title: Dissociable cortical pathways for qualitative and quantitative mechanisms in the face inversion effect.
abstract: Humans' ability to recognize objects is remarkably robust across a variety of views unless faces are presented upside-down. Whether this face inversion effect (FIE) results from qualitative (distinct mechanisms) or quantitative processing differences (a matter of degree within common mechanisms) between upright and inverted faces has been intensely debated. Studies have focused on preferential responses to faces in face-specific brain areas, although face recognition also involves nonpreferential responses in non-face-specific brain areas. By using dynamic causal modeling with Bayesian model selection, here we show that dissociable cortical pathways are responsible for qualitative and quantitative mechanisms in the FIE in the distributed network for face recognition. When faces were upright, the early visual cortex (VC) and occipital and fusiform face areas (OFA, FFA) suppressed couplings to the lateral occipital cortex (LO), a primary locus of object processing. In contrast, they did not inhibit the LO when faces were inverted but increased couplings to the intraparietal sulcus, which has been associated with visual working memory. Furthermore, we found that upright and inverted face processing together involved the face network consisting of the VC, OFA, FFA, and inferior frontal gyrus. Specifically, modulatory connectivity within the common pathways (VC-OFA), implicated in the parts-based processing of faces, strongly correlated with behavioral FIE performance. The orientation-dependent dynamic reorganization of effective connectivity indicates that the FIE is mediated by both qualitative and quantitative differences in upright and inverted face processing, helping to resolve a central debate over the mechanisms of the FIE.
authors.affiliation: Department of Integrative Physiology, National Institute for Physiological Sciences, Aichi 444-8585, Japan, Department of Psychology, Graduate School of Human Sciences, Osaka University, Osaka 565-0871, Japan, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan, matsuyoshi@fennel.rcast.u-tokyo.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Matsuyoshi
authors.affiliation: Department of Integrative Physiology, National Institute for Physiological Sciences, Aichi 444-8585, Japan, Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan.
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Morita
authors.affiliation: ATR Brain Activity Imaging Center, Kyoto 619-0288 Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kochiyama
authors.affiliation: Department of Social and Human Environment, Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan, Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, Aichi 444-8585, Japan.
authors.forename: Hiroki C
authors.initials: HC
authors.lastname: Tanabe
authors.affiliation: Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, Aichi 444-8585, Japan, Department of Physiological Sciences, Graduate University for Advanced Studies, Kanagawa 240-0193, Japan, and Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan.
authors.forename: Norihiro
authors.identifier: http://orcid.org/0000-0002-9786-3907
authors.initials: N
authors.lastname: Sadato
authors.affiliation: Department of Integrative Physiology, National Institute for Physiological Sciences, Aichi 444-8585, Japan, Department of Physiological Sciences, Graduate University for Advanced Studies, Kanagawa 240-0193, Japan, and.
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Kakigi
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D005145:Face; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D013223:Statistics as Topic; D055815:Young Adult
keywords: dynamic causal modeling; fMRI; face inversion effect; inhibition; object recognition; visual working memory