Spinal Cord Injury Center, University Hospital Balgrist, University of Zurich, Zurich, Switzerland.
ICORD, University of British Columbia, Vancouver, BC, Canada.
Sci Rep. 2017 Jan 12;7:40007. doi: 10.1038/srep40007.
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.
“热格栅错觉”（TGI）是一种独特的不愉快皮肤感觉，通过交错应用温暖和凉爽的刺激来产生。虽然之前的研究已经调查了诱发这种错觉的最佳参数和受试者特征，但我们的目的是检查作为条件刺激的调节作用。共有 28 名健康对照者在不同的日子进行了三次测试。简而言之，将 15 个接触热刺激施加到手背，同时用中性（32°C）、凉爽（20°C）、温暖（40°C）或 TGI（20/40°C）对左手掌心进行条件刺激。评估感知评分（数字评分量表：0-10）和诱发电位（即，伤害性接触热刺激的 N1 和 N2P2 电位）。虽然凉爽和温暖的条件刺激降低了伤害性热刺激的皮质反应，但 TGI 条件刺激增加了诱发电位的幅度（N1 和 N2P2）。与不愉快条件刺激的其他模式（例如声音、视觉和嗅觉刺激）一致，皮质和可能的皮质下调节可能是接触热诱发电位促进的基础。
