Emotional Sentence Processing in Parkinson's Disease

Abstract

Purpose: Emotional processing allows us to predict our own and others' behavior, communicate our wants and needs, and understand those of others. Thus, deficits in emotional processing can negatively impact one's quality of life. While changes in emotional processing across several domains (e.g., prosody, faces) in Parkinson's disease (PD) are widely accepted, there is a dearth of literature, with equivocal results, regarding how emotional language processing is affected by PD. This study investigated emotional sentence processing in this population. Method: Eighteen persons with PD and 22 healthy adults (HAs) completed a language task in which they rated sentences on their pleasantness (valence), and a battery of cognitive tasks and mood measures that were examined as factors influencing performance. As an interaction between emotionality and concreteness during processing has been indicated in prior research, concreteness of sentence stimuli was also manipulated. Results: Individuals with PD rated negatively valenced sentences as less negative and positively-valenced sentences as less positive than HAs. The PD group also demonstrated a reduced overall range of valence rating scores. Sentence concreteness did not influence ratings. Results for positive sentences could be explained by individual differences in working memory (WM), whereas individual differences in WM, depression, and group explained differences in ratings to negative sentences. Conclusions: Our study provides one of few accounts of emotional language processing deficits in PD, particularly beyond the word level. Individuals with PD may experience difficulty perceiving and assessing the intensity of the emotional content of language, and deficits may disproportionately impact processing of sentences about negative situations. Supplemental Material: https://doi.org/10.23641/asha.21313713