Multi-modal lesion mapping of expressive aprosodia

Affective prosody facilitates the communication of emotions by modulating paralinguistic features of speech (e.g., pitch and rhythm). Patients with brain injuries may exhibit impaired expression of affective prosody, referred to as expressive aprosodia, adversely impacting social interactions and quality of life. Despite many previous lesion studies, relatively few studies have investigated neural correlates of expressive aprosodia using a combination of lesion location, as well as associated structural and functional network mapping, within a large patient sample. There is especially a need to advance our understanding of the neurobiology associated with expressive aprosodia in the chronic phase (i.e., >3 months after lesion onset) given the practical importance of long-term outcomes in regard to social functioning and quality of life. The present study therefore aimed to characterize how expressive aprosodia relates to lesion location and disruption of associated structural and functional brain networks in a large sample of participants with chronic focal brain lesions (N = 673). Using a clinical expert evaluation of prosody and multi-modal lesion mapping, the results showed that expressive aprosodia was most strongly associated with i) lesions affecting right-lateralized fronto-insular-striatal regions, ii) prominent disconnection of right-lateralized cortico-subcortical pathways, and iii) damage to regions exhibiting functional connectivity with subcortical (basal ganglia, thalamus) and cortical ventral attention/salience networks. Overall, these findings are consistent with a previously proposed dorsal stream for expressive aprosodia and provide further insights into the neural architecture whose damage is associated with chronic expressive aprosodia.