Stress-induced shift from declarative to procedural learning; interindividual differences and neuronal mechanisms

压力体验不仅影响单个记忆系统的数量表现，而且还影响多个不同的、解剖和功能不同的系统对学习和记忆的相对贡献。特别是，最近的证据表明，在双重解决方案任务中，压力促进了从陈述性、目标导向的记忆过程向程序性、习惯性记忆过程的转变。然而，并不是所有的人在压力后都表现出从陈述性学习到程序性学习的转变，问题是哪些因素导致了这些个体间的差异。这个问题特别令人感兴趣，因为从陈述性记忆到程序性记忆的转变被认为在压力相关的精神障碍中起到了一定作用。在这项研究中，磁共振成像将与行为遗传学、认知和差异心理学方法相结合，以确定导致压力对使用多种记忆系统的影响的个体间差异的影响，并检查参与这些影响的大脑过程。这里，重点将放在编码α2肾上腺素能受体的基因ADRA2B上。人们预计，该基因的一个常见变体可能会在杏仁核活动增加的介导下，增强应激后向更多程序性学习的转变。除了它们与基础科学的相关性外，本项目的结果还可能具有一些重要的临床意义。

Stressful experiences affect not only the quantitative performance of a single memory system, but also the relative contributions of multiple, anatomically and functionally distinct systems to learning and memory. In particular, recent evidence shows that stress promotes in dual-solution tasks a shift from declarative, goal-directed memory processes to procedural, habitual memory processes. However, not all individuals show this shift from declarative to procedural learning after stress and the question is which factors are responsible for these interindividual differences. This question is of particular interest because the shift from declarative to procedural memory has been suggested to play a part in stress-related psychiatric disorders. In the present study, magnetic resonance imaging will be combined with behavioral genetics, cognitive and differential psychological approaches to identify influences contributing to the interindividual differences in the effects of stress on the use of multiple memory systems and to examine the brain processes involved in these influences. Here, the focus will be on ADRA2B, the gene encoding the alpha2-adrenergic receptor. It is expected that a common variant of this gene may, mediated by increased amygdala activity, augment the shift towards more procedural learning after stress. Beyond their relevance for basic science, the results of the present project may also have some important clinical implications.