Affective and sensorimotor components of emotional prosody generation

Abstract

Although advances have been made regarding how the brain perceives emotional prosody, the neural bases involved in the generation of affective prosody remain unclearanddebated.Twomodels have been forgedonthe basis of clinical observations: a firstmodelproposes that the right hemisphere sustains production and comprehension of emotional prosody, while a second model proposes that emotional prosody relies heavily on basal ganglia. Here, we tested their predictions in two functional magnetic resonance imaging experiments that used a cue-target paradigm, which allows distinguishing affectivefromsensorimotor aspects of emotional prosody generation. Both experimentsshowthatwhen participants prepare for emotional prosody, bilateral ventral striatum is specifically activated and connected to temporal poles and anterior insula, regions in which lesions frequently cause dysprosody. The bilateral dorsal striatum is more sensitive to cognitive and motor aspects of emotional prosody preparation and production and is more strongly connected to the sensorimotor speech network compared with the ventral striatum. Right lateralization during increased prosodic processing is confined to the posterior superior temporal sulcus, a region previously associated with perception of emotional prosody. Our data thus provide physiological evidence supporting both models and suggest that bilateral basal ganglia are involved inmodulatingmotorbehaviorasafunction of affective state.Rightlateralization of cortical regionsmobilized for prosody control could point to efficient processing of slowly changing acoustic speech parameters in the ventral stream and thus identify sensorimotor processing as an important factor contributing to right lateralization of prosody.