title: Aberrant intrinsic brain activity and cognitive deficit in first-episode treatment-naive patients with schizophrenia.
abstract: BACKGROUND
  Given the important role of the default mode network (DMN) in cognitive function and the well-known neurocognitive deficit in schizophrenia, it is intriguing to examine systematically the relationship between neurocognitive dysfunction and aberrant intrinsic activities, and also functional connectivity, of the DMN in patients with schizophrenia. Method First-episode, treatment-naive patients with schizophrenia (FES) (n = 115) and healthy controls (n = 113) underwent resting-state functional magnetic resonance imaging (fMRI) scans and neurocognitive tests. Intrinsic neural activities evaluated by using the fragment amplitude of low-frequency fluctuations (fALFF) and the resting-state functional connectivity assessed by seed-based correlational analysis were compared between patients and controls. Aberrant intrinsic activities and DMN connectivity in patients were then correlated to neurocognitive performance and clinical symptoms.
  
  
  RESULTS
  Compared to controls, patients with FES showed decreased fALFF in the bilateral medial prefrontal cortex (MPFC) and the orbitofrontal cortex (OFC), and increased fALFF in the bilateral putamen. Increased functional connectivity with the DMN was observed in the left insula and bilateral dorsolateral PFC (DLPFC) in patients with FES. In patients, aberrant fALFF in the bilateral OFC were correlated with cognitive processing speed; fALFF in the left OFC and right putamen were correlated with the clinical factors excited/activation and disorganization; and increased DMN functional connectivity in the left insula was correlated with the clinical factors positive, excited/activation, disorganization and neurocognitive deficit in the domain of sustained attention.
  
  
  CONCLUSIONS
  These associations between neurocognitive dysfunction and aberrant intrinsic activities, and also functional connectivity, of the DMN in patients with schizophrenia may provide important insights into the neural mechanism of the disease.
authors.affiliation: The Mental Health Center and the Psychiatric Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Z
authors.initials: Z
authors.lastname: He
authors.forename: W
authors.initials: W
authors.lastname: Deng
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Jiang
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Huang
authors.forename: D A
authors.initials: DA
authors.lastname: Collier
authors.forename: Q
authors.initials: Q
authors.lastname: Gong
authors.forename: X
authors.initials: X
authors.lastname: Ma
authors.forename: N
authors.initials: N
authors.lastname: Zhang
authors.forename: T
authors.initials: T
authors.lastname: Li
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007406:Interview, Psychological; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012146:Rest / Q000502:physiology; D012559:Schizophrenia / Q000150:complications / Q000503:physiopathology*; D012565:Schizophrenic Psychology