While recalling life events, we reexperience events of different durations, ranging across varying temporal scales, from several minutes to years. However, the brain mechanisms underlying temporal cognition are usually investigated only in small-scale periods—milliseconds to minutes. Are the same neurocognitive systems used to organize memory at different temporal scales? Here, we asked participants to compare temporal distances (time elapsed since event) to personal events at four different temporal scales (hour, day, week, and month) under fMRI. Cortical activity showed temporal scale sensitivity at the medial and lateral parts of the parietal lobe, bilaterally. Activity at the medial parietal cortex also showed a gradual progression from large- to small-scale processing, along a posterior–anterior axis. Interestingly, no sensitivity was found along the hippocampal long axis. In the medial scale-sensitive region, most of the voxels were preferentially active for the larger scale (month), and in the lateral region, scale selectivity was higher for the smallest scale (hour). These results demonstrate how scale-selective activity characterizes autobiographical memory processing and may provide a basis for understanding how the human brain processes and integrates experiences across timescales in a hierarchical manner.

在回忆生活事件的同时，我们重新体验不同持续时间的事件，范围跨越不同的时间尺度，从几分钟到几年不等。然而，时间认知背后的大脑机制通常只在小范围内进行研究——几毫秒到几分钟。是否使用相同的神经认知系统来组织不同时间尺度的记忆？在这里，我们要求参与者在 fMRI 下在四种不同的时间尺度（小时、天、周和月）上比较时间距离（自事件起经过的时间）与个人事件。皮质活动显示双侧顶叶内侧和外侧的时间尺度敏感性。内侧顶叶皮层的活动也显示出沿着后-前轴从大尺度处理到小尺度处理的逐渐进展。有趣的是，沿海马长轴未发现敏感性。在内侧尺度敏感区域，大部分体素对较大尺度（月）优先活跃，在外侧区域，尺度选择性对最小尺度（小时）较高。这些结果证明了尺度选择性活动如何表征自传体记忆处理，并可能为理解人类大脑如何以分层方式跨时间尺度处理和整合经验提供基础。