Effects of happy and sad facial expressions on the perception of time in Parkinson’s disease patients with mild cognitive impairment

ABSTRACT

Introduction: Parkinson’s disease (PD) is a movement disorder caused by deterioration of the dopaminergic system. Previous studies have demonstrated temporal as well as emotional facial recognition impairment in PD patients. Moreover, it has been demonstrated that emotional facial expressions alter temporal judgments. In the present study, we investigate the magnitude of temporal distortions caused by the presentation of emotional facial expressions (happiness, sadness, and neutral) in PD patients with mild cognitive impairment (PD-MCI) and controls.

Method: Seventeen older adults with PD-MCI and 22 healthy older adults took part in the present study. Participants were tested with a time bisection task with standard intervals lasting 400 ms and 1600 ms. Moreover, a complete neuropsychological evaluation was conducted to characterize the sample.

Results: Differences between groups were observed indicating a general underestimation of time in PD-MCI patients. Temporal impairments in PD-MCI patients seem to be caused mainly by a dysfunction at the level of reference memory. The effect of emotional facial expressions on time perception was evident in both PD patients and controls, with an overestimation of perceived duration when happiness was presented and an underestimation when sadness was presented.

Conclusion: Overall, our results indicate that reduced cognitive abilities might be responsible for the lower temporal ability observed in PD-MCI patients. Moreover, similar effects of emotional stimuli were observed in both PD-MCI patients and controls.

KEYWORDS:

• Emotional facial recognition
• Parkinson’s disease patients
• time bisection task
• time perception

Acknowledgments

The information in this manuscript and the manuscript itself has never been published either electronically or in print. There are no financial or other relationships that could be interpreted as a conflict of interest affecting this manuscript. This research received no specific grant from any funding agency from either the commercial or the not-for-profit sectors. The authors gratefully acknowledge Martina Argentieri and Sara Stefanelli for their help in collecting data, and Shelley Peery and the “Research Editing and Consulting Program” for assisting with English editing. The authors also gratefully acknowledge the staff of the Ospedale S. Bortolo, Vicenza, Italy, and the participants, their families, and friends who participated in this study. We would like to extend a special thanks to two anonymous reviewers for their most helpful comments and suggestions on previous drafts of this article.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Please refer to Jones and Jahanshahi (2014) for a detailed review of temporal dysfunction in PD patients with other temporal tasks.

2. Please see Posner, Russellc, and Peterson (2005) and Russell and Bullock (1985) for a different approach on facial emotional recognition. Our consideration of sadness as an arousing emotion is driven by previous studies conducted by Droit-Volet and her team on the effects of facial emotional stimuli on time perception. Although sadness might not be an arousing emotion per se, the view of a face expressing sadness seems to have some arousing effect on the observer.

3. Preliminary analyses were conducted to control for the effect of gender of participants and stimuli. Neither main effect of gender of participants or gender of stimuli nor interactions were found (p > .05). We used a least square fitting procedure.