title: Load effect on background rhythms during motor execution: A magnetoencephalographic study.
abstract: We investigated the effect of load against self-paced movement on cortical involvement for motor execution. Ten right-handed healthy volunteers were requested to perform brisk extension of the right index finger at self-paced intervals exceeding 10s for three load conditions: 0g, 50g and 100g. Movement-related magnetic fields were recorded using an MEG system. The signals were band-pass-filtered through 18-23Hz and rectified before averaging with respect to EMG onset. We analyzed the time course and %change of peak amplitude with reference to the baseline amplitude in event-related desynchronization (ERD) or synchronization (ERS) in each hemisphere. Maximum response was observed around the left somatomotor area for all conditions. ERD did not show any significant difference before the movement onset among the three load conditions. For %change, ERS in the post-movement period was significantly larger for the 100g load condition than for the 0g load condition, and that was significantly greater over the left than over the right hemisphere. These findings indicate that the load has little effect on pre-movement desynchronization, whereas it affects the post-movement synchronization on background rhythms.
authors.affiliation: Department of Neurology, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan; Sapporo Shirakaba-dai Hospital, 2-18, Tsukisamu-higashi, Toyohira-ku, Sapporo 062-0052, Japan.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Toyoshima
authors.affiliation: Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Yazawa
authors.affiliation: Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Murahara
authors.affiliation: Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Ishiguro
authors.affiliation: Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Shinozaki
authors.affiliation: Department of Occupational Therapy, School of Health Science, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Satoe
authors.initials: S
authors.lastname: Ichihara-Takeda
authors.affiliation: Department of Pediatrics, Hokkaido University School of Medicine, North 15, West 7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiraishi
authors.affiliation: Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Syogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Matsuhashi
authors.affiliation: Department of Neurology, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Shimohama
authors.affiliation: Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo 060-8556, Japan. Electronic address: nagamine@sapmed.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagamine
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009068:Movement; D010507:Periodicity; D013997:Time Factors; D016474:Weight-Bearing
keywords: Event-related desynchronization; Event-related synchronization; Magnetoencephalography; Motor cortex; Self-paced movement; Weight loading