title: Hyper-coupling between working memory task-evoked activations and amplitude of spontaneous fluctuations in first-episode schizophrenia.
abstract: Working memory (WM) deficit is an important component of impaired cognition in schizophrenia. However, between-studies inconsistencies as to the specific functional substrate imply that inter-individual variability (IIV) in the WM performance is associated with IIV in brain activity in schizophrenia. To examine the neural substrate of this WM IIV, we studied whether the neural mechanisms that underlie individual differences in WM capacity are the same in schizophrenia patients and healthy people. We correlated the IIV of the task-evoked brain activity and task performance during an n-back WM task with the IIV of the moment-to-moment variability in intrinsic resting-state activity, as measured by the amplitude of low-frequency fluctuations (ALFFs) and further compared this relationship between 17 patients with first-episode schizophrenia (FES) and 18 healthy controls. Between-group comparisons of the correlation patterns indicated aberrant ALFF-WM activation correlations and ALFF-WM performance correlations in the FES patients, but no significant changes were detected in any single measurement of these three characteristics. Specifically, we found increased positive ALFF-WM activation correlations in the bilateral lateral prefrontal cortices, posterior parietal cortices and fusiform gyri in the FES patients. We also observed significant increases in positive ALFF-WM performance correlations in the bilateral ventromedial prefrontal cortices in the FES patients. This hyper-coupling between the ALFF and fMRI measures during a WM task may indicate that it was difficult for the patients to detach themselves from one state to transition to another and suggests that the inefficient cortical function in schizophrenia stems from the intrinsic functional architecture of the brain.
authors.affiliation: Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xi-Nian
authors.initials: XN
authors.lastname: Zuo
authors.affiliation: Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Huiran
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China; National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Tianzi
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China. Electronic address: zningl@163.com.
authors.forename: Zhening
authors.initials: Z
authors.lastname: Liu
mesh_terms: D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: Amplitude of low-frequency fluctuation; Brain–behavior association; First-episode schizophrenia; Prefrontal cortex; Task-evoked activity; Working memory