title: Neural basis of hierarchical visual form processing of Japanese Kanji characters.
abstract: We investigated the neural processing of reading Japanese Kanji characters, which involves unique hierarchical visual processing, including the recognition of visual components specific to Kanji, such as "radicals."
  
  
  
  We performed functional MRI to measure brain activity in response to hierarchical visual stimuli containing (1) real Kanji characters (complete structure with semantic information), (2) pseudo Kanji characters (subcomponents without complete character structure), (3) artificial characters (character fragments), and (4) checkerboard (simple photic stimuli).
  
  
  
  As we expected, the peaks of the activation in response to different stimulus types were aligned within the left occipitotemporal visual region along the posterior-anterior axis in order of the structural complexity of the stimuli, from fragments (3) to complete characters (1). Moreover, only the real Kanji characters produced functional connectivity between the left inferotemporal area and the language area (left inferior frontal triangularis), while pseudo Kanji characters induced connectivity between the left inferotemporal area and the bilateral cerebellum and left putamen.
  
  
  
  Visual processing of Japanese Kanji takes place in the left occipitotemporal cortex, with a clear hierarchy within the region such that the neural activation differentiates the elements in Kanji characters' fragments, subcomponents, and semantics, with different patterns of connectivity to remote regions among the elements.
authors.affiliation: Graduate School of Comprehensive Human Sciences University of Tsukuba Laboratory of Advanced Research D 1-1-1 Tennodai TsukubaIbaraki 305-8577 Japan; Japan Society for the Promotion of Science (JSPS) Research Fellow Kojimachi Business Center Building 5-3-1 Kojimachi Chiyoda Tokyo 102-0083 Japan; Department of Psychophysiology National Institute of Mental Health National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Higuchi
authors.affiliation: Department of Psychophysiology National Institute of Mental Health National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan; Integrative Brain Imaging Center National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Moriguchi
authors.affiliation: Department of Psychophysiology National Institute of Mental Health National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan; Department of Psychology Nagoya University Furo-cho Chikusa-ku Nagoya Aichi 464-8601 Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Murakami
authors.affiliation: Department of Psychophysiology National Institute of Mental Health National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan; Integrative Brain Imaging Center National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan.
authors.forename: Ruri
authors.initials: R
authors.lastname: Katsunuma
authors.affiliation: Department of Psychophysiology National Institute of Mental Health National Center of Neurology and Psychiatry 4-1-1 Ogawahigashi Kodaira Tokyo 187-0031 Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Mishima
authors.affiliation: Faculty of Human Sciences University of Tsukuba Laboratory of Advanced Research D 1-1-1 Tennodai Tsukuba Ibaraki 305-8577 Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Uno
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007564:Japan; D007600:Judgment / Q000502:physiology; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D011932:Reading; D055815:Young Adult
keywords: Hierarchical coding; Japanese logographic Kanji; Kanji radical; Left occipitotemporal cortex; visual character form