Investigating mood and the processing of dynamic facial and bodily expressions in people with Parkinson’s

Abstract

Parkinson’s Disease is a neurodegenerative condition which produces motor symptoms like tremors and non-motor symptoms like emotion processing, depression and anxiety. Non-motor symptoms like anxiety, depression, apathy, and emotion recognition impairment could affect quality of life and social interaction negatively. Chapter two investigated the effects of the UK’s first lockdown on People with Parkinson’s (PwP) on mood using quantitative and qualitative methods. This study revealed that PwP are more anxious than controls before the lockdown, and both groups showed an increase in anxiety during the lockdown. Thematic analysis was used to explore broader effects on mood and symptoms. The results are discussed in relation to better psychosocial support for PwP in general, as well as within possible future lockdowns. Emotion processing in Parkinson’s like emotion recognition is compromised due to neural deterioration in the limbic system and changes in the action observation system. Most previous studies have used static stimuli, but emotions are presented naturally in dynamic form. Thus, chapters three and four used dynamic stimuli. Chapter three consists of two studies, examining how PwP watch and feel about facially expressed dance, with and without music. Study one showed preliminary findings that PwP and controls were similarly affected by facially expressed versus non-expressed dance. However study 2, with more participants, showed that PwP did not report increased enjoyment and embodiment for facially expressed versus non-expressed dance, as observed for controls. This could be attributed to an impairment in the mirror neuron system, action observation, and emotion processing in PwP. Surprisingly, music was not preferred during watching dance by all participants, but that could be related to the unfamiliar or non-rhythmic music. Also, it highlighted the reduced benefit PwP have from watching facially expressed dance, hence the next study investigates facial emotional expressions presented in dynamic stimuli. In Chapter Four, we investigated PwP’s ability to recognise facial emotions from different stimuli, static and dynamic; and whether they recognise certain emotions better. We found that controls exhibited more accurate recognition from dynamic than static stimuli, however, PwP had slightly better recognition from static than dynamic stimuli. The emotion with the highest accuracy was surprise and the lowest was contempt across both groups. Depression affected emotion recognition negatively across both groups, whereas the effect of anxiety differed across emotions. Our findings show that controls were better able to identify emotions from dynamic than static facial expressions, but PwP did not show this benefit. Overall, this thesis investigated several elements of how PwP feel and experience mood, movement and emotion. Chapter 2 revealed how lockdown caused PwP additional anxiety that affected their mental health and wellbeing. However, it highlighted the need for remote support for PwP to maintain their wellbeing. The results from Chapters 3 and 4 reveal how PwP process emotions and expressions differently than others, especially from dynamic stimuli either presented in body form like dance or presented in facial expression on its own. This suggests that PwP do not process facial emotions in the same way as controls and do not benefit from naturalistic dynamic stimuli. This could be linked to difficulties producing emotional facial expressions and possible changes in the action observation system in Parkinson’s. Nevertheless, the fact that PwP enjoyed watching dance in Chapter three suggests that observation of dance in Parkinson's should be explored further and could be used as an adjunct to physical dance training for PwP to promote movement.

Date of Award	19 Dec 2023
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Ellen Poliakoff (Co Supervisor) & Karen Lander (Main Supervisor)