Ram Nilam, Rabbitt Patrick, Stollery Brian, Nesselroade John R
Department of Psychology, University of Virginia, Charlottesville, VA 22904-4400, USA.
Psychol Aging. 2005 Dec;20(4):623-33. doi: 10.1037/0882-7974.20.4.623.
Although many studies have examined inconsistency of cognitive performance, few have examined how inconsistency changes over time. 91 older adults (age 52 to 79) were tested weekly for 36 consecutive weeks on a series of multitrial memory speed (i.e., letter recognition) tasks. A number of multivariate techniques were used to examine how individuals' level of inconsistency changed across weeks and how this change was related to interindividual differences in age and intelligence. Results indicated that (a) inconsistency of performance is a construct separate from the underlying performance ability (i.e., memory speed); (b) inconsistency reduces exponentially with practice; (c) individuals with higher scores on tests of fluid general intelligence (G-sub(f)) reached lower asymptotic levels of inconsistency compared to lower scorers; and (d) after controlling for the systematic effects of practice, variability in inconsistency from week-to-week was more pronounced for individuals with lower G-sub(f) scores compared to individuals with higher scores.
尽管许多研究都考察了认知表现的不一致性，但很少有研究考察这种不一致性是如何随时间变化的。91名年龄在52岁至79岁之间的老年人连续36周每周接受一系列多试次记忆速度（即字母识别）任务的测试。使用了多种多变量技术来考察个体的不一致性水平在各周之间是如何变化的，以及这种变化与年龄和智力的个体差异有何关系。结果表明：（a）表现的不一致性是一个与潜在表现能力（即记忆速度）不同的结构；（b）不一致性会随着练习呈指数级降低；（c）在流体一般智力（G-sub(f)）测试中得分较高的个体与得分较低的个体相比，达到的不一致性渐近水平更低；（d）在控制了练习的系统效应后，与得分较高的个体相比，G-sub(f)得分较低的个体在各周之间不一致性的变异性更为明显。
