronic address: todd.woodward@ubc.ca.
authors.forename: Todd S
authors.initials: TS
authors.lastname: Woodward
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
authors.forename: KaWai
authors.initials: K
authors.lastname: Leong
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada.
authors.forename: Nicole
authors.initials: N
authors.lastname: Sanford
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Tipper
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada.
authors.forename: Katie M
authors.initials: KM
authors.lastname: Lavigne
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009415:Nerve Net / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*; D057190:Stroop Test
keywords: Functional connectivity; Functional magnetic resonance imaging; Stroop stimuli; Task switching