title: Thermal grill conditioning: Effect on contact heat evoked potentials.
abstract: The 'thermal grill illusion' (TGI) is a unique cutaneous sensation of unpleasantness, induced through the application of interlacing warm and cool stimuli. While previous studies have investigated optimal parameters and subject characteristics to evoke the illusion, our aim was to examine the modulating effect as a conditioning stimulus. A total of 28 healthy control individuals underwent three testing sessions on separate days. Briefly, 15 contact heat stimuli were delivered to the right hand dorsum, while the left palmar side of the hand was being conditioned with either neutral (32 °C), cool (20 °C), warm (40 °C), or TGI (20/40 °C). Rating of perception (numeric rating scale: 0-10) and evoked potentials (i.e., N1 and N2P2 potentials) to noxious contact heat stimuli were assessed. While cool and warm conditioning decreased cortical responses to noxious heat, TGI conditioning increased evoked potential amplitude (N1 and N2P2). In line with other modalities of unpleasant conditioning (e.g., sound, visual, and olfactory stimulation), cortical and possibly sub-cortical modulation may underlie the facilitation of contact heat evoked potentials.
authors.affiliation: Spinal Cord Injury Center, University Hospital Balgrist, University of Zurich, Zurich, Switzerland.|ICORD, University of British Columbia, Vancouver, BC, Canada.|School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Jutzeler
authors.affiliation: Spinal Cord Injury Center, University Hospital Balgrist, University of Zurich, Zurich, Switzerland.|ICORD, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Freda M
authors.initials: FM
authors.lastname: Warner
authors.affiliation: Spinal Cord Injury Center, University Hospital Balgrist, University of Zurich, Zurich, Switzerland.
authors.forename: Johann
authors.initials: J
authors.lastname: Wanek
authors.affiliation: Spinal Cord Injury Center, University Hospital Balgrist, University of Zurich, Zurich, Switzerland.
authors.forename: Armin
authors.initials: A
authors.lastname: Curt
authors.affiliation: ICORD, University of British Columbia, Vancouver, BC, Canada.|School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: John L K
authors.initials: JL
authors.lastname: Kramer
mesh_terms: D000293:Adolescent; D000328:Adult; D055664:Electrochemical Techniques; D004566:Electrodes; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D012684:Sensory Thresholds / Q000502:physiology; D013696:Temperature; D055815:Young Adult