A model of reaching dynamics in primary motor cortex.
A model of reaching dynamics in primary motor cortex.
复制标题
初级运动皮层到达动力学的模型。
DOI：
10.1162/089892998563761
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Zipser,D
中科院分区：
文献类型：
--
作者：
Moody,SL;Zipser,D
几乎所有随意运动的特征都在初级运动皮层中体现。这些运动可以是正在进行的、即将发生的、延迟的或想象的。我们的目标是研究运动皮层运动表征的动力学。为此，我们训练了一个完全循环的神经网络，以不断输出达到随机变化目标所需的运动方向和幅度。模型神经元发展出与真实运动皮层神经元相似的首选方向和其他特性。关键发现是，当到达运动的目标改变位置时，运动的整体表示几乎单调变化，并且构成表示的各个神经元表现出强烈的非单调瞬态。这些瞬变充当内部循环信号，迫使整体表示比受单个神经元时间常数限制的情况变化得更快。这些瞬变（如果存在）可以在实验中观察到，只需要对用于研究运动皮层运动表征的标准范式进行轻微修改即可。
Features of virtually all voluntary movements are represented in the primary motor cortex. The movements can be ongoing, imminent, delayed, or imagined. Our goal was to investigate the dynamics of movement representation in the motor cortex. To do this we trained a fully recurrent neural network to continually output the direction and magnitude of movements required to reach randomly changing targets. Model neurons developed preferred directions and other properties similar to real motor cortical neurons. The key finding is that when the target for a reaching movement changes location, the ensemble representation of the movement changes nearly monotonically, and the individual neurons comprising the representation exhibit strong, nonmonotonic transients. These transients serve as internal recurrent signals that force the ensemble representation to change more rapidly than if it were limited by the time constants of individual neurons. These transients, if they exist, could be observed in experiments that require only slight modifications of the standard paradigm used to investigate movement representation in the motor cortex.