Toepper Max, Markowitsch Hans J, Gebhardt Helge, Beblo Thomas, Bauer Eva, Woermann Friedrich G, Driessen Martin, Sammer Gebhard
Ev. Hospital Bielefeld (EvKB), Department of Psychiatry and Psychotherapy Bethel, Research Department, Remterweg 69-71, D-33617 Bielefeld, Germany; Justus-Liebig-University of Giessen, Cognitive Neuroscience at Centre for Psychiatry (CNS@ZPG), Am Steg 28, D-35392 Giessen, Germany.
University of Bielefeld, Department of Psychology, Universitätsstraße 25, D-33615 Bielefeld, Germany.
Neuropsychologia. 2014 Jul;59:157-68. doi: 10.1016/j.neuropsychologia.2014.04.020. Epub 2014 May 10.
Healthy aging is accompanied by a decline in spatial working memory that is related to functional cerebral changes within the spatial working memory network. In the last decade, important findings were presented concerning the location (e.g., prefrontal), kind (e.g., 'underactivation,' 'overactivation'), and meaning (e.g., functional deficits, compensation) of these changes. Less is known about how functional connections between specific brain regions are affected by age and how these changes are related to behavioral performance. To address these issues, we used functional magnetic resonance imaging to examine retrieval-related brain activation and functional connectivity in 18 younger individuals and 18 older individuals. We assessed working memory with a modified version of the Corsi Block-Tapping test, which requires the storage and reproduction of spatial target sequences. Analyses of group differences in brain activation and functional connectivity included comparisons between younger individuals, older individuals, older high-performers, and older low-performers. In addition, we conducted a functional connectivity analysis by using a seed region approach. In comparison to younger individuals, older individuals showed lower right-hemispheric dorsolateral prefrontal activation and lower functional connectivity between the right dorsolateral prefrontal cortex and the bilateral orbitofrontal cortex. Older high-performers showed higher right dorsolateral and anterior prefrontal cortex activation than older low-performers, as well as higher functional connectivity between these brain regions. The present results suggest age-related reductions of prefrontal activation during spatial working memory retrieval. Moreover, task-related functional connectivity appears to be lower in older adults. Performance accuracy in older adults is associated with right dorsolateral and anterior prefrontal cortex activation, and with the functional connection between these regions.
健康衰老伴随着空间工作记忆的衰退，这与空间工作记忆网络内的大脑功能变化有关。在过去十年中，出现了关于这些变化的位置（如前额叶）、类型（如“激活不足”“激活过度”）和意义（如功能缺陷、代偿）的重要研究结果。关于特定脑区之间的功能连接如何受年龄影响以及这些变化如何与行为表现相关，人们了解得较少。为了解决这些问题，我们使用功能磁共振成像来检查18名年轻人和18名年老人在检索相关的大脑激活和功能连接情况。我们用改良版的科西块点击测试评估工作记忆，该测试要求存储和再现空间目标序列。对大脑激活和功能连接的组间差异分析包括年轻人、年老人、老年高表现者和老年低表现者之间的比较。此外，我们采用种子区域方法进行了功能连接分析。与年轻人相比，年老人右侧半球背外侧前额叶激活较低，右侧背外侧前额叶皮质与双侧眶额皮质之间的功能连接也较低。老年高表现者比老年低表现者表现出更高的右侧背外侧和前额叶前部皮质激活，以及这些脑区之间更高的功能连接。目前的结果表明，在空间工作记忆检索过程中，前额叶激活存在与年龄相关的减少。此外，老年人与任务相关的功能连接似乎较低。老年人的表现准确性与右侧背外侧和前额叶前部皮质激活以及这些区域之间的功能连接有关。
