Iwamura Y, Iriki A, Tanaka M
Department of Physiology, Toho University School of Medicine, Tokyo, Japan.
Nature. 1994 Jun 16;369(6481):554-6. doi: 10.1038/369554a0.
In accordance with its important role in prehensile activity, a large cortical area is devoted to representation of the digits. Within this large cortical zone in the macaque somatosensory cortex, the complexity of neuronal receptive field characteristics increases from area 3b to areas 1 and 2 (refs 1-7). This increase in complexity continues into the upper bank of the intraparietal sulcus, where the somatosensory cortex adjoins the parietal association cortex. In this bank, callosal connections are much denser than in the more anterior part of this cortical zone. We have now discovered a substantial number of neurons with receptive fields on the bilateral hands. It was previously thought that neuronal receptive fields were restricted to the contralateral side in this cortical zone. Neurons with bilateral receptive fields were not found after lesioning the postcentral gyrus in the contralateral hemisphere. The majority of these neurons had receptive fields of the most complex types, representing multiple digits, indicating that the interhemispheric transfer of information occurs at higher levels of the hierarchical processing in each hemisphere.
鉴于其在抓握活动中的重要作用，大量皮质区域专门用于表征手指。在猕猴体感皮质的这个大皮质区内，神经元感受野特征的复杂性从3b区向1区和2区递增（参考文献1 - 7）。这种复杂性的增加一直延续到顶内沟的上壁，此处体感皮质与顶叶联合皮质相邻。在这个脑区，胼胝体连接比该皮质区更靠前的部分密集得多。我们现在发现了大量感受野位于双侧手部的神经元。以前认为在这个皮质区内神经元感受野局限于对侧。在对侧半球中央后回损伤后未发现具有双侧感受野的神经元。这些神经元中的大多数具有最复杂类型的感受野，代表多个手指，这表明信息的半球间传递发生在每个半球层次处理的较高水平。
