Wood C C, Cohen D, Cuffin B N, Yarita M, Allison T
Science. 1985 Mar 1;227(4690):1051-3. doi: 10.1126/science.3975600.
Magnetic fields and electrical potentials produced by neuronal activity have different properties that can be used for the identification of electrical sources in the human brain. Fields and potentials occurring 20 to 30 milliseconds after median nerve stimulation in human subjects were compared in order to investigate the sources of evoked potential components that have been attributed by different investigators to the thalamus or thalamocortical afferents, to separate radial sources in somatosensory cortex and motor cortex, or to a tangential source in somatosensory cortex. The magnetic and potential wave forms were highly similar in morphology, and their spatial distributions were centered over sensorimotor cortex, were dipolar in shape, and differed in orientation by approximately 90 degrees; distances between the minimum and maximum of the magnetic distributions were about 60 percent of those of the potential distributions. These results cannot be accounted for by thalamic sources or radial cortical sources alone, but are consistent with a tangential source in somatosensory cortex, with an additional smaller contribution from radial sources.
神经元活动产生的磁场和电势具有不同特性，可用于识别人类大脑中的电信号源。为了研究不同研究者归因于丘脑或丘脑皮质传入神经的诱发电位成分的来源、区分体感皮层和运动皮层中的径向源或体感皮层中的切向源，对人类受试者正中神经刺激后20至30毫秒出现的场和电势进行了比较。磁场和电势波形在形态上高度相似，它们的空间分布以感觉运动皮层为中心，呈偶极形状，方向相差约90度；磁分布最小值和最大值之间的距离约为电势分布距离的60%。这些结果不能仅由丘脑源或径向皮质源来解释，而是与体感皮层中的切向源一致，同时径向源也有较小的额外贡献。
