Objectives Age-related differences in cognition are typically assessed by comparing groups of older to younger participants, but little is known about the continuous trajectory of cognitive changes across age, or when a shift to older adulthood occurs. We examined the pattern of mean age differences and variability on episodic memory and executive function measures over the adult life span, in a more fine-grained way than past group or life-span comparisons. Method We used a sample of over 40,000 people aged 18–90 who completed psychometrically validated online tests measuring episodic memory and executive functions (the Cogniciti Brain Health Assessment). Results Cognitive performance declined gradually over adulthood, and rapidly later in life on spatial working memory, processing speed, facilitation (but not interference), associative recognition, and set shifting. Both polynomial and segmented regression fit the data well, indicating a nonlinear pattern. Segmented regression revealed a shift from gradual to rapid decline that occurred in the early 60s. Variability between people (interindividual variability or diversity) and variability within a person across tasks (intraindividual variability or dispersion) also increased gradually until the 60s, and rapidly after. Confirmatory factor analysis revealed a single general factor (of variance shared between tasks) offered a good fit for performance across tasks. Discussion Life-span cognitive performance shows a nonlinear pattern, with gradual decline over early and mid-adulthood, followed by a transition in the 60s to notably accelerated, but more variable, decline. Some people show less decline than others, and some cognitive abilities show less within-person decline than others.

中文翻译：

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当我 64 岁时：超过 40,000 名在线认知测试者的年龄相关变异性

目标 与年龄相关的认知差异通常通过比较老年和年轻参与者的群体来评估，但对于跨年龄的认知变化的连续轨迹，或者何时发生转变为成年期，我们知之甚少。我们以比过去的组或寿命比较更细粒度的方式检查了成人寿命期间情景记忆和执行功能测量的平均年龄差异和变异性模式。方法 我们使用了超过 40,000 名 18-90 岁的人的样本，他们完成了经心理测量学验证的在线测试，测量情景记忆和执行功能（认知大脑健康评估）。结果认知能力在成年后逐渐下降，在以后的生活中空间工作记忆、处理速度、促进（但不是干扰）、联想识别和集合转移。多项式和分段回归都很好地拟合了数据，表明了非线性模式。分段回归揭示了 60 年代初发生的从逐渐下降到快速下降的转变。人与人之间的变异性（个体间变异性或多样性）和一个人内跨任务的变异性（个体内变异性或分散性）也逐渐增加，直到 60 年代，之后迅速增加。验证性因素分析揭示了一个单一的一般因素（任务之间共享的方差）非常适合跨任务的性能。讨论 终身认知表现呈非线性模式，在成年早期和中期逐渐下降，随后在 60 年代过渡到明显加速但变化更大的下降。有些人的衰退比其他人少，