title: Perceptual embodiment of prosthetic limbs by transcutaneous electrical nerve stimulation.
abstract: OBJECTIVE
  In able-bodied participants, it is possible to induce a sense of perceptual embodiment in an artificial hand using a visual-tactile illusion. In amputee patients, electrical stimulation of sensory afferents using transcutaneous electrical nerve stimulation (TENS) has been shown to generate somatic sensations in an amputee's phantom limb(s). However, the effects of TENS on the perceptual embodiment of an artificial limb are not known. Our objective was to investigate the effects of TENS on the perceptual embodiment of an artificial limb in fully intact able-bodied participants.
  
  
  METHODS
  We used a modified version of the rubber hand illusion presented to 30 able-bodied participants (16 women, 14 men) to convey TENS paresthesia to an artificial hand. TENS electrodes were located over superficial radial nerve on the lateral aspect of the right forearm (1 cm proximal to the wrist), which was hidden from view. TENS intensity was increased to a strong non-painful TENS sensation (electrical paresthesia) was felt beneath the electrodes and projecting into the fingers of the hand. The electrical characteristics of TENS were asymmetric biphasic electrical pulsed waves, continuous pulse pattern, 120 Hz pulse frequency (rate), and 80 µs pulse duration (width).
  
  
  RESULTS
  Participants reported significantly higher intensities of the rubber hand illusion during the two TENS conditions (mean = 5.8, standard deviation = 1.9) compared with the two non-TENS conditions (mean = 4.9, standard deviation = 1.7), p < 0.0005.
  
  
  CONCLUSIONS
  Our findings provide initial evidence that TENS paresthesia can be projected into an artificial limb, and this can enhance the sense of perceptual embodiment of an artificial hand. Further exploratory studies involving an amputee population are warranted.
authors.affiliation: Faculty of Health, Leeds Metropolitan University, Leeds, UK. m.mulvey@leedsmet.ac.uk
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Mulvey
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Fawkner
authors.forename: Helen E
authors.initials: HE
authors.lastname: Radford
authors.forename: Mark I
authors.initials: MI
authors.lastname: Johnson
mesh_terms: D000674:Amputees; D001186:Artificial Limbs; D005260:Female; D006801:Humans; D007088:Illusions; D008297:Male; D010465:Perception / Q000502:physiology*; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*