[Hemispheric asymmetry in amusia]

The search of hemispheric dominance for music has been for long the main aim of the study of amusias. Musical abilities were first localized in the left hemisphere, then in the right one. In the light of the available data, these two diverging conceptions do not appear paradoxical anymore. Indeed, brain injury on either side can provoke musical deficits. However, the nature of the deficit seems to depend on the particular hemisphere damaged. Right-sided lesions appear to disturb the melodic aspects of musical sequences while left-sided lesions seem to deteriorate the rhythmic aspects. Although the clinical literature involves insightful suggestions on how the musical abilities are organized, especially with respect to linguistic functions, these indications are not sufficient to provide a clear picture of the nature of the functional differences for music between hemispheres. Research is not systematic. Commentaries and suggestions are proposed to guide future investigations.