title: Handedness is related to neural mechanisms underlying hemispheric lateralization of face processing.
abstract: While the right-hemispheric lateralization of the face perception network is well established, recent evidence suggests that handedness affects the cerebral lateralization of face processing at the hierarchical level of the fusiform face area (FFA). However, the neural mechanisms underlying differential hemispheric lateralization of face perception in right- and left-handers are largely unknown. Using dynamic causal modeling (DCM) for fMRI, we aimed to unravel the putative processes that mediate handedness-related differences by investigating the effective connectivity in the bilateral core face perception network. Our results reveal an enhanced recruitment of the left FFA in left-handers compared to right-handers, as evidenced by more pronounced face-specific modulatory influences on both intra- and interhemispheric connections. As structural and physiological correlates of handedness-related differences in face processing, right- and left-handers varied with regard to their gray matter volume in the left fusiform gyrus and their pupil responses to face stimuli. Overall, these results describe how handedness is related to the lateralization of the core face perception network, and point to different neural mechanisms underlying face processing in right- and left-handers. In a wider context, this demonstrates the entanglement of structurally and functionally remote brain networks, suggesting a broader underlying process regulating brain lateralization.
authors.affiliation: Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich &ETH Zurich, CH-8032 Zurich, Switzerland.|Laboratory for Multimodal Neuroimaging (LMN), Department of Psychiatry, University of Marburg, D-35039 Marburg, Germany.|Department of Child- and Adolescent Psychiatry, University of Marburg, D-35039 Marburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Frässle
authors.affiliation: Social Neuroscience Lab | SNL, Department of Psychiatry and Psychotherapy, University of Lübeck, D-23538 Lübeck, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Krach
authors.affiliation: Social Neuroscience Lab | SNL, Department of Psychiatry and Psychotherapy, University of Lübeck, D-23538 Lübeck, Germany.
authors.forename: Frieder Michel
authors.initials: FM
authors.lastname: Paulus
authors.affiliation: Laboratory for Multimodal Neuroimaging (LMN), Department of Psychiatry, University of Marburg, D-35039 Marburg, Germany.|Core Facility Brainimaging, Department of Psychiatry, University of Marburg, D-35039 Marburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jansen
mesh_terms: D000328:Adult; D063132:Connectome; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000235:genetics*; D066128:Gray Matter / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008959:Models, Neurological; D011680:Pupil / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult