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Abstract：
Cognitive functions, such as learning and memory processes, depend on effective communication between brain regions which is facilitated by white matter tracts (WMT). We investigated the microstructural properties and the contribution of WMT to extinction learning and memory in a predictive learning task. Forty-two healthy participants completed an extinction learning paradigm without a fear component. We examined differences in microstructural properties using diffusion tensor imaging to identify underlying neural connectivity and structural correlates of extinction learning and their potential implications for the renewal effect. Participants with good acquisition performance exhibited higher fractional anisotropy (FA) in WMT including the bilateral inferior longitudinal fasciculus (ILF) and the right temporal part of the cingulum (CNG). This indicates enhanced connectivity and communication between brain regions relevant to learning and memory resulting in better learning performance. Our results suggest that successful acquisition and extinction performance were linked to enhanced structural connectivity. Lower radial diffusivity (RD) in the right ILF and right temporal part of the CNG was observed for participants with good acquisition learning performance. This observation suggests that learning difficulties associated with increased RD may potentially be due to less myelinated axons in relevant WMT. Also, participants with good acquisition performance were more likely to show a renewal effect. The results point towards a potential role of structural integrity in extinction-relevant WMT for acquisition and extinction.
摘要：
认知功能，比如学习和记忆过程，依赖于白质束（WMT）促进的大脑区域之间的有效交流。我们研究了预测学习任务中WMT的微观结构特性以及对灭绝学习和记忆的贡献。42名健康参与者在没有恐惧的情况下完成了灭绝学习范式。我们使用扩散张量成像检查了微观结构特性的差异，以确定灭绝学习的潜在神经连通性和结构相关性及其对更新效应的潜在影响。具有良好采集性能的参与者在WMT中表现出更高的各向异性分数（FA），包括双侧下纵束（ILF）和扣带的右颞部（CNG）。这表明与学习和记忆相关的大脑区域之间的连接和交流增强，从而提高学习性能。我们的结果表明，成功的捕获和灭绝性能与增强的结构连通性有关。对于具有良好习得学习表现的参与者，观察到右侧ILF和CNG右侧颞部的径向扩散系数（RD）较低。这一观察结果表明，与RD增加相关的学习困难可能是由于相关WMT中髓鞘轴突较少。此外，获得表现良好的参与者更有可能表现出更新效应。结果表明，结构完整性在与灭绝相关的WMT中对获取和灭绝具有潜在作用。
