Biermann K, Schmitz F, Witte O W, Konczak J, Freund H J, Schnitzler A
Department of Neurology, Heinrich-Heine University, Düsseldorf, Germany.
Neurosci Lett. 1998 Jul 17;251(1):13-6. doi: 10.1016/s0304-3940(98)00480-7.
Neuromagnetic responses to separate tactile stimulation of digits I, II and V and simultaneous stimulation of digit pairs II and I, and II and V, were recorded in six healthy adult subjects using a 122-channel whole-head neuromagnetometer in order to investigate functional overlap of finger representations in primary somatosensory cortex (SI). Evoked responses to single digit stimulation were explained by time-varying equivalent current dipoles (ECDs) located in SI. These ECDs were then used to explain responses to stimulation of digit pairs. A cortical interaction ratio (IR) was defined as the vector sum of peak source amplitudes to separate stimulations of two fingers divided by the vector sum of source amplitudes to simultaneous stimulation of the two digits. Mean IR was significantly higher (P<0.05; Wilcoxon test) for digit pair II + I (1.69+/- 0.15) compared to digit pair II + V (1.14+/- 0.12). These results indicate that there is an overlap of finger representations in human SI which differs between anatomically adjacent and non-adjacent digit pairs.
为了研究人类初级体感皮层（SI）中手指表征的功能重叠，使用122通道全脑磁强计记录了6名健康成年受试者对食指（I）、中指（II）和小指（V）单独触觉刺激以及对中指和食指、中指和小指成对刺激的神经磁反应。对单个手指刺激的诱发反应由位于SI的随时间变化的等效电流偶极子（ECD）解释。然后用这些ECD来解释对成对手指刺激的反应。皮质相互作用率（IR）定义为两个手指单独刺激时峰值源振幅的矢量和除以两个手指同时刺激时源振幅的矢量和。与II + V指对（1.14±0.12）相比，II + I指对的平均IR显著更高（P<0.05；Wilcoxon检验），为1.69±0.15。这些结果表明，人类SI中存在手指表征的重叠，且在解剖学上相邻和不相邻的指对之间存在差异。
