Department of Psychiatry, Center for Behavior Genetics of Aging, University of California, San Diego.
Department of Psychology, University of California, Riverside.
Psychol Aging. 2018 Mar;33(2):219-231. doi: 10.1037/pag0000230.
Research on executive functions (EFs) has revealed that individual differences in general EF abilities are highly correlated across the first few decades of life, especially at the level of genetic influences. Our work has also provided evidence for substantial heritability of this Common EF factor in midlife, but it remains unclear whether individual differences in Common EFs continue to show strong stability in middle age. We examined data from 1,464 middle-aged twins from the Vietnam Era Twin Study of Aging, most of whom completed 7 neuropsychological measures of EFs at 2 points in middle age (M = 56 and 62). Confirmatory factor analysis indicated that individual differences in Common EF, a latent factor explaining variation in seven neuropsychological EF tasks, were highly correlated across this 6-year period (r = .97), and that the same genetic and environmental influences were operating across this interval (genetic and shared environmental correlations = 1.0, nonshared environment correlation = .95). Similar phenotypic and genetic stability was observed for a Working Memory (WM)-Specific latent factor, which explained additional variance in working memory span tasks not captured by Common EF (r = .98, genetic correlation = 1.0, nonshared environmental correlation = .88). There was a large mean-level performance decline in Common EF (d = -.60) but not WM-Specific (d = -.03). These results suggest that there is substantial decline in Common EF abilities across middle age but that individual differences are almost perfectly stable. (PsycINFO Database Record
执行功能（EFs）的研究表明，个体在 EF 能力方面的差异在生命的头几十年中高度相关，尤其是在遗传影响方面。我们的工作还为中年时期这种共同 EF 因素的大量遗传提供了证据，但尚不清楚共同 EF 个体差异在中年是否仍具有很强的稳定性。我们研究了来自越南时代老化双胞胎研究的 1464 对中年双胞胎的数据，其中大多数人在中年的两个时间点（M = 56 和 62）完成了 7 项神经心理学 EF 测量。验证性因素分析表明，解释七种神经心理学 EF 任务变化的共同 EF 潜在因素的个体差异在这 6 年期间高度相关（r =.97），并且相同的遗传和环境影响在这一期间起作用（遗传和共享环境相关性= 1.0，非共享环境相关性=.95）。工作记忆（WM）特定的潜在因素也观察到了类似的表型和遗传稳定性，该因素解释了共同 EF 无法捕捉到的工作记忆广度任务的额外方差（r =.98，遗传相关性= 1.0，非共享环境相关性=.88）。共同 EF 存在较大的平均水平表现下降（d = -.60），但 WM 特定的没有（d = -.03）。这些结果表明，在中年时期，共同 EF 能力有很大的下降，但个体差异几乎是完全稳定的。
