Department of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden.
Arch Gerontol Geriatr. 2013 Jul-Aug;57(1):100-9. doi: 10.1016/j.archger.2013.02.010. Epub 2013 Mar 27.
The present study investigated the extent to which the effect of age on cognitive ability is predicted by individual differences in physical health. The sample consisted of 118 volunteer subjects who were healthy and ranging in age from 26 to 91. The examinations included a clinical investigation, magnetic resonance imaging (MRI) brain neuroimaging, and a comprehensive neuropsychological assessment. The effect of age on fluid IQ with and without visual spatial praxis and on crystallized IQ was tested whether being fully-, partially- or non-mediated by physical health. Structural equation analyses showed that the best and most parsimonious fit to the data was provided by models that were fully mediated for fluid IQ without praxis, non-mediated for crystallized IQ and partially mediated for fluid IQ with praxis. The diseases of the circulatory and nervous systems were the major mediators. It was concluded from the pattern of findings that the effect of age on fluid intelligence is fully mediated by physical health, while crystallized intelligence is non-mediated and visual spatial praxis is partially mediated, influenced mainly by direct effects of age. Our findings imply that improving health by acting against the common age-related circulatory- and nervous system diseases and risk factors will oppose the decline in fluid intelligence with age.
本研究旨在探讨个体身体健康差异对认知能力随年龄变化的影响程度。样本由 118 名志愿者组成，他们身体健康，年龄在 26 岁至 91 岁之间。检查包括临床调查、磁共振成像 (MRI) 脑神经影像学和全面的神经心理学评估。研究测试了身体健康是否完全、部分或非中介影响流体智商（包括和不包括视觉空间实践）和晶体智商。结构方程分析表明，最适合和最简约的数据模型是流体智商无实践的完全中介模型，晶体智商无中介模型，流体智商有实践的部分中介模型。循环系统和神经系统疾病是主要的中介因素。研究结果表明，年龄对流体智力的影响完全由身体健康中介，而晶体智力不受中介，视觉空间实践部分受中介，主要受年龄的直接影响。我们的研究结果表明，通过对抗常见的与年龄相关的循环系统和神经系统疾病及风险因素来改善健康状况，可以减缓流体智力随年龄下降的速度。
