title: Decision-making strategies by panic disorder subjects are more sensitive to errors.
abstract: BACKGROUND
  Decision-making is a complex process, which can be assessed experimentally by the two-choice prediction task. Error-rate, i.e. the frequency of incorrect predictions during this task, is an important factor for the response selection during decision-making. This investigation examined whether the frequency of incorrect predictions has an augmented effect on the number of different strategies underlying decision-making in patients with panic disorder.
  
  
  METHODS
  Patients with a DSM-IV diagnosis of panic disorder (PD; N=18), unipolar major depressive disorder (MDD; N=18) and normal comparison subjects (C; N=35) were tested with the two-choice prediction task using three error-rate conditions (20, 50, or 80%). The dynamical entropy of the response sequences was used to quantify the number of different strategies generated during the different error-rates.
  
  
  RESULTS
  At 20% error-rates, panic disorder subjects when compared to MDD and C subjects generated more strategies and switched more frequently between strategies as measured by the dynamical entropy and the range of local dynamical entropies. Response bias measures during the two-choice prediction task and post-test self-assessment did not differ between panic disorder subjects and MDD or C subjects.
  
  
  CONCLUSIONS
  First, panic disorder subjects were medicated. Second, the frequency and intensity of panic attacks and the degree of avoidance behaviors, was not assessed. Third, subjects were tested once only.
  
  
  CONCLUSIONS
  Panic disorder subjects show uniformly high response sequence unpredictability in the presence of low error-rates, which is consistent with continued search for an optimal response strategy even when the error-rate is low.
authors.affiliation: Psychiatric University Hospital Zurich, Lenggstrasse 31, CH-8029 Zurich, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Ludewig
authors.forename: Martin P
authors.initials: MP
authors.lastname: Paulus
authors.forename: Katja
authors.initials: K
authors.lastname: Ludewig
authors.forename: Franz X
authors.initials: FX
authors.lastname: Vollenweider
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000523:psychology*; D003657:Decision Making; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000523:psychology*; D012054:Reinforcement, Psychology; D013647:Task Performance and Analysis