title: Trust behavior in Parkinson's disease: results of a trust game experiment.
abstract: BACKGROUND
  Parkinson's Disease (PD) is a neurodegenerative disease characterized by motor symptoms, but in which behavioral and cognitive disturbances are also common. Trust, due to its pervasiveness in society, has become a major research topic in several scientific disciplines. However, empirical evidence for trust behavior in neurological patients, and specifically for movement disorders such as PD, is missing. Evidence from healthy subjects, however, indicates that three brain regions are involved in trust perceptions and behavior, namely the limbic system, basal ganglia, and frontal cortex. PD affects all these brain regions. Therefore, we hypothesized that PD patients and healthy controls show differences in trust behavior.
  
  
  METHODS
  We conducted an experiment using the trust game, an established paradigm to investigate trust behavior in both patient and healthy populations alike, controlling for risky decision making. Twenty patients suffering from PD diagnosed according to UK PDS Brain Bank criteria and twenty healthy controls (matched for age, gender, education, and income) were recruited. We excluded those suffering from clinically relevant neuropsychiatric comorbidities.
  
  
  RESULTS
  We found that PD patients exhibit significantly lower levels of trust than do healthy controls. Importantly, our results cannot be explained by lower levels of risk-taking. Moreover, our results indicate that the trust deficit is independent of medication, disease duration, and severity of motor symptoms.
  
  
  CONCLUSIONS
  Application of a standard procedure for measuring trust behavior revealed that PD patients exhibit lower levels of trust in other humans than do healthy controls. Against this background we make a call for further research to determine the underlying pathophysiology of reduced trust in PD.
authors.affiliation: Department of Neurology and Psychiatry, Linz General Hospital, Faculty of Medicine, Johannes Kepler University Linz, Krankenhausstrasse 9, 4021, Linz, Austria. javor@gmx.at.
authors.forename: Andrija
authors.initials: A
authors.lastname: Javor
authors.affiliation: School of Management, University of Applied Sciences Upper Austria, Wehrgrabengasse 1-3, 4400, Steyr, Austria. rene.riedl@fh-steyr.at.|Department of Business Informatics - Information Engineering, Johannes Kepler University Linz, Altenberger Strasse 69, 4040, Linz, Austria. rene.riedl@fh-steyr.at.
authors.forename: René
authors.initials: R
authors.lastname: Riedl
authors.affiliation: Department of Neurology and Psychiatry, Linz General Hospital, Faculty of Medicine, Johannes Kepler University Linz, Krankenhausstrasse 9, 4021, Linz, Austria. matthias.kirchmayr@akh.linz.at.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kirchmayr
authors.affiliation: Department of Neurology and Psychiatry, Linz General Hospital, Faculty of Medicine, Johannes Kepler University Linz, Krankenhausstrasse 9, 4021, Linz, Austria. mirella.reichenberger@akh.linz.at.
authors.forename: Mirella
authors.initials: M
authors.lastname: Reichenberger
authors.affiliation: Department of Neurology and Psychiatry, Linz General Hospital, Faculty of Medicine, Johannes Kepler University Linz, Krankenhausstrasse 9, 4021, Linz, Austria. gerhard.ransmayr@akh.linz.at.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ransmayr
mesh_terms: D000368:Aged; D001479:Basal Ganglia / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000150:complications / Q000523:psychology; D003299:Cooperative Behavior; D003657:Decision Making; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D005717:Games, Experimental; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology*; D012201:Reward; D012306:Risk; D012309:Risk-Taking; D035502:Trust