Al-Zahli Narjes, Aly Mariam, Baldassano Christopher
Department of Psychology, University of California, Berkeley; Berkeley, CA, USA.
Department of Psychology, Columbia University; New York, NY, USA.
bioRxiv. 2025 Sep 1:2025.08.27.672403. doi: 10.1101/2025.08.27.672403.
Many experiences occur repeatedly throughout our lives: we might watch the same movie more than once and listen to the same song on repeat. How does the brain modify its representations of events when experiences are repeated? We hypothesized that, with repeated viewing of a narrative movie, brain regions would adapt their event representations by becoming either finer (more detailed) or coarser (more generalized). To test this hypothesis, we analyzed data from 30 human participants who underwent functional magnetic resonance imaging (fMRI) while watching three 90-second clips from "The Grand Budapest Hotel" six times each. We used hidden Markov models and pattern similarity analysis applied to searchlights across the brain to quantify the strength of event structure at different timescales for each clip presentation. We then tested how event structure strength changed at both slow and fast timescales with repeated viewings. Most brain regions exhibited stability in the strength of event structure at both slow and fast timescales. Other regions, however, showed flexible event representations that became more or less granular across repeated clip presentations. Notably, several brain regions exhibited consistent changes in the strength of event structure at a slow timescale across different movie clips. Furthermore, in lateral occipital cortex and middle temporal gyrus, greater loss of event structure at a slow timescale predicted more detailed memory recall. These results highlight that event dynamics in the brain are not fixed, but can change flexibly with experience.
在我们的一生中，许多经历会反复出现：我们可能不止一次地观看同一部电影，反复聆听同一首歌曲。当经历重复时，大脑是如何改变其对事件的表征的呢？我们假设，随着对叙事电影的反复观看，大脑区域会通过变得更精细（更详细）或更粗糙（更笼统）来调整其对事件的表征。为了验证这一假设，我们分析了30名人类参与者的数据，这些参与者在观看《布达佩斯大饭店》的三个90秒片段各六次的过程中接受了功能磁共振成像（fMRI）扫描。我们使用隐藏马尔可夫模型和应用于全脑搜索光的模式相似性分析，来量化每个片段呈现时不同时间尺度下事件结构的强度。然后，我们测试了随着反复观看，事件结构强度在慢速和快速时间尺度上是如何变化的。大多数脑区在慢速和快速时间尺度上的事件结构强度都表现出稳定性。然而，其他区域则表现出灵活的事件表征，在反复的片段呈现过程中变得或多或少更具颗粒性。值得注意的是，几个脑区在不同电影片段的慢速时间尺度上，事件结构强度呈现出一致的变化。此外，在枕外侧皮层和颞中回，慢速时间尺度上事件结构的更大损失预示着更详细的记忆回忆。这些结果突出表明，大脑中的事件动态并非固定不变，而是会随着经验灵活变化。
