Left hemisphere motor facilitation in response to manual action sounds.
Previous studies indicate that the motor areas of both hemispheres are active when observing actions. Here we explored how the motor areas of each hemisphere respond to the sounds associated with actions. We used transcranial magnetic stimulation (TMS) to measure motor corticospinal excitability of hand muscles while listening to sounds. Sounds associated with bimanual actions produced greater motor corticospinal excitability than sounds associated with leg movements or control sounds. This facilitation was exclusively lateralized to the left hemisphere, the dominant hemisphere for language. These results are consistent with the hypothesis that action coding may be a precursor of language.
Aziz-Zadeh
Lisa
L
Ahmanson Lovelace Brain Mapping Center, Neuropsychiatric Institute, UCLA, 660 Charles E Young Dr. South, Los Angeles, CA90095-7085, USA. lazadeh@loni.ucla.edu
Iacoboni
Marco
M
Zaidel
Eran
E
Wilson
Stephen
S
Mazziotta
John
J
D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement; D018482:Muscle, Skeletal / Q000502:physiology; D010812:Physical Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology; D013016:Sound