Nature384, 159 - 161
(14 November 1996); doi:10.1038/384159a0
A new brain region for coordinating speech articulation
Nina F. Dronkers
VA Northern California Health Care System, 150 Muir Road (126s), Martinez, California 94553, USA and Departments of Neurology and Linguistics, University of California, Davis, California 95616, USA
HUMAN speech requires complex planning and coordination of mouth and tongue movements. Certain types of brain injury can lead to a condition known as apraxia of speech, in which patients are impaired in their ability to coordinate speech movements but their ability to perceive speech sounds, including their own errors, is unaffected1,3. The brain regions involved in coordinating speech, however, remain largely unknown. In this study, brain lesions of 25 stroke patients with a disorder in the motor planning of articulatory movements were compared with lesions of 19 patients without such deficits. A robust double dissociation was found between these two groups. All patients with articulatory planning deficits had lesions that included a discrete region of the left precentral gyms of the insula, a cortical area beneath the frontal and temporal lobes. This area was completely spared in all patients without these articulation deficits. Thus this area seems to be specialized for the motor planning of speech.