Cortical sensorimotor control in vocalization: a functional magnetic resonance imaging study.

ABSTRACT

BACKGROUND: Verbal communication is a human feature and volitional vocalization is its basis. However, little is known regarding the cortical areas involved in human vocalization. METHODS: Therefore, functional magnetic resonance imaging at 3 Tesla was performed in 16 healthy adults to evaluate brain activations related to voice production. The main experiments included tasks involving motor control of laryngeal muscles with and without intonation. In addition, reference mappings of the sensorimotor hand area and the auditory cortices were performed. RESULTS: Related to vocalization, in addition to activation of the most lateral aspect of the primary sensorimotor cortex close to the Sylvian fissure (M1c), we found activations medially (M1a) and laterally (M1b) of the well-known sensorimotor hand area. Moreover, the supplementary motor area and the anterior cingulate cortex were activated. CONCLUSIONS: Although M1a could be ascribed to motor control of breathing, M1b has been associated with laryngeal motor control. Consequently, even though M1c represents a laryngeal sensorimotor area, its exclusiveness as suggested previously could not be confirmed. Activations in the supplementary motor area and anterior cingulate cortex were ascribed to "vocal-motor planning." The present data provide the basis for further functional magnetic resonance imaging studies in patients with neurological laryngeal disorders.