Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Denmark.
Eur J Pain. 2011 Sep;15(8):816-21. doi: 10.1016/j.ejpain.2011.01.015. Epub 2011 Mar 3.
The aim of the present study was to investigate supraspinal modulation of human lower limb reflex receptive fields (RRFs) on the plantar side of the foot during cognitive tasks either distracting the subjects or actively directing their attention to the electrical stimuli directed to the sole of the foot.
Twelve healthy volunteers participated. Nociceptive withdrawal reflexes (NWRs) were recorded in the ankle flexor tibialis anterior. The RRF was acquired by randomized activation of ten stimulation sites on the sole of the foot. The RRF was assessed during baseline, distraction, and attention in randomized order. Distraction was induced by the Stroop test, while attention was induced by requiring the subjects to localize the site of the stimulation and thereby forcing them to focus on the sole of the foot.
The area of the RRF was significantly enlarged during the distraction task compared to baseline (P<0.05), whereas the RRF area was significantly reduced during the attention task compared to baseline (P<0.05).
The size of the RRF area was modulated by the cognitive state demonstrating a link between the cognitive activity and the descending control on spinal withdrawal reflex pathways.
本研究旨在探讨认知任务对人体足部反射感受野（RRF）的脊髓上调制作用，这些认知任务要么分散受试者的注意力，要么主动引导他们注意足底的电刺激。
12 名健康志愿者参与了本研究。踝屈肌胫骨前肌的伤害性撤回反射（NWR）被记录下来。通过随机激活足底的十个刺激点来获取 RRF。RRF 在基线、分心和注意力三种状态下以随机顺序进行评估。分心通过 Stroop 测试来诱发，而注意力则通过要求受试者定位刺激部位来诱发，从而迫使他们专注于足底。
与基线相比，分心任务时 RRF 面积显著增大（P<0.05），而注意力任务时 RRF 面积显著减小（P<0.05）。
RRF 面积的大小受到认知状态的调制，表明认知活动与脊髓撤回反射通路的下行控制之间存在联系。
