Hemispheric specialization of the basal ganglia during vocal emotion decoding: Evidence from asymmetric Parkinson's disease and 18FDG PET

    loading  Checking for direct PDF access through Ovid


The possible hemispheric specialization of the basal ganglia during emotional prosody (i.e., vocal emotion) processing has still to be elucidated. Coupled with affective measures and neuroimaging, Parkinson's disease offers a unique opportunity to study this question, on account of its characteristically asymmetric striatal dysfunction, which translates into predominantly contralateral motor symptoms. We investigated the cerebral metabolic bases of emotional prosody recognition in patients with Parkinson's disease with left- versus right-lateralized motor symptoms, postulating that patients with greater right hemispheric brain dysfunction have a specific impairment that correlates with the metabolic modification of a brain network known to be involved in emotional prosody. A total of 38 patients performed a validated emotional prosody recognition task and underwent a resting-state F-18 fluorodeoxyglucose PET scan, as well as clinical, motor, neuropsychological, and psychiatric assessments. Patients' performances were compared with those of 45 healthy controls. As expected, vocal emotion recognition was significantly poorer among patients with left-sided motor symptoms than among both right-sided patients and controls. There was no significant difference between right-sided patients and controls. This effect was observed for both the total score and the happiness subscore. Interestingly, regressions showed that the greater the emotional misattribution, the greater the patients' age and asymmetric motor symptom severity. Finally, at the metabolic level, positive correlations were found between the happiness recognition subscore and the metabolism of the right orbitofrontal cortex in patients with left-sided motor symptoms. A right orbitofrontal-basal ganglia coupling seems to be specifically involved in the vocal emotion recognition deficit observed in Parkinson's disease. The asymmetry of motor symptoms is thus an important clinical factor, in that it may influence the presence or severity of affective disorders in Parkinson's disease.Graphical abstractHighlightsWe explored the impact of lateralized motor symptoms on vocal emotion in PD.Only left-lateralized PD patients presented a vocal emotion deficit.This deficit correlated with glucose metabolism in the right orbito-frontal cortex.This suggests a specific role of right fronto-striatal network in vocal emotion.Brain hemispheric specialization in emotional prosody is discussed.

    loading  Loading Related Articles