title: Distinguishing Feigned From Sincere Performance in Psychophysical Pain Testing.
abstract: Self-report, the most widely used, gold standard measurement of pain, is crucial for pain research, diagnosis, and management. However, there are no accurate, reliable methods for detecting dishonesty in self-reports when there is incentive for pain deception. We introduce a novel approach to detecting pain deception by analyzing performance patterns of honest and dishonest psychophysical pain testing. Warmth sensation threshold (WST) and heat pain threshold (HPT) were measured in healthy individuals (N = 37) under 2 conditions: standard instruction (ie, provide sincere reports) and instructions to simulate intense pain (i.e., provide feigned reports) with the intention of deceiving. In the feigned compared with sincere condition, participants had significantly increased WST and decreased HPT. Repeatability and variability indices were indistinguishable between conditions. In a second, separate cohort (N = 24), measurements were repeated with the addition of a sensory interference to influence task performance. When sensory interference during HPT measurement was introduced, feigned pain reports had significantly higher variability and poorer repeatability compared with sincere reports and were distinguishable from sincere reports, with high sensitivity (83%) and specificity (84%). The statistical properties of psychophysical performance under sensory interference provide a method for identifying feigned performance and could be applied to evaluations of pain malingering.
  
  
  CONCLUSIONS
  This article introduces a method to detect whether individuals are being dishonest in psychophysical pain testing. The method could help clinicians to detect chronic pain malingering in contexts in which there is incentive to deceive.
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Division of Brain, Imaging and Behaviour - Systems Neuroscience, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Kucyi
authors.affiliation: Department of Physical Therapy, Sackler Faculty of Medicine, and Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Aviv
authors.initials: A
authors.lastname: Scheinman
authors.affiliation: Department of Physical Therapy, Sackler Faculty of Medicine, and Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel. Electronic address: rutidef@post.tau.ac.il.
authors.forename: Ruth
authors.initials: R
authors.lastname: Defrin
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D008192:Deception; D004558:Electric Stimulation / Q000009:adverse effects; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000175:diagnosis; D008014:Lie Detection / Q000523:psychology*; D008297:Male; D010146:Pain / Q000175:diagnosis* / Q000523:psychology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology / Q000523:psychology; D011601:Psychophysics / Q000379:methods*; D012372:ROC Curve; D055815:Young Adult
keywords: Malingering; lie detection; pain psychophysics; sensory interference