It has been well-established that sustained attention and executive functioning are core deficits in schizophrenia (SZ). Growing evidence suggests that such attentional impairments may reflect disruptions in dominant intrinsic networks (INs). Functional network connectivity (FNC), described as the dependency between multiple INs, has revealed dysfunction among key INs in people with SZ. The objective of the current study was to test the hypothesis that SCZ would exhibit less specialized cognitive processing and therefore decreased FNC between dominant INs, and that any disruptions in FNC would predict neuropsychological profiles of attention. Methods: Thirty-five patients with SZ and thirty-three healthy controls (HC) were recruited for this study. Five minutes of eyes-closed resting-state fMRI (3T Trio scanner) was obtained for each participant. Resting-state scans were decomposed into 75 components using a group ICA suite (GIFT), and the FNC between all pair-wise components were obtained for each subject using the FNC toolbox. Participants were assessed using the Conners CPT II and the Wisconsin-card sorting task (WCST). Results: As expected, patients performed worse than HC on both tests of attention, and exhibited decreased FNC between default-mode subcomponents, a 'salience' (anterior cingulate and bilateral insulae) IN and basal ganglia IN; also, patients displayed increased FNC between a subcomponent of the DMN (anterior cingulate and bilateral middle frontal gyrus) and a frontal pole IN. Regression analyses showed that the aberrant FNC between specific component pairs predicted hit reaction time and clinical index scores on the CPT II and perseveration errors on the WCST. Conclusions: The current study highlights the importance of examining the organization of large-scale FNC between dominant INs to investigate attentional dysfunction in SZ. These results particularly highlight the importance of differentiating the subcomponents of the DMN in discriminating between HC and SZ. Future work should continue to address the role of these particular INs as they relate to cognitive ability and clinical symptoms in SZ, with the aim of establishing treatment interventions to improve, or 'normalize' the abnormal intrinsic functional connectivity observed in SZ.
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This work was supported by NIMH grant 2RO1 MH65304 and VA Merit Grant CSR&D:II-04-212-3 to Dr. Jose Canive, and a National Academies Ford Fellowship awarded to Michael Hunter.
Functional connectivity; executive and sustained attention; schziophrenia; basal ganglia; salience network
Hunter, Michael. "Large-scale intrinsic functional connectivity and attention in schizophrenia." (2013). https://digitalrepository.unm.edu/psy_etds/65