title: Neural correlates of covert face processing: fMRI evidence from a prosopagnosic patient.
abstract: Brains can perceive or recognize a face even though we are subjectively unaware of the existence of that face. However, the exact neural correlates of such covert face processing remain unknown. Here, we compared the fMRI activities between a prosopagnosic patient and normal controls when they saw famous and unfamiliar faces. When compared with objects, the patient showed greater activation to famous faces in the fusiform face area (FFA) though he could not overtly recognize those faces. In contrast, the controls showed greater activation to both famous and unfamiliar faces in the FFA. Compared with unfamiliar faces, famous faces activated the controls', but not the patient's lateral prefrontal cortex (LPFC) known to be involved in familiar face recognition. In contrast, the patient showed greater activation in the bilateral medial frontal gyrus (MeFG). Functional connectivity analyses revealed that the patient's right middle fusiform gyrus (FG) showed enhanced connectivity to the MeFG, whereas the controls' middle FG showed enhanced connectivity to the LPFC. These findings suggest that the FFA may be involved in both covert and overt face recognition. The patient's impairment in overt face recognition may be due to the absence of the coupling between the right FG and the LPFC.
authors: School of Computer and Information Technology, Beijing Jiaotong University, Beijing100044, China.
authors: Jiangang
authors: J
authors: Liu
authors: Henan Provincial People's Hospital, Zhengzhou 450003, China.
authors: Meiyun
authors: M
authors: Wang
authors: Henan Provincial People's Hospital, Zhengzhou 450003, China.
authors: Xiaohong
authors: X
authors: Shi
authors: Institute of Automation Chinese Academy of Sciences, Beijing 100190, China.
authors: Lu
authors: L
authors: Feng
authors: School of Computer and Information Technology, Beijing Jiaotong University, Beijing100044, China.
authors: Ling
authors: L
authors: Li
authors: Dr. Eric Jackman Institute of Child Study, University of Toronto, Toronto M5R 2X2, Canada.
authors: Justine Marie
authors: JM
authors: Thacker
authors: Institute of Automation Chinese Academy of Sciences, Beijing 100190, China School of Life Sciences and Technology, Xidian University, Xi'an 710071, China tian@ieee.org cjr.shidapeng@vip.163.com kang.lee@utoronto.ca.
authors: Jie
authors: J
authors: Tian
authors: Henan Provincial People's Hospital, Zhengzhou 450003, China.
authors: Dapeng
authors: D
authors: Shi
authors: Dr. Eric Jackman Institute of Child Study, University of Toronto, Toronto M5R 2X2, Canada.
authors: Kang
authors: K
authors: Lee
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001929:Brain Edema / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D004192:Discrimination, Psychological / Q000502:physiology; D005145:Face; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017237:Mitochondrial Encephalomyopathies / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D020238:Prosopagnosia / Q000473:pathology / Q000503:physiopathology*; D011601:Psychophysics; D014796:Visual Perception / Q000502:physiology*
keywords: covert recognition; fMRI; face processing; fusiform gyrus; prosopagnosia