Department of Psychology, University of Victoria, Victoria, British Columbia, Canada.
Psychol Aging. 2010 Sep;25(3):575-86. doi: 10.1037/a0019503.
In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability.
在这项研究中，作者探讨了个体内变异性的纵向性质，历时 3 年。研究样本为 304 名居住在社区的老年人，最初年龄在 64 至 92 岁之间，他们在 4 年内完成了一系列基于准确性和潜伏期的测试，涵盖了广泛的认知复杂性。在中度和高度复杂任务中反应时不一致性的增加与年龄的增加有关，但整个样本中变化的个体差异显著。认知与不一致性之间的时变协方差在 1 年间隔内是显著的，并且在时间和年龄上都是稳定的。当个体内变异性较高时，参与者的认知表现相应较低。在更流畅的认知领域（如记忆、推理和处理速度），耦合关系的强度大于更结晶化的领域（如言语能力）。基于中度和高度复杂任务的变异性提供了最强的预测。这些结果表明，个体内变异性对认知能力的甚至细微变化非常敏感。
