Human primary motor cortex is both activated and stabilized during observation of other person's phasic motor actions.
When your favourite athlete flops over the high-jump bar, you may twist your body in front of the TV screen. Such automatic motor facilitation, 'mirroring' or even overt imitation is not always appropriate. Here, we show, by monitoring motor-cortex brain rhythms with magnetoencephalography (MEG) in healthy adults, that viewing intermittent hand actions of another person, in addition to activation, phasically stabilizes the viewer's primary motor cortex, with the maximum of half a second after the onset of the seen movement. Such a stabilization was evident as enhanced cortex-muscle coherence at 16-20 Hz, despite signs of almost simultaneous suppression of rolandic rhythms of approximately 7 and 15 Hz as a sign of activation of the sensorimotor cortex. These findings suggest that inhibition suppresses motor output during viewing another person's actions, thereby withholding unintentional imitation.
Brain Research Unit, O.V. Lounasmaa Laboratory, Aalto University, , 00076 AALTO, Espoo, Finland.
Riitta
R
Hari
Mathieu
M
Bourguignon
Harri
H
Piitulainen
Eero
E
Smeds
Xavier
X
De Tiège
Veikko
V
Jousmäki
D000328:Adult; D004576:Electromyography; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D007100:Imitative Behavior / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology*; D019370:Observation; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*
brain rhythms; imitation; inhibition; motor cortex