title: Medically unexplained symptom reports are associated with a decreased response to the rubber hand illusion.
abstract: OBJECTIVE
  Medically unexplained symptoms (MUS) have been hypothesized to result from a distortion in perception, whereby top-down factors influence the process of body representation. Perceptual illusions provide a novel method of investigating this hypothesis. This study aimed to investigate whether self-reported unexplained symptoms are associated with altered experience of the rubber hand illusion (RHI).
  
  
  METHODS
  A non-clinical MUS group with high scores on the Somatoform Dissociation Questionnaire (SDQ), and a control group with low scores on this scale, were exposed to the RHI. Illusion experience was measured by self-reports and by proprioceptive alteration.
  
  
  RESULTS
  After controlling for somatosensory amplification and trait anxiety, the low-SDQ group responded significantly more strongly to the RHI on both questionnaire and proprioceptive measures of the illusion. In contrast, the high-SDQ group scored significantly higher on the Perceptual Aberrations Scale, a measure of bodily distortions in daily life.
  
  
  CONCLUSIONS
  These findings support the proposed link between MUS and disturbances in body representation, and suggest that a decreased reliance on current sensory inputs may contribute to symptom experience in susceptible individuals.
authors.affiliation: School of Psychological Sciences, University of Manchester, Manchester, M13 9PL, United Kingdom. e.miles@sheffield.ac.uk
authors.forename: Eleanor
authors.initials: E
authors.lastname: Miles
authors.forename: Ellen
authors.initials: E
authors.lastname: Poliakoff
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Brown
mesh_terms: D000328:Adult; D001007:Anxiety / Q000503:physiopathology; D001828:Body Image; D005260:Female; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D010468:Perceptual Disorders / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology; D013001:Somatoform Disorders / Q000503:physiopathology*; D014110:Touch / Q000502:physiology; D055698:Touch Perception / Q000502:physiology*