A meta-analysis was conducted on 91 studies to derive a correlation matrix for adult age, speed of processing, primary-working memory, episodic memory, reasoning, and spatial ability. Structural equation modeling with a single latent common cognitive factor showed that all cognitive measures shared substantial portions of age-related variance. A mediational model revealed that speed of processing and primary-working memory appear to be important mediators of age-related differences in the other measures. However, not all of the age-related influences were mediated. An examination of quadratic age effects and correlational patterns for subsamples under and over 50 years of age revealed that (a) negative age-cognition relations were significant for the 18- to 50-year-old sample and (b) the age-related decline accelerated significantly over the adult life span for variables assessing speed, reasoning, and episodic memory.

No abstract

The effectiveness of memory training for the elderly was examined through a meta-analysis of pre-to-posttest gains on episodic memory tasks in healthy subjects aged 60 or above. Pre-to-posttest gains were found to be significantly larger in training groups (0.73 SD, k = 49) than in both control (0.38 SD, k = 10) and placebo (0.37 SD, k = 8) groups. Treatment gains in training groups were negatively affected by age of participants and duration of training sessions and positively affected by group treatment, pretraining, and memory-related interventions. No differences in treatment gain were obtained as a function of type of mnemonic taught nor the kind of pretraining used.

Vocabulary scores were examined in a total of 210 articles, containing 324 independent pairings of younger and older adults, from the 1986-2001 issues of Psychology and Aging. The average effect size, favoring the old, was 0.80 SD. Production tests yielded smaller effects (0.68 SD) than multiple-choice tests (0.93 SD). Both age and education were found to be partially independent determinants of performance in production tests; age effects disappeared in multiple-choice tests as soon as education was taken into account. In addition, the Wechsler Adult Intelligence Scale--Revised Vocabulary subtest (D. Wechsler, 1981) was also found to be sensitive to the Flynn effect (J. R. Flynn, 1987; i.e., increasing test scores with advancing birth year). The results question the approach of using age-group equality in vocabulary scores as a check on sample equivalence.

This meta-analysis examined the effects of process-based cognitive training (49 studies) in the domains of executive function and working memory in older adults (>60 years). The interventions resulted in significant effects on the trained task (pre-to-posttest net gain: MSD = 0.5 compared to active control, MSD = 0.8 compared to passive control; net posttest effect: MSD = 1.2 compared to active control, MSD = 1.1 compared to passive control), significant near transfer (pre-post: MSD = 0.3, 0.3; posttest: MSD = 0.6, 0.4); far-transfer effects were significant in 3 out of 4 comparisons (pre-post: MSD = 0.2, 0.2; net gain at posttest: MSD = 0.3, 0.2, ns). We detected small differences in training-induced improvements between working-memory and executive-functioning training, but none between older adults and the younger-adult samples included in these studies, adaptive and non-adaptive training, or active and passive control conditions. Gains did not vary with total training time.