title: Language-related cerebral oscillatory changes are influenced equally by genetic and environmental factors.
abstract: Twin studies have suggested that there are genetic influences on inter-individual variation in terms of verbal abilities, and candidate genes have been identified by genome-wide association studies. However, the brain activities under genetic influence during linguistic processing remain unclear. In this study, we investigated neuromagnetic activities during a language task in a group of 28 monozygotic (MZ) and 12 dizygotic (DZ) adult twin pairs. We examined the spatio-temporal distribution of the event-related desynchronizations (ERDs) in the low gamma band (25-50Hz) using beamformer analyses and time-frequency analyses. Heritability was evaluated by comparing the respective MZ and DZ correlations. The genetic and environmental contributions were then estimated by structural equation modeling (SEM). We found that the peaks of the low gamma ERDs were localized to the left frontal area. The power of low gamma ERDs in this area exhibited higher similarity between MZ twins than that between DZ twins. SEM estimated the genetic contribution as approximately 50%. In addition, these powers were negatively correlated with the behavioral verbal scores. These results improve our understanding of how genetic and environmental factors influence cerebral activities during linguistic processes.
authors.affiliation: Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Department of Medical Technology, Osaka University Hospital, Suita, Osaka 565-0871, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Araki
authors.affiliation: Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Department of Neurosurgery, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan. Electronic address: mhirata@nsurg.med.osaka-u.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hirata
authors.affiliation: Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Department of Neurosurgery, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Takufumi
authors.initials: T
authors.lastname: Yanagisawa
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Faculty of Welfare and Health Science, Oita University, Dannoharu, Oita, Japan.
authors.forename: Hisato
authors.initials: H
authors.lastname: Sugata
authors.affiliation: Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Onishi
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Health Promotion Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Research Fellow of Japan Society for the Promotion of Science, Japan.
authors.forename: Soshiro
authors.initials: S
authors.lastname: Ogata
authors.affiliation: Center for Twin Research, Osaka University Medical School, Suita, Osaka 565-0871, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Honda
authors.affiliation: Mie Prefectural College of Nursing, Tsu, Mie 514-0116, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hayakawa
authors.affiliation: Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Yorifuji
mesh_terms: D000328:Adult; D000368:Aged; D058407:Electroencephalography Phase Synchronization / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D065818:Gamma Rhythm / Q000502:physiology*; D059647:Gene-Environment Interaction; D006801:Humans; D007802:Language; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D011932:Reading; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
keywords: Genetic influence; Language; Magnetoencephalography; Oscillation; Twin study