Working Memory Modulation of Frontoparietal Network Connectivity in First-Episode Schizophrenia.
Working memory (WM) impairment is regarded as a core aspect of schizophrenia. However, the neural mechanisms behind this cognitive deficit remain unclear. The connectivity of a frontoparietal network is known to be important for subserving WM. Using functional magnetic resonance imaging, the current study investigated whether WM-dependent modulation of effective connectivity in this network is affected in a group of first-episode schizophrenia (FES) patients compared with similarly performing healthy participants during a verbal n-back task. Dynamic causal modeling (DCM) of the coupling between regions (left inferior frontal gyrus (IFG), left inferior parietal lobe (IPL), and primary visual area) identified in a psychophysiological interaction (PPI) analysis was performed to characterize effective connectivity during the n-back task. The PPI analysis revealed that the connectivity between the left IFG and left IPL was modulated by WM and that this modulation was reduced in FES patients. The subsequent DCM analysis confirmed this modulation by WM and found evidence that FES patients had reduced forward connectivity from IPL to IFG. These findings provide evidence for impaired WM modulation of frontoparietal effective connectivity in the early phase of schizophrenia, even with intact WM performance, suggesting a failure of context-sensitive coupling in the schizophrenic brain.
CAS Key Laboratory of Behavioral Science, Institute of Psychology, Beijing, PR China.|Sino-Danish Center for Education and Research, Aarhus, Denmark.|Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark.
Jesper Duemose
JD
Nielsen
Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark.|Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark.
Kristoffer H
KH
Madsen
Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, PR China.
Zheng
Z
Wang
Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, PR China.
Zhening
Z
Liu
Wellcome Trust Centre for Neuroimaging, University College London, London, UK.
Karl J
KJ
Friston
CAS Key Laboratory of Behavioral Science, Institute of Psychology, Beijing, PR China.|Wellcome Trust Centre for Neuroimaging, University College London, London, UK.|Department of Psychology, University of Chinese Academy of Sciences, Beijing, PR China.
Yuan
Y
Zhou
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D008570:Memory, Short-Term; D008959:Models, Neurological; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D017711:Nonlinear Dynamics; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*; D012559:Schizophrenia / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology*; D012565:Schizophrenic Psychology; D055815:Young Adult
dynamic causal modeling; dysconnection hypothesis; functional magnetic resonance imaging; n-back