Music & Language Studies

RIECKER, Axel, et al. “Opposite Hemispheric Lateralization Effects During Speaking and Singing at Motor Cortex, Insula and Cerebellum.” NeuroReport 11/9 (2000):1997-2000.

The authors discuss previous findings which indicate the production of language (words) and the production of melodies may be handled by “different cerebral networks.” (1997-1998) However, they point out that speaking and singing may in fact encompass both components, words and melodies combined. They contend that

in order to test the hypothesis that different networks support the generation of speech and melodies, sound structure and tonal aspects of acoustic communication must be teased apart. (1998)

That is, it is necessary to distinguish between aspects of intonation which convey purely linguistic information (i.e. type of utterance: statement, question, command; or, lexical stress: distinguishing PRESENT or CORRELATE [noun] from PRESENT or CORRELATE [verb]) from those communicating emotional cues. For the present study, eighteen healthy right-handed subjects were asked to speak the months of the year, and to sing a well-known instrumental tune without lyrics (derived from W. A. Mozart’s Eine Kleine Nachtmusik, and familiar to all subjects), while undergoing fMRI. Additionally, in order to control for possible differences between overt and covert modalities, each of the tasks were performed aloud and silently. Extensive analysis of variation was conducted across experimental conditions. Findings reported specific localization of activity during tasks, which differed for each condition, including overt vs. covert performance. The effects were strongest for covert singing and silent speech, producing clear opposite lateralization effects in the right motor cortex/posterior inferior frontal gyrus and left cerebellum for song, and the opposite for speech. Bilateral activation in these regions was noted for overt tasks, with moderate lateralizations corresponding to those for covert performance. They conclude:

Two opposite cerebral networks comprising motor cortex, anterior insula, and cerebellum subserve speaking and singing, respectively. Since activation of the insula revealed to be bound to overt performance, this structure seems to mediate actual implementation of speech (words) and melody (tunes) patterns in terms of temporal spatial coordination of vocal tract musculature. (2000)