How does prosodic deficit impact naïve listeners recognition of emotion? An analysis with speakers affected by Parkinson’s disease

This study aimed to understand the impact of the prosodic deficit in Parkinson’s disease (PD) on the communicative effectiveness of vocal expression of emotion. Fourteen patients with PD and 13 healthy control subjects (HC) uttered the phrase “non è possible, non ora” (“It is not possible, not now”) six times reading different emotional narrations. Three experts evaluated the PD subjects’ vocal production in terms of their communicative effectiveness. The PD patients were divided into two groups: PD+ (with residual effectiveness) and PD− (with impaired effectiveness). The vocal productions were administered to 30 naïve listeners. They were requested to label the emotion they recognized and to make judgments about their communicative effectiveness. The PD speakers were perceived as less effective than the HC speakers in conveying emotions (especially fear and anger). The PD− group was the most impaired in the expression of emotion, suggesting that speech disorders impact differently at the same stage of the disease with varying degrees of severity.