Abstract:
We investigated how the human brain integrates experiences of specific events to build general knowledge about typical event structure. We examined an episodic memory area important for temporal relations, anterior-lateral entorhinal cortex, and a semantic memory area important for action concepts, middle temporal gyrus, to understand how and when these areas contribute to these processes. Participants underwent functional magnetic resonance imaging while learning and recalling temporal relations among novel events over two sessions 1 week apart. Across distinct contexts, individual temporal relations among events could either be consistent or inconsistent with each other. Within each context, during the recall phase, we measured associative coding as the difference of multivoxel correlations among related vs unrelated pairs of events. Neural regions that form integrative representations should exhibit stronger associative coding in the consistent than the inconsistent contexts. We found evidence of integrative representations that emerged quickly in anterior-lateral entorhinal cortex (at session 1), and only subsequently in middle temporal gyrus, which showed a significant change across sessions. A complementary pattern of findings was seen with signatures during learning. This suggests that integrative representations are established early in anterior-lateral entorhinal cortex and may be a pathway to the later emergence of semantic knowledge in middle temporal gyrus.
摘要:
我们研究了人脑如何整合特定事件的经验,以建立有关典型事件结构的一般知识。我们检查了一个对时间关系很重要的情景记忆区域,前外侧内嗅皮层,和一个对动作概念很重要的语义记忆区,颞中回,了解这些领域如何以及何时对这些过程做出贡献。参与者进行了功能磁共振成像,同时学习和回顾了两个间隔1周的新事件之间的时间关系。在不同的背景下,事件之间的个体时间关系可以是一致的,也可以是不一致的。在每个上下文中,在召回阶段,我们将关联编码测量为相关事件对与无关事件对之间多体素相关性的差异。形成整合表示的神经区域在一致性中应表现出比不一致上下文更强的关联编码。我们发现了在前外侧内嗅皮层(在第1阶段)中迅速出现的整合表征的证据,随后仅在颞中回,这表明会议之间发生了重大变化。在学习过程中,发现了一种互补的发现模式。这表明整合表征在前外侧内嗅皮层的早期建立,并且可能是后来在中颞回出现语义知识的途径。