School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China.
Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
Cereb Cortex. 2021 Aug 26;31(10):4427-4438. doi: 10.1093/cercor/bhab097.
Somatotopy is an important guiding principle for sensory fiber organization in the primary somatosensory cortex (S1), which reflects tactile information processing and is associated with disease-related reorganization. However, it is difficult to measure the neuronal encoding scheme in S1 in vivo in normal participants. Here, we investigated the somatotopic map of the undominant hand using a Bayesian population receptive field (pRF) model. The model was established in hand space with between- and within-digit dimensions. In the between-digit dimension, orderly representation was found, which had low variability across participants. The pRF shape tended to be elliptical for digits with high spatial acuity, for which the long axis was along the within-digit dimension. In addition, the pRF width showed different change trends in the 2 dimensions across digits. These results provide new insights into the neural mechanisms in S1, allowing for in-depth investigation of somatosensory information processing and disease-related reorganization.
躯体定位是初级体感皮层（S1）中感觉纤维组织的重要指导原则，它反映了触觉信息处理，并与与疾病相关的重组有关。然而，在正常参与者中，很难在体内测量 S1 中的神经元编码方案。在这里，我们使用贝叶斯群体感受野（pRF）模型研究了非优势手的躯体定位图。该模型是在手空间中建立的，具有手指间和手指内维度。在手指间维度中，发现了有序的表示，其在参与者之间的变异性较低。对于具有高空间灵敏度的数字，pRF 形状趋于椭圆形，其长轴沿手指内维度。此外，pRF 宽度在不同数字的两个维度上表现出不同的变化趋势。这些结果为 S1 中的神经机制提供了新的见解，使深入研究体感信息处理和与疾病相关的重组成为可能。
