Wanjia Guo, Han Subin, Kuhl Brice A
University of Oregon, Department of Psychology & Institute of Neuroscience.
University of Virginia, Department of Psychology.
bioRxiv. 2024 Oct 23:2024.10.23.619862. doi: 10.1101/2024.10.23.619862.
Recent human neuroimaging studies of episodic memory have revealed a counterintuitive phenomenon in the hippocampus: when events are highly similar, corresponding hippocampal activity patterns are sometimes less correlated than activity patterns associated with unrelated events. This phenomenon-is not accounted for by most theories of the hippocampus, and the conditions that trigger repulsion remain poorly understood. Here, we used a spatial route-learning task and high-resolution fMRI in humans to test whether hippocampal repulsion is fundamentally driven by internal beliefs about the environment. By precisely measuring participants' internal beliefs and actively manipulating them, we show that repulsion selectively occurred in hippocampal subfields CA3 and dentate gyrus when visual input was ambiguous-or even -but internal beliefs were distinct. These findings firmly establish conditions that elicit repulsion and have broad relevance to theories of hippocampal function and to the fields of human episodic memory and rodent spatial navigation.
当事件高度相似时，相应的海马体活动模式有时比与不相关事件相关的活动模式相关性更低。这种现象无法用大多数关于海马体的理论来解释，而且引发排斥反应的条件仍知之甚少。在此，我们利用人类的空间路径学习任务和高分辨率功能磁共振成像来测试海马体排斥反应是否从根本上由对环境的内在信念驱动。通过精确测量参与者的内在信念并积极加以操控，我们发现当视觉输入模糊不清甚至缺失但内在信念清晰时，排斥反应选择性地出现在海马体子区域CA3和齿状回中。这些发现明确了引发排斥反应的条件，并且与海马体功能理论以及人类情景记忆和啮齿动物空间导航领域密切相关。
