Dowman R
Department of Psychology, Clarkson University, Potsdam, NY 13699-5825, USA.
Psychophysiology. 1996 May;33(3):252-61. doi: 10.1111/j.1469-8986.1996.tb00422.x.
This study attempted to replicate and extend earlier work that reported that the amplitude of the P200 peak of the human somatosensory evoked potential (SEP) can be increased and decreased when reward is made contingent upon change and that these changes are accompanied by alterations in pain sensitivity. Twenty-one subjects were able to make the amplitude of the P200 peak evoked by sural nerve stimulation larger during increased training (up-training) than during decreased training (down-training). There were no differences in the sural nerve compound action potential between up-training and down-training. This finding demonstrates that the change in P200 amplitude was not due to a change in stimulus efficacy, but rather to a change within the central nervous system. Subjective pain ratings and a nociceptive spinal reflex were the same in up-training as in down-training. Thus, conditioned changes in P200 amplitude do not alter pain sensitivity.
本研究试图重复并扩展早期的研究工作，早期研究报告称，当奖励取决于变化时，人类体感诱发电位（SEP）的P200峰的波幅可增大或减小，且这些变化伴随着疼痛敏感性的改变。21名受试者能够使腓肠神经刺激诱发的P200峰的波幅在增加训练（向上训练）期间比在减少训练（向下训练）期间更大。向上训练和向下训练期间腓肠神经复合动作电位没有差异。这一发现表明，P200波幅的变化不是由于刺激效果的改变，而是由于中枢神经系统内的变化。向上训练和向下训练时主观疼痛评分和伤害性脊髓反射相同。因此，P200波幅的条件性变化不会改变疼痛敏感性。
