title: Combining observation and imagery of an action enhances human corticospinal excitability.
abstract: The present study investigated whether combining observation and imagery of an action increased corticospinal excitability over the effects of either manipulation performed alone. Corticospinal excitability was assessed by motor-evoked potentials in the biceps brachii muscle following transcranial magnetic stimulation over the motor cortex during observation, imagery or both. The action utilized was repetitive elbow flexion/extension. Simultaneous observation and imagery of the elbow action facilitated corticospinal excitability as compared to that recorded during observation or imagery alone. However, facilitation due to the combination of observation and imagery was not obtained when the participants imagined the action pattern while they observed the same action presented out of phase. These findings suggest that a combination of observation and imagery can enhance corticospinal excitability. This enhancement depends on phase consistency between the observed and imagined actions.
authors.affiliation: Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan. msakamoto@aoni.waseda.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Muraoka
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Mizuguchi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kanosue
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D004576:Electromyography; D019054:Evoked Potentials, Motor; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007100:Imitative Behavior; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation