Stress Modulates the Engagement of Multiple Memory Systems in Classification Learning
Stress Modulates the Engagement of Multiple Memory Systems in Classification Learning
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DOI：
10.1523/jneurosci.1484-12.2012
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发表时间：
2012-08
期刊：
影响因子：
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通讯作者：
L. Schwabe;O. Wolf
中科院分区：
文献类型：
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作者：
L. Schwabe;O. Wolf
学习和记忆是由解剖学上和功能上不同的系统支持的。最近的研究表明，压力可能会改变多个记忆系统对学习的贡献，但人类大脑中的潜在机制仍然完全未知。使用事件相关的功能磁共振成像，我们问在本实验中，压力是否可以调节参与的大脑皮层为基础的“陈述性”和纹状体为基础的“程序性”的记忆系统在人类的分类学习和什么样的大脑机制参与这种效果。我们发现，压力减少了关于学习任务的陈述性知识，并改变了使用的学习策略，从一个单一的线索为基础的陈述性策略，以多线索为基础的程序性策略，而学习成绩本身不受压力的影响。神经影像学显示，海马活动与控制条件下的任务表现呈正相关，而纹状体活动与应激条件下的表现相关。应激后海马活性降低，甚至与学习成绩呈负相关。这些发现首次表明，压力改变了人类大脑中多个记忆系统的参与。压力损害了纹状体依赖的系统，并允许纹状体控制行为。压力后向“程序性”学习的转变似乎可以挽救任务表现，而试图参与“陈述性”系统则会破坏表现。
Learning and memory are supported by anatomically and functionally distinct systems. Recent research suggests that stress may alter the contributions of multiple memory systems to learning, yet the underlying mechanism in the human brain remains completely unknown. Using event-related functional magnetic resonance imaging, we asked in the present experiment whether stress may modulate the engagement of hippocampus-based “declarative” and striatum-based “procedural” memory systems during classification learning in humans and what brain mechanisms are involved in this effect. We found that stress reduced declarative knowledge about the learning task and changed the used learning strategy from a single-cue-based declarative strategy to a multicue-based procedural strategy, whereas learning performance per se remained unaffected by stress. Neuroimaging revealed that hippocampal activity correlated positively with task performance in the control condition, whereas striatal activity correlated with performance in the stress condition. After stress, hippocampal activity was reduced and even negatively correlated with learning performance. These findings show for the first time that stress alters the engagement of multiple memory systems in the human brain. Stress impaired the hippocampus-dependent system and allowed the striatum to control behavior. The shift toward “procedural” learning after stress appears to rescue task performance, whereas attempts to engage the “declarative” system disrupt performance.