To memorize a sequence, one must serially bind each item to its rank order. How the brain controls a given input to bind its associated order in sequence working memory (SWM) remains unexplored. Here, we investigated the neural representations underlying SWM control using electrophysiological recordings in the frontal cortex of macaque monkeys performing forward and backward SWM tasks. Separate and generalizable low-dimensional subspaces for sensory and memory information were found within the same frontal circuitry, and SWM control was reflected in these neural subspaces’ organized dynamics. Each item at each rank was sequentially entered into a common sensory subspace and, depending on forward or backward task requirement, flexibly and timely sent into rank-selective SWM subspaces. Neural activity in these SWM subspaces faithfully predicted the recalled item and order information in single error trials. Thus, compositional neural population codes with well-orchestrated dynamics in frontal cortex support the flexible control of SWM.

中文翻译：

---

灵活控制猕猴额叶皮层中的序列工作记忆


要记住序列，必须将每个项目按顺序绑定到其等级顺序。大脑如何控制给定的输入以在序列工作记忆 （SWM） 中绑定其相关顺序仍未得到探索。在这里，我们使用执行前向和后向 SWM 任务的猕猴额叶皮层中的电生理记录研究了 SWM 控制背后的神经表示。在相同的额叶电路中发现了用于感觉和记忆信息的独立且可推广的低维子空间，并且 SWM 控制反映在这些神经子空间的组织动力学中。每个等级的每个项目都按顺序输入到一个共同的感觉子空间，并根据向前或向后的任务要求，灵活及时地发送到等级选择性的 SWM 子空间。这些 SWM 子空间中的神经活动忠实地预测了单错误试验中召回的项目和顺序信息。因此，额叶皮层中具有精心编排的动力学的组合神经种群代码支持 SWM 的灵活控制。