Centre de Recherche en Neuropsychologie et Cognition, University of Montreal, Montreal, Quebec H3C 3J7, Canada.
Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Verdun, Québec H4H 1R3, Canada.
Learn Mem. 2019 Mar 21;26(4):101-108. doi: 10.1101/lm.048306.118. Print 2019 Apr.
When people navigate, they use strategies dependent on one of two memory systems. The hippocampus-based spatial strategy consists of using multiple landmarks to create a cognitive map of the environment. In contrast, the caudate nucleus-based response strategy is based on the memorization of a series of turns. Importantly, response learners display more gray matter and functional activity in the caudate nucleus and less gray matter in the hippocampus. In parallel, the caudate nucleus is involved in decision-making by mediating attention toward rewards and in set-shifting by mediating preparatory actions. The present study, therefore, examined the link between navigational strategy use, that are associated with gray matter differences in the caudate nucleus and hippocampus, and decision-making and set-shifting performance. Fifty-three participants completed the 4 on 8 virtual maze, the Iowa Gambling Task (IGT), the Wisconsin Card Sorting Test-64 (WCST-64), and a task-switching test. The results revealed that people who use response strategies displayed increased risk-taking behavior in the IGT compared to the people using hippocampus-dependent spatial strategies. Response strategy was also associated with enhanced set-shifting performance in the WCST-64 and task-switching test. These results confirm that risk-taking and set-shifting behavior, that are differentially impacted by the caudate nucleus and hippocampus memory systems, can be predicted by navigational strategy.
当人们进行导航时，他们会使用依赖于两种记忆系统之一的策略。基于海马体的空间策略包括使用多个地标来创建环境的认知地图。相比之下，基于尾状核的反应策略则基于对一系列转弯的记忆。重要的是，反应学习者在尾状核中显示出更多的灰质和功能性活动，而在海马体中则显示出较少的灰质。平行地，尾状核通过介导对奖励的注意力和通过介导预备动作来调节转换。因此，本研究考察了导航策略的使用与尾状核和海马体灰质差异之间的联系，以及决策和转换行为之间的联系。53 名参与者完成了 4 个 8 虚拟迷宫、爱荷华赌博任务（IGT）、威斯康星卡片分类测试-64（WCST-64）和任务转换测试。结果表明，与使用海马体依赖空间策略的人相比，使用反应策略的人在 IGT 中表现出更高的冒险行为。反应策略还与 WCST-64 和任务转换测试中的转换行为增强有关。这些结果证实，冒险行为和转换行为受到尾状核和海马体记忆系统的不同影响，可以通过导航策略来预测。
