Opposite hemispheric lateralization effects during speaking and singing atmotor cortex, insula and cerebellum

Aside from spoken language, singing represents a second mode of acoustic: ( auditory-vocal) communication in humans. As a new aspect of brain lateraliz ation, functional magnetic resonance imaging (fMRI) revealed two complement ary cerebral networks subserving singing and speaking. Reproduction of a no n-lyrical tune elicited activation predominantly in the right motor cortex, the right anterior insula, and the left cerebellum whereas the opposite re sponse pattern emerged during a speech task. In contrast to the hemodynamic responses within motor cortex and cerebellum, activation of the intrasylvi an cortex turned out to be bound to overt task performance. These findings corroborate the assumption that the left insula supports the coordination o f speech articulation. Similarly, the right insula might mediate temporo-sp atial control of vocal tract musculature during overt singing. Both speech and melody production require the integration of sound structure or tonal p atterns, respectively, with a speaker's emotions and attitudes. Considering the widespread interconnections with premotor cortex and limbic structures , the insula is especially suited for this task. NeuroReport 11:1997-2000 ( C) 2000 Lippincott Williams & Wilkins.