title: 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 1School of Mechatronic Engineering, University Malaysia Perlis (UniMAP), Malaysia.
authors.forename: R
authors.initials: R
authors.lastname: Yuvaraj
authors.forename: M
authors.initials: M
authors.lastname: Murugappan
authors.forename: Mohd Iqbal
authors.initials: MI
authors.lastname: Omar
authors.forename: Norlinah Mohamed
authors.initials: NM
authors.lastname: Ibrahim
authors.forename: Kenneth
authors.initials: K
authors.lastname: Sundaraj
authors.forename: Khairiyah
authors.initials: K
authors.lastname: Mohamad
authors.forename: M
authors.initials: M
authors.lastname: Satiyan
mesh_terms: D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology* / Q000523:psychology; D021641:Recognition, Psychology / Q000502:physiology*; D012938:Social Perception
keywords: Parkinson's disease; electroencephalogram; emotion; relative spectral power