Graziano M S
Psychology Department, Green Hall, Princeton University, Princeton, NJ 08544-1010, USA.
Proc Natl Acad Sci U S A. 1999 Aug 31;96(18):10418-21. doi: 10.1073/pnas.96.18.10418.
A central problem in motor control, in the representation of space, and in the perception of body schema is how the brain encodes the relative positions of body parts. According to psychophysical studies, this sense of limb position depends heavily on vision. However, almost nothing is currently known about how the brain uses vision to determine or represent the location of the arm or any other body part. The present experiment shows that the position of the arm is represented in the premotor cortex of the monkey (Macaca fascicularis) brain by means of a convergence of visual cues and proprioceptive cues onto the same neurons. These neurons respond to the felt position of the arm when the arm is covered from view. They also respond in a similar fashion to the seen position of a false arm.
运动控制、空间表征以及身体图式感知中的一个核心问题是大脑如何编码身体各部分的相对位置。根据心理物理学研究，这种肢体位置感在很大程度上依赖于视觉。然而，目前对于大脑如何利用视觉来确定或表征手臂或任何其他身体部位的位置几乎一无所知。本实验表明，猴子（食蟹猴）大脑的运动前区皮层通过视觉线索和本体感受线索汇聚到同一神经元上的方式来表征手臂的位置。当手臂被遮挡而看不到时，这些神经元会对手臂的感觉位置做出反应。它们对假手臂的视觉位置也会以类似方式做出反应。
