Zhu Zude, Johnson Nathan F, Kim Chobok, Gold Brian T
Department of Anatomy and Neurobiology.
Department of Anatomy and Neurobiology Department of Psychology, Kyungpook National University, Daegu 702-701, South Korea.
Cereb Cortex. 2015 Jan;25(1):138-46. doi: 10.1093/cercor/bht212. Epub 2013 Aug 19.
Increased frontal cortex activation during cognitive task performance is common in aging but remains poorly understood. Here we explored patterns of age-related frontal brain activations under multiple task performance conditions and their relationship to white matter (WM) microstructure. Groups of younger (N = 28) and older (N = 33) participants completed a task-switching paradigm while functional magnetic resonance imaging (fMRI) was performed, and rested while diffusion tensor imaging was performed. Results from fMRI analyses indicated age-related increases in frontal brain activations under conditions of poorer performance in the older group (the nonswitch and switch conditions) and for a contrast in which behavioral performance was equated (older group nonswitch condition vs. younger group switch condition). Within the older adult group, higher frontal activation was associated with poorer behavioral performance under all task conditions. In 2 regions in right frontal cortex, blood oxygen level-dependent (BOLD) magnitudes were negatively correlated with WM integrity in tracts connecting these structures with other task-relevant frontoparietal and striatal regions. Our results link age-related declines in the efficiency of frontal cortex functioning with lower WM integrity in aging.
在认知任务执行过程中额叶皮质激活增加在衰老过程中很常见，但仍未得到充分理解。在这里，我们探讨了在多种任务执行条件下与年龄相关的额叶脑激活模式及其与白质（WM）微观结构的关系。年轻组（N = 28）和老年组（N = 33）参与者在进行功能磁共振成像（fMRI）时完成任务切换范式，并在进行扩散张量成像时休息。fMRI分析结果表明，在老年组表现较差的条件下（非切换和切换条件）以及行为表现相等的对比中（老年组非切换条件与年轻组切换条件），额叶脑激活与年龄相关增加。在老年成人组中，在所有任务条件下，较高的额叶激活与较差的行为表现相关。在右侧额叶皮质的2个区域，血氧水平依赖（BOLD）幅度与将这些结构与其他与任务相关的额顶叶和纹状体区域连接的束中的WM完整性呈负相关。我们的结果将衰老过程中额叶皮质功能效率与较低的WM完整性的年龄相关下降联系起来。
