Meta-analyses of age–cognition relations in adulthood: Estimates of linear and nonlinear age effects and structural models.

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Working Memory Workout: How to Expand the Focus of Serial Attention From One to Four Items in 10 Hours or Less.

Five individuals participated in an extensive practice study (10 1-hr sessions, 11,000 trials total) on a self-paced identity-judgment n-back task (n ranging from 1 to 5). Within Session 1, response time increased abruptly by about 300 ms in passing from n = 1 to n > 1, suggesting that the focus of attention can accommodate only a single item (H. Caravan, 1998; B. McElree, 2001). Within Session 10, response time was dramatically reduced and increased linearly with n for n ≤ 4, with a slope of about 30 ms. The data suggest that working memory consists of a focus of attention governed by a limited-capacity search, expandable through practice, and a content-addressable region outside the focus of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and task switching: A meta-analysis.

A meta-analysis of 26 published articles (with 36 independent participant groups) was conducted to analyze the relationship between task-switching effects and aging. Latency served as the dependent measure. Multilevel modeling was used to test for additive and multiplicative complexity effects in local and global switch costs. Global task switching was found to add 1 or more stages to processing and resulted in a marked age deficit. Local task-switching costs, on the other hand, showed a multiplicative complexity effect but no specific attention-related age deficits. Cueing or switch predictability did not affect age differences. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The effects of learning a new algorithm on asymptotic accuracy and execution speed in old age: A reanalysis.

Time-accuracy curves were derived for 16 younger and 19 older persons who participated in a study on training in the method of loci (Baltes & Kliegl, 1992). The effects of instruction were to immediately and permanently boost asymptotic performance and initially slow down the rate of approach to the asymptote. After extensive practice, rate of approach returned to the initial fast level. Age differences were found in both asymptotic performance and rate of approach. The effects of instruction and practice, however, were similar in younger and older adults, but older adults needed 1 session of instruction more than younger adults did before the intervention showed its full effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why We Sing the Blues: The Relation Between Self-Reflective Rumination, Mood, and Creativity.

Past research has shown that creative behavior is associated with a higher risk for depression. The authors hypothesized that a 3rd underlying factor, namely, self-reflective rumination, may explain the connection. This hypothesis was examined in a sample of 99 undergraduate college students, using path analysis. The authors found that self-reported past depressive symptomatology was linked to increased self-reflective rumination. Rumination, in turn, was related to current symptomatology and to self-rated creative interests and objectively measured creative fluency, originality, and elaboration. No direct link existed between currently depressed mood and either creative interest or creative behavior. These results suggest that the association between depression and creativity is solely the result of rumination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and the negative priming effect: A meta-analysis.

This article reports results from a meta-analysis on adult age differences in the negative priming effect (21 studies on identity negative priming and 8 on location negative priming). Both younger and older adults were found to be susceptible to the negative priming effect in identity and location tasks. Effect sizes were homogeneous for both tasks, indicating that the data are adequately described without reference to moderator variables. State trace analysis on identity tasks, in which mean latencies in negative priming conditions were regressed onto mean latencies in baseline conditions, showed (a) that in both age groups the negative priming effect is proportional rather than additive and (b) that the negative priming effect is smaller in older adults as compared with younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and the Stroop effect: A meta-analysis.

In this meta-analysis, data from 20 studies comparing younger and older adults on the Stroop interference effect, contained in 15 articles, were analyzed. No significant difference was found in the Stroop interference effect, expressed as mean standardized difference, between the 2 age groups (for younger adults: d?=?2.04; for older adults: d?=?2.17). Moderator variables were present, but these did not produce age differences. Brinley analysis showed that a single regression line with a slowing factor of 1.9 described the data well (R2?=?.83) and confirmed that no Age?×?Condition interaction was present in the data. Likewise, no Age?×?Condition interaction was found when the data were fitted to the information loss model; the age ratio of decay rates was estimated to be 1.4. Consequently, the apparent age-sensitivity of the Stroop interference effect appears to be merely an artifact of general slowing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequential and coordinative complexity in time–accuracy functions for mental arithmetic.

Time–accuracy functions for tasks involving single-digit mental addition and subtraction were derived in a sample of 18 younger (mean age?=?21.7 years) and 16 older adults (mean age?=?68.8 years). Sequential complexity was manipulated by varying the number of operations (5 vs. 10); coordinative complexity was induced by bracketing. Age differences were apparent in the coordinative conditions, even though no age difference was present in the sequential conditions. This indicates that the age difference under conditions of high coordinative demands could not be attributed solely to a decline in basic speed of processing. The Age?×?Complexity interaction was due to larger onset times and lower asymptotic performance by the older adults in the coordinative conditions but not due to to rate of approach to the asymptote. This implies that coordinative demands do not differentially hurt access from semantic memory in older adults; however, coordinative demands do have disproportionately negative consequences for computation speed and self-monitoring in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory and aging: Separating the effects of content and context.

In 3 experiments, we investigated the hypothesis that age-related differences in working memory might be due to the inability to bind content with context. Participants were required to find a repeating stimulus within a single series (no context memory required) or within multiple series (necessitating memory for context). Response time and accuracy were examined in 2 task domains: verbal and visuospatial. Binding content with context led to longer processing time and poorer accuracy in both age groups, even when working memory load was held constant. Although older adults were overall slower and less accurate than young adults, the need for context memory did not differentially affect their performance. It is therefore unlikely that age differences in working memory are due to specific age-related problems with content-with-context binding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The fate of cognition in very old age: Six-year longitudinal findings in the Berlin Aging Study (BASE).

The authors report full-information longitudinal age gradients in 4 intellectual abilities on the basis of 6-year longitudinal changes in 132 individuals (mean age at T? = 79.27, age range = 70-100) from the Berlin Aging Study. Relative to the cross-sectional parent sample (N = 516, mean age at T? = 84.92 years), this sample was positively selected because of differential mortality and experimental attrition. Perceptual speed, memory, and fluency declined with age. In contrast, knowledge remained stable up to age 90, with evidence for decline thereafter. Age gradients were more negative in old old (n = 66, mean age at T? = 83.04) than in old (n = 66, mean age at T? = 73.77) participants. Rates of decline did not differ reliably between men and women or between participants with high versus low life-history status. They conclude that intellectual development after age 70 varies by distance to death, age, and intellectual ability domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)