title: Prefrontal cortex connectivity dysfunction in performing the Fist-Edge-Palm task in patients with first-episode schizophrenia and non-psychotic first-degree relatives.
abstract: Neurological soft signs have been considered one of the promising neurological endophenotypes for schizophrenia. However, most previous studies have employed clinical rating data only. The present study aimed to examine the neurobiological basis of one of the typical motor coordination signs, the Fist-Edge-Palm (FEP) task, in patients with first-episode schizophrenia and their non-psychotic first degree relatives. Thirteen patients with first-episode schizophrenia, 14 non-psychotic first-degree relatives and 14 healthy controls were recruited. All of them were instructed to perform the FEP task in a 3 T GE Machine. Psychophysiological interaction (PPI) analysis was used to evaluate the functional connectivity between the sensorimotor cortex and frontal regions when participants performed the FEP task compared to simple motor tasks. In the contrast of palm-tapping (PT) vs. rest, activation of the left frontal-parietal region was lowest in the schizophrenia group, intermediate in the relative group and highest in the healthy control group. In the contrast of FEP vs. PT, patients with schizophrenia did not show areas of significant activation, while relatives and healthy controls showed significant activation of the left middle frontal gyrus. Moreover, with the increase in task complexity, significant functional connectivity was observed between the sensorimotor cortex and the right frontal gyrus in healthy controls but not in patients with first episode schizophrenia. These findings suggest that activity of the left frontal-parietal and frontal regions may be neurofunctional correlates of neurological soft signs, which in turn may be a potential endophenotype of schizophrenia. Moreover, the right frontal gyrus may play a specific role in the execution of the FEP task in schizophrenia spectrum disorders.
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Raymond C K
authors.initials: RC
authors.lastname: Chan
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Applied Psychology and Behavioral Basis of Health Program, Griffith Health Institute, Griffith University, Brisbane, Australia.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Radiology Department, Peking University People's Hospital, Peking, China.
authors.forename: Yun-yao
authors.initials: YY
authors.lastname: Lai
authors.affiliation: Radiology Department, Peking University People's Hospital, Peking, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Hong
authors.affiliation: School of Applied Psychology and Behavioral Basis of Health Program, Griffith Health Institute, Griffith University, Brisbane, Australia ; Menzies Health Institute Queensland and School of Applied Psychology, Griffith University, Gold Coast, Australia.
authors.forename: David H K
authors.initials: DH
authors.lastname: Shum
authors.affiliation: Castle Peak Hospital, Hong Kong, China.
authors.forename: Eric F C
authors.initials: EF
authors.lastname: Cheung
authors.affiliation: Peking University Sixth Hospital, Beijing, China ; Peking University Institute of Mental Health, Beijing, China ; Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
authors.affiliation: Institute of Psychiatry, King's College London, London, UK ; National Institute for Health Research (NIHR), Mental Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust, King's College London, London, UK.
authors.forename: Paola
authors.initials: P
authors.lastname: Dazzan
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005190:Family; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009434:Neural Pathways / Q000503:physiopathology; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011597:Psychomotor Performance; D012559:Schizophrenia / Q000503:physiopathology*; D066191:Sensorimotor Cortex / Q000503:physiopathology*; D055815:Young Adult
keywords: Endophenotype; First degree relatives; First episode schizophrenia; Neurological soft sign