title: Neural substrates of human facial expression of pleasant emotion induced by comic films: a PET Study.
abstract: Laughter or smile is one of the emotional expressions of pleasantness with characteristic contraction of the facial muscles, of which the neural substrate remains to be explored. This currently described study is the first to investigate the generation of human facial expression of pleasant emotion using positron emission tomography and H(2)(15)O. Regional cerebral blood flow (rCBF) during laughter/smile induced by visual comics and the magnitude of laughter/smile indicated significant correlation in the bilateral supplementary motor area (SMA) and left putamen (P < 0.05, corrected), but no correlation in the primary motor area (M1). In the voluntary facial movement, significant correlation between rCBF and the magnitude of EMG was found in the face area of bilateral M1 and the SMA (P < 0.001, uncorrected). Laughter/smile, as opposed to voluntary movement, activated the visual association areas, left anterior temporal cortex, left uncus, and orbitofrontal and medial prefrontal cortices (P < 0.05, corrected), whereas voluntary facial movement generated by mimicking a laughing/smiling face activated the face area of the left M1 and bilateral SMA, compared with laughter/smile (P < 0.05, corrected). We demonstrated distinct neural substrates of emotional and volitional facial expression and defined cognitive and experiential processes of a pleasant emotion, laughter/smile.
authors.affiliation: Psychiatry, and Department of Clinical Neuroscience, Osaka University Graduate School of Medicine, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Iwase
authors.forename: Yasuomi
authors.initials: Y
authors.lastname: Ouchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okada
authors.forename: Chihiro
authors.initials: C
authors.lastname: Yokoyama
authors.forename: Shuji
authors.initials: S
authors.lastname: Nobezawa
authors.forename: Etsuji
authors.initials: E
authors.lastname: Yoshikawa
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsukada
authors.forename: Masaki
authors.initials: M
authors.lastname: Takeda
authors.forename: Ko
authors.initials: K
authors.lastname: Yamashita
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takeda
authors.forename: Kouzi
authors.initials: K
authors.lastname: Yamaguti
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kuratsune
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D016000:Cluster Analysis; D003071:Cognition / Q000502:physiology; D004576:Electromyography; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005152:Facial Muscles / Q000502:physiology; D005260:Female; D006801:Humans; D007845:Laughter / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014055:Tomography, Emission-Computed