title: Set shifting and reversal learning in borderline personality disorder.
abstract: BACKGROUND
  People with BPD have been shown in some studies to have structural deficits in regions of the prefrontal cortex. A sensitive test of prefrontal cortex function is the intra-dimensional/extra-dimensional (IDED) set shifting task. This study sought to examine whether people with BPD demonstrate impaired performances on extra-dimensional shift (EDS) and reversal learning aspects of this task similar to those seen in conditions such as schizophrenia and bipolar affective disorder.
  
  
  METHODS
  Twenty subjects with BPD and 21 healthy control subjects were administered the IDED task from the Cambridge Neuropsychological Test Automated Battery cognitive test battery. EDS and reversal learning errors were compared between the groups using repeated measures ANOVAs.
  
  
  RESULTS
  There was no significant difference between the BPD and control participants in EDS or reversal learning on the IDED task or in stage of the task completed. There was a medium effect size difference (Cohen's d = 0.4) for simple reversal learning and small effect sizes for reversal learning (Cohen' d = 0.17) and IDED shift stages (Cohen's d = 0.2 and -0.3 respectively).
  
  
  CONCLUSIONS
  Participants with BPD in this study did not show statistically significant deficits in EDS or reversal learning, although small to medium effect sizes were found. These findings distinguish them from sufferers of schizophrenia and bipolar affective disorder and are in keeping with the idea that BPD is a distinct condition with discrete neuropathological processes.
authors.affiliation: Division of Psychiatry, Centre for Brain Sciences, School of Clinical Sciences, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Barker
authors.forename: Merrick
authors.initials: M
authors.lastname: Pope
authors.forename: Sharon
authors.initials: S
authors.lastname: Smith
authors.forename: Verity
authors.initials: V
authors.lastname: Brown
authors.forename: Jeremy
authors.initials: J
authors.lastname: Hall
mesh_terms: D000328:Adult; D001883:Borderline Personality Disorder / Q000523:psychology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012193:Reversal Learning; D012718:Set, Psychology; D055815:Young Adult