Ferrer Emilio, Salthouse Timothy A, McArdle John J, Stewart Walter F, Schwartz Brian S
Department of Psychology, University of California, Davis, CA 95616-8686, USA.
Psychol Aging. 2005 Sep;20(3):412-22. doi: 10.1037/0882-7974.20.3.412.
Longitudinal multivariate mixed models were used to examine the correlates of change between memory and processing speed and the contribution of age and retest to such change correlates. Various age- and occasion-mixed models were fitted to 2 longitudinal data sets of adult individuals (N>1,200). For both data sets, the results indicated that the correlation between the age slopes of memory and processing speed decreased when retest effects were included in the model. If retest effects existed in the data but were not modeled, the correlation between the age slopes was positively biased. The authors suggest that although the changes in memory and processing speed may be correlated over time, age alone does not capture such a covariation.
采用纵向多变量混合模型来检验记忆与处理速度之间变化的相关因素，以及年龄和重测对此类变化相关因素的贡献。将各种年龄和时间点混合模型应用于两个成年个体的纵向数据集（N>1200）。对于这两个数据集，结果表明，当模型中纳入重测效应时，记忆和处理速度的年龄斜率之间的相关性降低。如果数据中存在重测效应但未进行建模，年龄斜率之间的相关性会产生正偏差。作者认为，尽管记忆和处理速度的变化可能随时间相关，但仅年龄并不能反映这种协变关系。
