title: Influence of somatosensory input on corticospinal excitability during motor imagery.
abstract: Our previous studies showed that corticospinal excitability during imagery of squeezing a foam ball was enhanced by somatosensory input generated by passively holding the ball. In the present study, using the same experimental model, we investigated whether corticospinal excitability was influenced by holding the object with the hand opposite to the imagined hand. Corticospinal excitability was assessed by monitoring motor evoked potentials (MEPs) in the first dorsal interosseous muscle following transcranial magnetic stimulation over the motor cortex during motor imagery. Subjects were asked to imagine squeezing a foam ball with the right hand (experiment 1) or the left hand (experiment 2), while either holding nothing (Null condition), a ball in the right hand (Right condition) or a ball in the left hand (Left condition). The MEPs amplitude during motor imagery was increased, only when the holding hand and the imagined hand were on the same side. These results suggest that performance improvement and rehabilitation exercises will be more effective when somatosensory stimulation and motor imagery are done on the same side.
authors.affiliation: Graduate School of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan. mizuguchi@suou.waseda.jp
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Mizuguchi
authors.forename: Masanori
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Muraoka
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Moriyama
authors.forename: Kento
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakata
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kanosue
mesh_terms: D000328:Adult; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007092:Imagination / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation