van Gerven Dustin J H, Ferguson Thomas, Skelton Ronald W
Department of Psychology, University of Victoria, Canada.
Department of Psychology, University of Victoria, Canada.
Neurobiol Learn Mem. 2016 Jul;132:29-39. doi: 10.1016/j.nlm.2016.05.003. Epub 2016 May 9.
Stress and stress hormones are known to influence the function of the hippocampus, a brain structure critical for cognitive-map-based, allocentric spatial navigation. The caudate nucleus, a brain structure critical for stimulus-response-based, egocentric navigation, is not as sensitive to stress. Evidence for this comes from rodent studies, which show that acute stress or stress hormones impair allocentric, but not egocentric navigation. However, there have been few studies investigating the effect of acute stress on human spatial navigation, and the results of these have been equivocal. To date, no study has investigated whether acute stress can shift human navigational strategy selection between allocentric and egocentric navigation. The present study investigated this question by exposing participants to an acute psychological stressor (the Paced Auditory Serial Addition Task, PASAT), before testing navigational strategy selection in the Dual-Strategy Maze, a modified virtual Morris water maze. In the Dual-Strategy maze, participants can chose to navigate using a constellation of extra-maze cues (allocentrically) or using a single cue proximal to the goal platform (egocentrically). Surprisingly, PASAT stress biased participants to solve the maze allocentrically significantly more, rather than less, often. These findings have implications for understanding the effects of acute stress on cognitive function in general, and the function of the hippocampus in particular.
众所周知,压力和应激激素会影响海马体的功能,海马体是一种对基于认知地图的、以自我为中心的空间导航至关重要的脑结构。尾状核是一种对基于刺激反应的、以自我为中心的导航至关重要的脑结构,它对压力不太敏感。这一观点的证据来自啮齿动物研究,这些研究表明,急性应激或应激激素会损害以自我为中心的导航,但不会损害以自我为中心的导航。然而,很少有研究调查急性应激对人类空间导航的影响,而且这些研究的结果也模棱两可。迄今为止,尚无研究调查急性应激是否会改变人类在以自我为中心和以自我为中心的导航之间的导航策略选择。本研究通过让参与者暴露于急性心理应激源(节奏性听觉连续加法任务,PASAT)来调查这个问题,然后在双策略迷宫(一种改良的虚拟莫里斯水迷宫)中测试导航策略选择。在双策略迷宫中,参与者可以选择使用一系列迷宫外部线索(以自我为中心)或使用靠近目标平台的单个线索(以自我为中心)来导航。令人惊讶的是,PASAT压力使参与者更多地(而非更少地)选择以自我为中心的方式解决迷宫问题。这些发现对于理解急性应激对一般认知功能的影响,尤其是对海马体功能的影响具有重要意义。