Emotion processing in Parkinson's disease: an EEG spectral power study

Abstract

Objective: Although an emotional deficit is a common finding in Parkinson's disease (PD), its neurobiological mechanism on emotion recognition is still unknown. This study examined the emotion processing deficits in PD patients using electroencephalogram (EEG) signals in response to multimodal stimuli. Method: EEG signals were investigated on both positive and negative emotions in 14 PD patients and 14 aged-matched normal controls (NCs). The relative power (i.e., ratio of EEG signal power in each frequency band compared to the total EEG power) was computed over three brain regions: the anterior (AF3, F7, F3, F4, F8 and AF4), central (FC5 and FC6) and posterior (T7, P7, O1, O2, P8 and T8) regions for theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz) and gamma (30–60 Hz) frequency sub-bands, respectively. Results: Behaviorally, PD patients showed decreased performance in classifying emotional stimuli as measured by subjective ratings. EEG power at theta, alpha, beta, and gamma bands in all regions were significantly different between the NC and PD groups during both the emotional tasks, with p-values less than 0.05. Furthermore, an increase of relative spectral powers in the theta and gamma bands and a decrease of relative powers in the alpha and beta bands were observed for PD patients compared with NCs during emotional information processing. Conclusion: The results suggest the possibility of the existence of a distinctive neurobiological substrate of PD patients during emotional information processing. Also, these distributed spectral powers in different frequency bands might provide meaningful information about emotional processing in PD patients.

KEYWORDS: :

• emotion
• electroencephalogram
• Parkinson's disease
• relative spectral power

Notice of Correction

The version of this article published online ahead of print on 22 Nov 2013 contained an error in the affiliation details. Khairiyah Mohamad is affiliated with affiliation 2 (Neurology Unit, Department of Medicine, UKM Medical Center, Kuala Lumpur, Malaysia) and not affiliation 3 (Department of Clinical Psychology, Neurology Unit, UKM Medical Center, Perlis, Malaysia), which has been removed. Also, on page 2, the sentence “This study was approved by the University Kebangsaang Malaysia (UKM) Ethics Board, Kuala Lumpur, Malaysia…” should have read “This study was approved by the University Kebangsaan Malaysia (UKM) Ethics Board, Kuala Lumpur, Malaysia…”. Furthermore, on page 5, under the results section, “PD/HC” should have read “PD/NC” and on page 8, in table 4, the column header “p-Value” should have read “p-Value*”. The errors have been corrected for this version.