The essential role of Broca's area in imitation.

TitleThe essential role of Broca's area in imitation.
Publication TypeJournal Article
Year of Publication2003
AuthorsHeiser, M, Iacoboni M, Maeda F, Marcus J, Mazziotta JC
JournalThe European journal of neuroscience
Volume17
Issue5
Pagination1123-8
Date Published2003 Mar
ISSN0953-816X
KeywordsAdult, Brain Mapping, Electric Stimulation, Fingers, Frontal Lobe, Humans, Imitative Behavior, Magnetic Resonance Imaging, Magnetics, Male, Psychomotor Performance
Abstract

The posterior sector of Broca's area (Brodmann area 44), a brain region critical for language, may have evolved from neurons active during observation and execution of manual movements. Imaging studies showing increased Broca's activity during execution, imagination, imitation and observation of hand movements support this hypothesis. Increased Broca's activity in motor task, however, may simply be due to inner speech. To test whether Broca's area is essential to imitation, we used repetitive transcranial magnetic stimulation (rTMS), which is known to transiently disrupt functions in stimulated areas. Subjects imitated finger key presses (imitation) or executed finger key presses in response to spatial cues (control task). While performing the tasks, subjects received rTMS over the left and right pars opercularis of the inferior frontal gyrus (where Brodmann area 44 is probabilistically located) and over the occipital cortex. There was significant impairment in imitation, but not in the control task, during rTMS over left and right pars opercularis compared to rTMS over the occipital cortex. This suggests that Broca's area is a premotor region essential to finger movement imitation.

DOI10.1002/gps.3790
Alternate JournalEur. J. Neurosci.