A functional role of the cerebral cortex is to form and hold representations of the sensory world for behavioral purposes. This is achieved by a sheet of neurons, organized in modules called cortical columns, that receives inputs in a peculiar manner, with only a few neurons driven by sensory inputs through thalamic projections, and a vast majority of neurons receiving mainly cortical inputs. How should cortical modules be organized, with respect to sensory inputs, in order for the cortex to efficiently hold sensory representations in memory? To address this question we investigate the memory performance of trees of recurrent networks (TRN) that are composed of recurrent networks, modeling cortical columns, connected with each others through a tree-shaped feed-forward backbone of connections, with sensory stimuli injected at the root of the tree. On these sensory architectures two types of short-term memory (STM) mechanisms can be implemented, STM via transient dynamics on the feed-forward tree, and STM via reverberating activity on the recurrent connectivity inside modules. We derive equations describing the dynamics of such networks, which allow us to thoroughly explore the space of possible architectures and quantify their memory performance. By varying the divergence ratio of the tree, we show that serial architectures, where sensory inputs are successively processed in different modules, are better suited to implement STM via transient dynamics, while parallel architectures, where sensory inputs are simultaneously processed by all modules, are better suited to implement STM via reverberating dynamics.

中文翻译：

---

感觉神经体系结构的短期记忆特性。

大脑皮层的功能性作用是出于行为目的形成并保持感觉世界的表征。这是通过以称为皮质列的模块组织的一组神经元来实现的，该神经元以特殊的方式接收输入，只有少数神经元由丘脑投射的感觉输入驱动，而绝大多数神经元主要接收皮质输入。关于感觉输入，应该如何组织皮质模块，以使皮质有效地将感觉表示保存在内存中？为了解决这个问题，我们研究了循环网络（TRN）的记忆性能，该循环网络由循环网络组成，对皮质柱进行建模，并通过树形前馈主干相互连接，并在树突处注入感觉刺激。树的根。在这些感觉体系结构上，可以实现两种类型的短期记忆（STM）机制，STM通过前馈树上的瞬态动力学，而STM通过回响活动来实现模块内部的周期性连接。我们导出描述此类网络动态性的方程式，这些方程式使我们能够彻底探索可能的体系结构的空间并量化其内存性能。通过改变树的发散比，我们表明，串行结构的传感输入在不同的模块中被连续处理，更适合于通过瞬态动力学实现STM，而并行结构的传感输入由所有模块同时处理。更适合通过回响动力学实现STM。