title: Frontopolar activation during face-to-face conversation: an in situ study using near-infrared spectroscopy.
abstract: Near-infrared spectroscopy (NIRS) is a functional brain imaging technique for monitoring brain activation in a natural setting using near-infrared light, and hence, is considered to have some advantages for studies of brain function during social interactions such as face-to-face conversation compared with functional magnetic resonance imaging and positron emission tomography, which have methodological constraints for studying brain mechanisms underlying social interactions: subjects have to lie down on a bed in a small gantry during examination. The purpose of this study was to validate the possible use of NIRS as a functional brain imaging technique for studying social interactions in a natural setting; therefore, we investigated frontal and temporal lobe activation during face-to-face conversation in healthy subjects in the sitting position. The frontal and superior temporal regions were activated during face-to-face conversation, with higher activity in the speaking segments than in the mute segments during conversation particularly in frontopolar NIRS channels. The magnitude of frontopolar activity negatively correlated with the cooperativeness score of the subjects assessed using the temperament and character inventory. These results demonstrated the successful monitoring of brain function during realistic social interactions using NIRS and interindividual differences in frontopolar activity during conversation in relation to the cooperativeness of an individual.
authors.affiliation: Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Suda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takei
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Aoyama
authors.forename: Kosuke
authors.initials: K
authors.lastname: Narita
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Sato
authors.forename: Masato
authors.initials: M
authors.lastname: Fukuda
authors.forename: Masahiko
authors.initials: M
authors.lastname: Mikuni
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003299:Cooperative Behavior; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D009483:Neuropsychological Tests; D010555:Personality Inventory; D019265:Spectroscopy, Near-Infrared; D015898:Tomography Scanners, X-Ray Computed; D055815:Young Adult
chemical_list: D006454:Hemoglobins; C402601:hemoglobin glutamer-200