Institute of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
Peking University School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Beijing 100871, China.
Science. 2022 Feb 11;375(6581):632-639. doi: 10.1126/science.abm0204. Epub 2022 Feb 10.
How the brain stores a sequence in memory remains largely unknown. We investigated the neural code underlying sequence working memory using two-photon calcium imaging to record thousands of neurons in the prefrontal cortex of macaque monkeys memorizing and then reproducing a sequence of locations after a delay. We discovered a regular geometrical organization: The high-dimensional neural state space during the delay could be decomposed into a sum of low-dimensional subspaces, each storing the spatial location at a given ordinal rank, which could be generalized to novel sequences and explain monkey behavior. The rank subspaces were distributed across large overlapping neural groups, and the integration of ordinal and spatial information occurred at the collective level rather than within single neurons. Thus, a simple representational geometry underlies sequence working memory.
大脑如何在记忆中存储序列在很大程度上仍是未知的。我们使用双光子钙成像技术来记录猕猴前额皮质中数千个神经元，在延迟后记忆和再现序列的位置，以此来研究序列工作记忆的神经编码。我们发现了一种规则的几何结构：延迟过程中的高维神经状态空间可以分解为低维子空间的和，每个子空间存储给定顺序等级的空间位置，可以推广到新的序列并解释猴子的行为。等级子空间分布在大的重叠神经元组中，顺序和空间信息的整合是在集体层面上发生的，而不是在单个神经元中。因此，序列工作记忆的基础是一种简单的表示几何结构。
