title: Altered Kinematics of Facial Emotion Expression and Emotion Recognition Deficits Are Unrelated in Parkinson's Disease.
abstract: BACKGROUND
  Altered emotional processing, including reduced emotion facial expression and defective emotion recognition, has been reported in patients with Parkinson's disease (PD). However, few studies have objectively investigated facial expression abnormalities in PD using neurophysiological techniques. It is not known whether altered facial expression and recognition in PD are related.
  
  
  OBJECTIVE
  To investigate possible deficits in facial emotion expression and emotion recognition and their relationship, if any, in patients with PD.
  
  
  METHODS
  Eighteen patients with PD and 16 healthy controls were enrolled in this study. Facial expressions of emotion were recorded using a 3D optoelectronic system and analyzed using the facial action coding system. Possible deficits in emotion recognition were assessed using the Ekman test. Participants were assessed in one experimental session. Possible relationship between the kinematic variables of facial emotion expression, the Ekman test scores, and clinical and demographic data in patients were evaluated using the Spearman's test and multiple regression analysis.
  
  
  RESULTS
  The facial expression of all six basic emotions had slower velocity and lower amplitude in patients in comparison to healthy controls (allPs < 0.05). Patients also yielded worse Ekman global score and disgust, sadness, and fear sub-scores than healthy controls (allPs < 0.001). Altered facial expression kinematics and emotion recognition deficits were unrelated in patients (allPs > 0.05). Finally, no relationship emerged between kinematic variables of facial emotion expression, the Ekman test scores, and clinical and demographic data in patients (allPs > 0.05).
  
  
  CONCLUSIONS
  The results in this study provide further evidence of altered emotional processing in PD. The lack of any correlation between altered facial emotion expression kinematics and emotion recognition deficits in patients suggests that these abnormalities are mediated by separate pathophysiological mechanisms.
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy; Neuromed Institute IRCCS, Pozzilli, Isernia, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bologna
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome , Rome , Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Berardelli
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome , Rome , Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Paparella
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome , Rome , Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Marsili
authors.affiliation: St George's University of London , London , UK.
authors.forename: Lucia
authors.initials: L
authors.lastname: Ricciardi
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy; Neuromed Institute IRCCS, Pozzilli, Isernia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fabbrini
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy; Neuromed Institute IRCCS, Pozzilli, Isernia, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
keywords: Parkinson’s disease; bradykinesia; emotion; hypomimia; motor control