Generalizing experiences to guide decision-making in novel situations is a hallmark of flexible behavior. Cognitive maps of an environment or task can theoretically afford such flexibility, but direct evidence has proven elusive. In this study, we found that discretely sampled abstract relationships between entities in an unseen two-dimensional social hierarchy are reconstructed into a unitary two-dimensional cognitive map in the hippocampus and entorhinal cortex. We further show that humans use a grid-like code in entorhinal cortex and medial prefrontal cortex for inferred direct trajectories between entities in the reconstructed abstract space during discrete decisions. These grid-like representations in the entorhinal cortex are associated with decision value computations in the medial prefrontal cortex and temporoparietal junction. Collectively, these findings show that grid-like representations are used by the human brain to infer novel solutions, even in abstract and discrete problems, and suggest a general mechanism underpinning flexible decision-making and generalization.

概括经验以指导新情况下的决策是灵活行为的标志。理论上，环境或任务的认知地图可以提供这种灵活性，但事实证明直接证据难以捉摸。在这项研究中，我们发现在一个看不见的二维社会等级中实体之间的离散采样抽象关系被重建为海马体和内嗅皮质中的单一二维认知图。我们进一步表明，人类在离散决策期间使用内嗅皮层和内侧前额叶皮层中的类似网格的代码来推断重建抽象空间中实体之间的直接轨迹。内嗅皮层中的这些网格状表示与内侧前额叶皮层和颞顶叶交界处的决策值计算有关。