Human hippocampal ripples predict the alignment of experience to a grid-like schema

作者：Zhibing Xiao, Xiongfei Wang, Jinbo Zhang, Jianxin Ou, Li He, Yukun Qu, Xiangyu Hu, Timothy E.J. Behrens, Yunzhe Liu · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2025 · DOI：10.1101/2025.01.08.632069 · 被引用次数：8 · 研究领域：Cognitive Science and Mapping、Identity, Memory, and Therapy、Paranormal Experiences and Beliefs

Humans create internal cognitive maps that allow us to make inferences beyond direct experience. These maps often rely on hexagonal grid-cell-like neural codes, serving as a schema for two-dimensional (2D) spaces. Yet it remains unclear how new experiences become aligned with this schema, especially in non-spatial contexts. Here, we show that hippocampal ripples - brief bursts of neuronal activity during rest - predict the emergence of grid-like codes in a novel 2D inference task. We recorded intracranial neuronal activity in 42 epilepsy patients as they learned rank relationships among feature objects (for example, objects differing in 'magic' or 'speed'). After learning, these objects were combined to form 'compounds' occupying a 2D conceptual space defined by two feature dimensions. During learning, hippocampal ripple activity increased during pauses between trials, suggesting that ripples integrated newly acquired information offline. Subsequently, ripple activity during post-learning rest predicted the later emergence of grid-like codes in the entorhinal cortex (EC) and medial prefrontal cortex (mPFC), a core region of the default mode network (DMN), when participants inferred unseen relationships among the compounds. Critically, coordination during rest between hippocampal ripples and DMN activity in the mPFC predicted participants' ability to infer complex relationships beyond direct memory retrieval. These findings provide the first direct evidence that hippocampal ri...