Beisteiner Roland, Gartus Andreas, Erdler Marcus, Mayer Dagmar, Lanzenberger Rupert, Deecke Lüder
Department of Neurology, General Hospital and University of Vienna, Vienna, Austria.
Eur J Neurosci. 2004 Jan;19(2):465-72. doi: 10.1111/j.1460-9568.2004.03115.x.
The existence or non-existence of fine-scale motor somatotopy of the hand is a fundamental problem with regard to the functioning of the human brain. In contrast to seldom contradicted early twentieth century descriptions of activation overlap, descriptions of finger motor somatotopy faced disagreement. Recent blood-flow-related brain mapping data achieved with functional magnetic resonance imaging (fMRI) argue in favour of fine-scale somatotopy. However, considerable discrepancies between blood oxygen-level-dependent fMRI activations and intracortically recorded neuronal activity have been reported and it is unclear whether the blood flow results truly reflect the neuronal situation. We have used recent advances in magnetoencephalography to detect signals deriving directly from neuronal tissue. Besides replication of the overlap aspect, we found statistically significant evidence for the existence of a somatotopic aspect of human hand motor representation when comparing the fifth and first finger motor dipoles along the superior-inferior axis. The average location of the fifth finger was found to be 2.31 mm superior to the first finger.
手部精细运动躯体定位的存在与否是有关人类大脑功能的一个基本问题。与20世纪早期关于激活重叠的描述很少遭到反驳不同，手指运动躯体定位的描述存在分歧。最近通过功能磁共振成像（fMRI）获得的与血流相关的脑图谱数据支持精细躯体定位。然而，已经报道了血氧水平依赖性功能磁共振成像激活与皮层内记录的神经元活动之间存在相当大的差异，并且尚不清楚血流结果是否真的反映了神经元的情况。我们利用脑磁图的最新进展来检测直接源自神经元组织的信号。除了重复重叠方面的研究外，当沿着上下轴比较小指和食指运动偶极子时，我们发现了人类手部运动表征存在躯体定位方面的统计学显著证据。发现小指的平均位置比食指高2.31毫米。
