Hu Sien, Li Chiang-Shan R
Department of Psychology, State University of New York at Oswego, Oswego, NY 13126, USA.
Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06519, USA.
Brain Sci. 2020 Dec 19;10(12):1013. doi: 10.3390/brainsci10121013.
Aging is associated with structural and functional changes in the hippocampus, and hippocampal dysfunction represents a risk marker of Alzheimer's disease. Previously, we demonstrated age-related changes in reactive and proactive control in the stop signal task, each quantified by the stop signal reaction time (SSRT) and sequential effect computed as the correlation between the estimated stop signal probability and go trial reaction time. Age was positively correlated with the SSRT, but not with the sequential effect. Here, we explored hippocampal gray matter volume (GMV) and activation to response inhibition and to p(Stop) in healthy adults 18 to 72 years of age. The results showed age-related reduction of right anterior hippocampal activation during stop success vs. go trials, and the hippocampal activities correlated negatively with the SSRT. In contrast, the right posterior hippocampus showed higher age-related responses to p(Stop), but the activities did not correlate with the sequential effect. Further, we observed diminished GMVs of the anterior and posterior hippocampus. However, the GMVs were not related to behavioral performance or regional activities. Together, these findings suggest that hippocampal GMVs and regional activities represent distinct neural markers of cognitive aging, and distinguish the roles of the anterior and posterior hippocampus in age-related changes in cognitive control.
衰老与海马体的结构和功能变化相关，而海马体功能障碍是阿尔茨海默病的一个风险标志物。此前，我们在停止信号任务中证明了反应性和主动性控制方面与年龄相关的变化，分别通过停止信号反应时间（SSRT）以及作为估计停止信号概率与继续试验反应时间之间的相关性计算得出的序列效应来量化。年龄与SSRT呈正相关，但与序列效应无关。在此，我们研究了18至72岁健康成年人的海马体灰质体积（GMV）以及对反应抑制和p(Stop)的激活情况。结果显示，在停止成功与继续试验期间，右侧前海马体激活呈现与年龄相关的减少，并且海马体活动与SSRT呈负相关。相比之下，右侧后海马体对p(Stop)表现出更高的与年龄相关的反应，但这些活动与序列效应无关。此外，我们观察到前海马体和后海马体的GMV减少。然而，GMV与行为表现或区域活动无关。总之，这些发现表明海马体GMV和区域活动代表了认知衰老的不同神经标志物，并区分了前海马体和后海马体在与年龄相关的认知控制变化中的作用。
