美国加州大学洛杉矶分校Itzhak Fried等研究人员合作发现，人类海马和内嗅皮层神经元编码体验的时间结构。相关论文于2024年9月25日在线发表在《自然》杂志上。

研究人员记录了因临床原因植入颅内电极的个体的单个神经元，展示了人类海马和内嗅皮层神经元逐渐调整其活动，以编码复杂图像呈现序列的时间结构。这一表征迅速形成，未向参与者提供具体指示，且在规定体验不再存在时仍持续存在。此外，从海马-内嗅皮层神经元的群体活动中恢复的结构与定义序列的结构图密切相似，同时也反映了即将出现刺激的概率。最后，序列图的学习与对应于先前经历的图轨迹的个体神经元活动的自发、时间压缩重放相关。

这些发现表明，海马和内嗅皮层的神经元整合了“什么”和“何时”信息，以提取人类体验的时间结构的持久和预测性表征。

据悉，提取体验的潜在时间结构是学习和记忆的基本方面，使我们能够预测接下来可能发生的事情。当前关于这一认知过程在人体内神经基础的知识主要来源于功能性神经成像研究。由于这些方法无法直接接触神经元层面，关于人脑中这一过程如何由神经元计算仍不清楚。

附：英文原文

Title: Human hippocampal and entorhinal neurons encode the temporal structure of experience

Author: Tacikowski, Pawel, Kalender, Gldamla, Ciliberti, Davide, Fried, Itzhak

Issue&Volume: 2024-09-25

Abstract: Extracting the underlying temporal structure of experience is a fundamental aspect of learning and memory that allows us to predict what is likely to happen next. Current knowledge about the neural underpinnings of this cognitive process in humans stems from functional neuroimaging research1,2,3,4,5. As these methods lack direct access to the neuronal level, it remains unknown how this process is computed by neurons in the human brain. Here we record from single neurons in individuals who have been implanted with intracranial electrodes for clinical reasons, and show that human hippocampal and entorhinal neurons gradually modify their activity to encode the temporal structure of a complex image presentation sequence. This representation was formed rapidly, without providing specific instructions to the participants, and persisted when the prescribed experience was no longer present. Furthermore, the structure recovered from the population activity of hippocampal–entorhinal neurons closely resembled the structural graph defining the sequence, but at the same time, also reflected the probability of upcoming stimuli. Finally, learning of the sequence graph was related to spontaneous, time-compressed replay of individual neurons’ activity corresponding to previously experienced graph trajectories. These findings demonstrate that neurons in the hippocampus and entorhinal cortex integrate the ‘what’ and ‘when’ information to extract durable and predictive representations of the temporal structure of human experience.

DOI: 10.1038/s41586-024-07973-1

Source: https://www.nature.com/articles/s41586-024-07973-1