Ahissar Ehud, Kleinfeld David
Department of Neurobiology, The Weizmann Institute of Science, Rehovot 76100, Israel.
Cereb Cortex. 2003 Jan;13(1):53-62. doi: 10.1093/cercor/13.1.53.
Two classes of neuronal architectures dominate in the ongoing debate on the nature of computing by nervous systems. The first is a predominantly feedforward architecture, in which local interactions among neurons within each processing stage play a less influential role compared with the drive of the input to that stage. The second class is a recurrent network architecture, in which the local interactions among neighboring neurons dominate the dynamics of neuronal activity so that the input acts only to bias or seed the state of the network. The study of sensorimotor networks, however, serves to highlight a third class of architectures, which is neither feedforward nor locally recurrent and where computations depend on large-scale feedback loops. Findings that have emerged from our laboratories and those of our colleagues suggest that the vibrissa sensorimotor system is involved in such closed-loop computations. In particular, single unit responses from vibrissa sensory and motor areas show generic signatures of phase-sensitive detection and control at the level of thalamocortical and corticocortical loops. These loops are likely to be components within a greater closed-loop vibrissa sensorimotor system, which optimizes sensory processing.
在当前关于神经系统计算本质的争论中，两类神经元架构占据主导地位。第一类主要是前馈架构，在每个处理阶段，与该阶段输入的驱动相比，神经元之间的局部相互作用发挥的影响较小。第二类是循环网络架构，其中相邻神经元之间的局部相互作用主导着神经元活动的动态变化，使得输入仅起到使网络状态产生偏差或作为其起始状态的作用。然而，对感觉运动网络的研究凸显了第三类架构，这类架构既不是前馈架构也不是局部循环架构，其计算依赖于大规模反馈回路。我们实验室以及我们同事实验室得出的研究结果表明，触须感觉运动系统参与了此类闭环计算。特别是，来自触须感觉和运动区域的单个单元反应在丘脑皮质和皮质皮质回路层面显示出相位敏感检测和控制的一般特征。这些回路可能是更大的闭环触须感觉运动系统的组成部分，该系统可优化感觉处理。
