title: Impaired coupling of local and global functional feedbacks underlies abnormal synchronization and negative symptoms of schizophrenia.
abstract: BACKGROUND
  Abnormal synchronization of brain oscillations is found to be associated with various core symptoms of schizophrenia. However, the underlying mechanism of this association remains yet to be elucidated.
  
  
  RESULTS
  In this study, we found that coupled local and global feedback (CLGF) circuits in the cortical functional network are related to the abnormal synchronization and also correlated to the negative symptom of schizophrenia. Analysis of the magnetoencephalography data obtained from patients with chronic schizophrenia during rest revealed an increase in beta band synchronization and a reduction in gamma band power compared to healthy controls. Using a feedback identification method based on non-causal impulse responses, we constructed functional feedback networks and found that CLGF circuits were significantly reduced in schizophrenia. From computational analysis on the basis of the Wilson-Cowan model, we unraveled that the CLGF circuits are critically involved in the abnormal synchronization and the dynamical switching between beta and gamma bands power in schizophrenia. Moreover, we found that the abundance of CLGF circuits was negatively correlated with the development of negative symptoms of schizophrenia, suggesting that the negative symptom is closely related to the impairment of this circuit.
  
  
  CONCLUSIONS
  Our study implicates that patients with schizophrenia might have the impaired coupling of inter- and intra-regional functional feedbacks and that the CLGF circuit might serve as a critical bridge between abnormal synchronization and the negative symptoms of schizophrenia.
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Kyungchul
authors.initials: K
authors.lastname: Noh
authors.forename: Kyung Soon
authors.initials: KS
authors.lastname: Shin
authors.forename: Dongkwan
authors.initials: D
authors.lastname: Shin
authors.forename: Jae Yeon
authors.initials: JY
authors.lastname: Hwang
authors.forename: June Sic
authors.initials: JS
authors.lastname: Kim
authors.forename: Joon Hwan
authors.initials: JH
authors.lastname: Jang
authors.forename: Chun Kee
authors.initials: CK
authors.lastname: Chung
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
authors.forename: Kwang-Hyun
authors.initials: KH
authors.lastname: Cho
mesh_terms: D003198:Computer Simulation; D003344:Cortical Synchronization / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography; D008959:Models, Neurological; D056910:Republic of Korea; D012559:Schizophrenia / Q000503:physiopathology*; D013997:Time Factors