Forss N, Salmelin R, Hari R
Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland.
Electroencephalogr Clin Neurophysiol. 1994 Nov;92(6):510-7. doi: 10.1016/0168-5597(94)90135-x.
We recorded somatosensory evoked magnetic fields (SEFs) from 6 healthy subjects with a 122-channel whole-scalp SQUID gradiometer. In separate experiments, airpuff stimuli were delivered to the dorsum of the proximal phalanx of the middle finger, and electric stimuli were delivered to the median nerve at the wrist; the interstimulus interval was 3 sec and left and right hands were stimulated in subsequent sessions. Airpuffs evoked clear and reproducible responses in all subjects. First responses were recorded over the SI cortex. All subjects showed SII responses both to contra- and ipsilateral airpuffs. The posterior parietal source, identified previously to electric stimulation, was activated also by airpuffs, but only in the right hemisphere. The earliest responses from SI were smaller in amplitude and longer in latency to airpuffs than to electric stimuli; the long-latency responses arising from the other somatosensory areas did not differ significantly.
我们使用122通道全头皮超导量子干涉仪梯度计记录了6名健康受试者的体感诱发磁场（SEF）。在单独的实验中，向中指近节指骨背侧施加吹气刺激，并向腕部正中神经施加电刺激；刺激间隔为3秒，在随后的实验中对左右手进行刺激。吹气在所有受试者中均诱发了清晰且可重复的反应。首次反应记录于初级体感皮层（SI）。所有受试者对同侧和对侧吹气均表现出次级体感皮层（SII）反应。先前确定对电刺激有反应的顶叶后皮质源，对吹气也有激活，但仅在右半球。来自SI的最早反应与电刺激相比，对吹气的反应幅度较小且潜伏期较长；来自其他体感区域的长潜伏期反应没有显著差异。
