title: Effects of motor imagery are dependent on motor strategies.
abstract: To investigate whether the facilitatory effects of motor imagery (MI) are dependent on motor strategies that vary with posture, we used transcranial magnetic stimulation to examine the effects of two forearm positions on motor-evoked potentials during an MI of index-finger abduction. MI-enhanced motor-evoked potentials of the first dorsal interosseous (prime mover) muscle in the forearm prone position were larger than those in the forearm neutral position. The opposite effects were seen in the extensor carpi radialis (synergist) muscle. These effects correspond to the different electromyography activities in the muscles when performing the actual movements in these two forearm positions. It is suggested that MI reflects different motor strategies in the contribution of agonist and synergist muscles towards a motor task.
authors.affiliation: Department of Rehabilitation of Locomotor System Dysfunction, Graduate School of Health Sciences, Hiroshima University, 1-2-3 Kasumi, Japan.
authors.forename: Nan
authors.initials: N
authors.lastname: Liang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Ni
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.forename: Tsuneji
authors.initials: T
authors.lastname: Murakami
authors.forename: Susumu
authors.initials: S
authors.lastname: Yahagi
authors.forename: Kozo
authors.initials: K
authors.lastname: Funase
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kasai
mesh_terms: D000328:Adult; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005385:Fingers / Q000294:innervation / Q000502:physiology; D005542:Forearm / Q000294:innervation / Q000502:physiology; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation