Not all sounds sound the same: Parkinson's disease affects differently emotion processing in music and in speech prosody

Abstract

Does emotion processing in music and speech prosody recruit common neurocognitive mechanisms? To examine this question, we implemented a cross-domain comparative design in Parkinson's disease (PD). Twenty-four patients and 25 controls performed emotion recognition tasks for music and spoken sentences. In music, patients had impaired recognition of happiness and peacefulness, and intact recognition of sadness and fear; this pattern was independent of general cognitive and perceptual abilities. In speech, patients had a small global impairment, which was significantly mediated by executive dysfunction. Hence, PD affected differently musical and prosodic emotions. This dissociation indicates that the mechanisms underlying the two domains are partly independent.

Keywords:

• Dissociation
• Emotion recognition
• Music
• Parkinson's disease
• Speech prosody

Acknowledgments

This research was supported by grants from the Portuguese Foundation for Science and Technology (COMPETE and FEDER programs) and from the Bial Foundation. We owe our thanks to the neurologists Fernanda Simões, João Massano, Maria José Rosas, Miguel Gago, and Sara Vieira, for help in recruiting patients; to Susana Carvalho, for assistance in testing participants; to Marc D. Pell, for insightful discussions on the design of the study; and to Anders Flykt and Arne Öhman, for making the Karolinska Directed Emotional Faces database available to us. The music stimuli were downloaded from the Isabelle Peretz Research Laboratory website (copyright © Bernard Bouchard, 1998).

Notes

¹Because accuracy rates for sadness and fear were relatively low (see Table 2), we cannot dismiss the possibility that the absence of differences between patients and controls for these emotions reflects a floor effect. To approach this concern, we reanalyzed the data considering only the subset of excerpts that reached the highest categorization accuracies (5 for sadness, 41% correct on average, and 5 for fear, 38% correct). This analysis confirmed that patients and controls did not differ (ps > .6). The fact that there were also no differences in the correlation data, which are immune to floor effects, lends further support to the conclusion that PD did not affect the recognition of sadness and fear in music.

²An inspection of Figure 1 suggests that the patients' prosodic difficulties were larger for sadness than for the other emotions. However, given that the interaction Group × Emotion was not significant, we refrained from analyzing possible emotion-specific effects, thereby avoiding Type I errors.

³To confirm that the lack of differences between patients and controls for fear was not due to the low accuracy rates obtained in this emotion (see Table 2), we have recalculated the ANOVA including only the subset of stimuli that reached the highest accuracies (34% correct on average); no effects of PD were detected (p > .6).