Functional contributions of the basal ganglia to emotional prosody: evidence from ERPs.

The basal ganglia (BG) have been functionally linked to emotional processing [Pell, M.D., Leonard, C.L., 2003. Processing emotional tone form speech in Parkinson's Disease: a role for the basal ganglia. Cogn. Affec. Behav. Neurosci. 3, 275-288; Pell, M.D., 2006. Cerebral mechanisms for understanding emotional prosody in speech. Brain Lang. 97 (2), 221-234]. However, few studies have tried to specify the precise role of the BG during emotional prosodic processing. Therefore, the current study examined deviance detection in healthy listeners and patients with left focal BG lesions during implicit emotional prosodic processing in an event-related brain potential (ERP)-experiment. In order to compare these ERP responses with explicit judgments of emotional prosody, the same participants were tested in a follow-up recognition task. As previously reported [Kotz, S.A., Paulmann, S., 2007. When emotional prosody and semantics dance cheek to cheek: ERP evidence. Brain Res. 1151, 107-118; Paulmann, S. & Kotz, S.A., 2008. An ERP investigation on the temporal dynamics of emotional prosody and emotional semantics in pseudo- and lexical sentence context. Brain Lang. 105, 59-69], deviance of prosodic expectancy elicits a right lateralized positive ERP component in healthy listeners. Here we report a similar positive ERP correlate in BG-patients and healthy controls. In contrast, BG-patients are significantly impaired in explicit recognition of emotional prosody when compared to healthy controls. The current data serve as first evidence that focal lesions in left BG do not necessarily affect implicit emotional prosodic processing but evaluative emotional prosodic processes as demonstrated in the recognition task. The results suggest that the BG may not play a mandatory role in implicit emotional prosodic processing. Rather, executive processes underlying the recognition task may be dysfunctional during emotional prosodic processing.