The Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
Department of Neuroscience, University of Geneva, Geneva, 1202, Switzerland.
Nat Commun. 2024 Jun 6;15(1):4815. doi: 10.1038/s41467-024-48648-9.
Our brain adeptly navigates goals across time frames, distinguishing between urgent needs and those of the past or future. The hippocampus is a region known for supporting mental time travel and organizing information along its longitudinal axis, transitioning from detailed posterior representations to generalized anterior ones. This study investigates the role of the hippocampus in distinguishing goals over time: whether the hippocampus encodes time regardless of detail or abstraction, and whether the hippocampus preferentially activates its anterior region for temporally distant goals (past and future) and its posterior region for immediate goals. We use a space-themed experiment with 7T functional MRI on 31 participants to examine how the hippocampus encodes the temporal distance of goals. During a simulated Mars mission, we find that the hippocampus tracks goals solely by temporal proximity. We show that past and future goals activate the left anterior hippocampus, while current goals engage the left posterior hippocampus. This suggests that the hippocampus maps goals using timestamps, extending its long axis system to include temporal goal organization.
我们的大脑能够熟练地在不同时间框架内导航目标,区分紧急需求与过去或未来的需求。海马体是一个已知的支持心理时间旅行的区域,能够沿着其纵轴组织信息,从详细的后部表示过渡到概括的前部表示。本研究调查了海马体在区分随时间变化的目标中的作用:海马体是否根据细节或抽象程度来编码时间,以及海马体是否优先为时间上遥远的目标(过去和未来)激活其前部区域,为即时目标激活其后部区域。我们使用一个以太空为主题的实验,在 31 名参与者中使用 7T 功能磁共振成像来研究海马体如何编码目标的时间距离。在模拟的火星任务中,我们发现海马体仅通过时间接近度来跟踪目标。我们表明,过去和未来的目标激活左侧前海马体,而当前的目标则激活左侧后海马体。这表明海马体使用时间戳来映射目标,将其长轴系统扩展到包括时间目标组织。