[Perception of musical sounds: contributions of positron emission tomography]

The perception of music is not a single global process. It encompasses the integration into conscience of various elements, such as sound pitch, tone, rhythm and impression of familiarity. Thus, it may be subjected to cognitive studies based on specific and complementary abilities of both cerebral hemispheres in these tasks. A number of selected medical cases reported previously had already suggested anatomic-clinical correlations for the perception of the various components of musical sounds. The left hemisphere subserves rhythm and pitch perception, the sense of familiarity and identification of a musical piece. The right hemisphere plays a part in the perception of tone and melodic line. Position emission tomographic studies in normal subjects have corroborated these assumptions on hemispheric lateralization in musical perception. In addition, they have demonstrated previously unsuspected facts, such as the role of visual areas in pitch perception and the role of frontal cortex and especially of Broca's area in the perception of rhythm.