Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
Department of Psychology, University of Victoria, Victoria, BC, Canada.
PLoS One. 2024 Jun 24;19(6):e0305818. doi: 10.1371/journal.pone.0305818. eCollection 2024.
With a globally aging population, there is a need to better understand how brain structure relates to function in healthy older and younger adults.
34 healthy participants divided into older (17; Mean = 70.9, SD = 5.4) and younger adults (17; Mean = 28.1, SD = 2.8) underwent diffusion-weighted imaging and neuropsychological assessment, including the California Verbal Learning Test 2nd Edition and the Trail Making Test (TMT-A and TMT-B). Differences in white matter microstructure for older and younger adults and the association between DTI metrics (fractional anisotropy, FA; mean diffusivity, MD) and cognitive performance were analyzed using tract-based spatial statistics (p < 0.05, corrected).
Older adults had significantly lower FA and higher MD than younger adults in widespread brain regions. There was a significant negative correlation between executive function (TMT-B) and MD for older adults in the right superior/anterior corona radiata and the corpus callosum. No significant relationship was detected between DTI metrics and executive function in younger adults or with memory performance in either group.
The findings underscore the need to examine brain-behaviour relationships as a function of age. Future studies should include comprehensive assessments in larger lifespan samples to better understand the aging brain.
随着全球人口老龄化，我们需要更好地了解健康的老年人和年轻人的大脑结构与功能之间的关系。
34 名健康参与者分为老年人组（17 人；平均年龄=70.9，标准差=5.4）和年轻人组（17 人；平均年龄=28.1，标准差=2.8），他们接受了弥散张量成像和神经心理学评估，包括加州语言学习测试第二版和连线测试（TMT-A 和 TMT-B）。使用基于束的空间统计学（p<0.05，校正）分析了老年人和年轻人之间的白质微观结构差异以及 DTI 指标（各向异性分数，FA；平均弥散度，MD）与认知表现之间的关联。
老年人在广泛的大脑区域的 FA 明显低于年轻人，MD 明显高于年轻人。在右侧上/前辐射冠和胼胝体中，执行功能（TMT-B）与 MD 之间存在显著的负相关关系。在年轻人中，DTI 指标与执行功能之间或在两组中与记忆表现之间均未检测到显著关系。
这些发现强调了需要根据年龄来检查大脑-行为关系。未来的研究应包括在更大的生命周期样本中进行全面评估，以更好地了解衰老的大脑。
