Music and Affective Prosody after Surgical Removal of the Right Arcuate Fasciculus: A Case Study.

The right hemisphere of the human brain plays an important role in music processing, with lateralized functions for pitch, meter, and melody recognition among other features. However, the relationship between white matter and music processing is relatively little explored. We report a case study of a 50-year-old musician with a right parieto-insular brain tumor who underwent resective surgery. Post-surgical diffusion tensor imaging revealed that the integrity of the right frontal aslant tract and the ventral pathway of the patient was preserved, whereas the right dorsal pathway (arcuate fasciculus and portions of parietal and insular cortex) was largely removed. A comprehensive neuropsychological evaluation revealed that the patient did not present language, receptive prosody, or cognitive deficits after the tumor removal, with the exception of a selective impairment in recognizing the emotion of fear in prosody. Moreover, the patient showed no signs of amusia, and did not report any problem with musical activities or music -related emotional processing. The only subjective report concerned rhythmic abilities. This case study suggests that the right dorsal stream does not subserve musical and receptive affective prosody processing, contributing to the ongoing debate of white matter correlates of these cognitive functions.