Cognitive and social functioning across adulthood: Age or student status differences?

Spatial abilities and aging: a meta-analysis

BACKGROUND/STUDY CONTEXT: Age-related effects in performance on spatial tasks have been well documented, with results suggesting a negative effect on performance in older samples. Although meta-analyses have been conducted examining performance on specific spatial tasks, it appears that data incorporating a variety of tasks have not yet been integrated into a single meta-analyses.

METHODS

The present study examined age-related effects on spatial abilities in a multilevel meta-analysis of 137 effect sizes, drawn from 80 samples dated between 1958 and 2011. In addition to sample characteristics (education, year of publication, and age range), procedural factors (spatial ability category, spatial task, dependent variable, task setting, and medium of administration) were also considered. The standardized mean difference (Cohen's d) was used as the effect size measure in meta-analytic calculations.

RESULTS

RESULTS revealed a large (mean d = 1.01) age-related decrease in spatial performance on psychometric tests. Specifically, older adults (mean age range = 63-79.5 years) performed worse on psychometric tests than younger adults (mean age range = 17-28.6 years). Interestingly, this age effect was unaffected by factors such as specific test, test category (mental rotation, spatial perception, or spatial visualization), timing conditions, and group or individual administration. However, measures of response time produced significantly larger effects of age than measures of accuracy on spatial performance.

CONCLUSION

The present analysis demonstrates a clear pattern of negative age effects in spatial ability across the literature. Although these effects are unaffected by the specific spatial component under investigation or testing conditions, speed of processing was shown to be an important factor in spatial performance. The need to report more thoroughly on characteristics of young and old participants in future studies is also emphasized.

Age differences in the nature and origin of individual differences in memory: a behavior genetic analysis

Measures of memory performance and cognitive and lifestyle variables were obtained from 147 younger twin pairs (27 to 60 years) and 194 older twin pairs (60 to 94 years) as part of the Minnesota Twin Study of Adult Development and Aging. Correlational and behavior genetic analyses were combined to investigate age differences in 1) the relationship between memory performance and cognitive and lifestyle variables, 2) genetic and environmental influences on memory performance, and 3) genetic and environmental mediation of the relationship between memory and predictor variables. No age differences in heritability were found. Qualitative age differences in memory processes were suggested by age group differences in the correlations between memory and cognitive factors. Even though age differences in phenotypic correlations had been demonstrated, no age differences in the genetic and environmental mediation of the correlations were found. In other words, the magnitude of the correlation between memory and cognitive factors varied across age groups but the nature of the relationship did not.

Memory, language, and ageing

This overview provides both theoretical and empirical reasons for emphasizing practice and familiar skills as a practical strategy for enhancing cognitive functioning in old age. Our review of empirical research on age-related changes in memory and language reveals a consistent pattern of spared and impaired abilities in normal old age. Relatively preserved in old age is memory performance involving highly practised skills and familiar information, including factual, semantic and autobiographical information. Relatively impaired in old age is memory performance that requires the formation of new connections, for example, recall of recent autobiographical experiences, new facts or the source of newly acquired facts. This pattern of impaired new learning versus preserved old learning cuts across distinctions between semantic memory, episodic memory, explicit memory and perhaps also implicit memory. However, familiar verbal information is not completely preserved when accessed on the output side rather than the input side: aspects of language production, namely word finding and spelling, exhibit significant age-related declines. This emerging pattern of preserved and impaired abilities presents a fundamental challenge for theories of cognitive ageing, which must explain why some aspects of language and memory are more vulnerable to the effects of ageing than others. Information-universal theories, involving mechanisms such as general slowing that are independent of the type or structure of the information being processed, require additional mechanisms to account for this pattern of cognitive aging. Information-specific theories, where the type or structure of the postulated memory units can influence the effects of cognitive ageing, are able to account for this emerging pattern, but in some cases require further development to account for comprehensive cognitive changes such as general slowing.

Memory performance in relation to age, verbal ability, and activity

Young and old adults completed a vocabulary test, the Activities Frequency Inventory (AFI), the Activity Preference Scale (APS), and memory tests that sampled six domains of everyday memory. The young adults' memory performance was significantly higher than the old adults'. Memory was better for the high-APS young than for the low-APS young and for the high-AFI old than for the low-AFI old. However, the age gap in memory performance was not closed when a subsample of active elderly was compared with a subsample of inactive young. Also, in regression analyses, neither activity measure added significantly to the vocabulary measure in predicting memory performance for either age group.