The essential role of Broca's area in imitation.

Full 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.

Author information

Author/s: Heiser, Marc (M); Iacoboni, Marco (M); Maeda, Fumiko (F); Marcus, Jake (J); Mazziotta, John C (JC);

Affiliation: Ahmanson-Lovelace Brain Mapping Center, Neuropsychiatric Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.

Grants: RR08655 (Agency:NCRR NIH HHS) ; RR12169 (Agency:NCRR NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.

Journal: The European journal of neuroscience (Eur J Neurosci), published in France. (Language: eng)

Reference: 2003-Mar; vol 17 (issue 5) : pp 1123-8

Dates: Created 2003/03/25; Completed 2003/05/15; Revised 2007/11/14;

PMID: 12653990, status: MEDLINE (last retrieved date: 2/18/2009)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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