OBJECTIVES To investigate the efficacy of a novel brain plasticity–based computerized cognitive training program in older adults and to evaluate the effect on untrained measures of memory and attention and participant-reported outcomes. DESIGN Multisite randomized controlled double-blind trial with two treatment groups. SETTING Communities in northern and southern California and Minnesota. PARTICIPANTS Community-dwelling adults aged 65 and older (N = 487) without a diagnosis of clinically significant cognitive impairment. INTERVENTION Participants were randomized to receive a broadly-available brain plasticity–based computerized cognitive training program (intervention) or a novelty- and intensity-matched general cognitive stimulation program modeling treatment as usual (active control). Duration of training was 1 hour per day, 5 days per week, for 8 weeks, for a total of 40 hours. MEASUREMENTS The primary outcome was a composite score calculated from six subtests of the Repeatable Battery for the Assessment of Neuropsychological Status that use the auditory modality (RBANS Auditory Memory/Attention). Secondary measures were derived from performance on the experimental program, standardized neuropsychological assessments of memory and attention, and participant-reported outcomes. RESULTS RBANS Auditory Memory/Attention improvement was significantly greater (P = .02) in the experimental group (3.9 points, 95% confidence interval (CI) = 2.7–5.1) than in the control group (1.8 points, 95% CI = 0.6–3.0). Multiple secondary measures of memory and attention showed significantly greater improvements in the experimental group (word list total score, word list delayed recall, digits backwards, letter–number sequencing; P < .05), as did the participant-reported outcome measure (P = .001). No advantage for the experimental group was seen in narrative memory. CONCLUSION The experimental program improved generalized measures of memory and attention more than an active control program.

Training effects were maintained but waned over the 3-month no-contact period.

Transfer-appropriate processing theories differentiate between conceptual-and perceptual-priming tasks. The former are said to be influenced by the nature of processing engaged in at study, but not by changes in modality between study and test; the latter are sensitive to changes in format between study and test, but not to variations in the extent ofsemantic processing at study. In the present experiments, we examined the effects of divided attention and aging on priming in exemplar generation and category verification, two tasks that require access to semantic information at test. Manipulations of attention during encoding affected the extent of priming in exemplar generation, but not in category verification. Priming effects were similar in young and older adults in exemplar generation following study in both full and divided attention. Although older adults did not demonstrate priming in category verification in one experiment, no effects of age or divided attention were observed in a second experiment. In addition, priming in category verification was unaffected by varying the level of processing at encoding. However, the absence of levels-of-processing and attention effects in category verification does not signal that priming in this task has a perceptual basis; priming in category verification was insensitive to modality shifts between study and test. The implications of these fmdings for theories of priming and cognitive aging are considered.Division of attention during encoding is well known to have negative consequences for performance on direct measures of memory, such as recall and recognition, that involve deliberate recollection of prior study episodes (e.g, Craik, Govoni, Naveh-Benjamin, & Anderson, 1996;Fisk & Schneider, 1984;Kellogg, 1980;Parkin, Reid, & Russo, 1990;Weldon & Jackson-Barrett, 1993). However, the consequences of dividing attention during encoding on indirect memory tasks, in which the task instructions do not mention the relation between the task to be performed and the prior study episodes, are less well understood. It is, for instance, unclear whether we should expect the effects of dividing attention to be uniform across all classes of indirect memory tasks.Recent research on the consequences of dividing attention for indirect measures of memory has been guided largely by the transfer-appropriate processing frame-

Engagement in cognitively stimulating activities has been considered to maintain or strengthen cognitive skills, thereby minimizing age-related cognitive decline. While the idea that there may be a modifiable behavior that could lower risk for cognitive decline is appealing and potentially empowering for older adults, research findings have not consistently supported the beneficial effects of engaging in cognitively stimulating tasks. Using observational studies of naturalistic cognitive activities, we report a series of mixed effects models that include baseline and change in cognitive activity predicting cognitive outcomes over up to 21 years in four longitudinal studies of aging. Consistent evidence was found for cross-sectional relationships between level of cognitive activity and cognitive test performance. Baseline activity at an earlier age did not, however, predict rate of decline later in life, thus not supporting the concept that engaging in cognitive activity at an earlier point in time increases one's ability to mitigate future age-related cognitive decline. In contrast, change in activity was associated with relative change in cognitive performance. Results therefore suggest that change in cognitive activity from one's previous level has at least a transitory association with cognitive performance measured at the same point in time.

The present study used a coordinated analyses approach to examine the association of physical activity and cognitive change in four longitudinal studies. A series of multilevel growth models with physical activity included both as a fixed (between-person) and time-varying (within-person) predictor of four domains of cognitive function (reasoning, memory, fluency, and semantic knowledge) was used. Baseline physical activity predicted fluency, reasoning and memory in two studies. However, there was a consistent pattern of positive relationships between time-specific changes in physical activity and time-specific changes in cognition, controlling for expected linear trajectories over time, across all four studies. This pattern was most evident for the domains of reasoning and fluency.

Increases over birth cohorts in psychometric abilities may impact effects of aging. Data from 2 cohorts of the Long Beach Longitudinal Study, matched on age but tested 16 years apart, were modeled over ages 55-87 to test the hypothesis that the more fluid abilities of reasoning, list and text recall, and space would show larger cohort differences than vocabulary. This hypothesis was confirmed. At age 74, average performance estimates for people from the more recently born cohort were equivalent to those of people from the older cohort when they were up to 15 years younger. This finding suggests that older adults may perform like much younger ones from the previous generation on fluid measures, indicating higher levels of abilities than expected. This result could have major implications for the expected productivity of an aging workforce as well as for the quality of life of future generations. However, cohort improvements did not mitigate age declines.

Social activity is typically viewed as part of an engaged lifestyle that may help mitigate the deleterious effects of advanced age on cognitive function. As such, social activity has been examined in relation to cognitive abilities later in life. However, longitudinal evidence for this hypothesis thus far remains inconclusive. The current study sought to clarify the relationship between social activity and cognitive function over time using a coordinated data analysis approach across four longitudinal studies. A series of multilevel growth models with social activity included as a covariate is presented. Four domains of cognitive function were assessed: reasoning, memory, fluency, and semantic knowledge. Results suggest that baseline social activity is related to some, but not all, cognitive functions. Baseline social activity levels failed to predict rate of decline in most cognitive abilities. Changes in social activity were not consistently associated with cognitive functioning. Our findings do not provide consistent evidence that changes in social activity correspond to immediate benefits in cognitive functioning, except perhaps for verbal fluency.

In 3 experiments, a pronunciation task was used to examine repetition priming of novel nonwords in young and older adults. The contributions of item and associative priming to the total repetition priming effect were assessed. In Experiment 1, age consistency was found in both components of repetition priming after 9 repetitions of nonwords. Experiment 2 established that young and older adults were similar in item and associative priming after as few as 2 repetitions of nonwords. Finally, Experiment 3 demonstrated that associative priming persists for at least 3 min and that it is dissociable from cued recall. The overall pattern of results strongly argues that elaborative processing is not necessary to obtain associative priming in indirect memory tasks and that young and older adults show similar magnitudes of associative priming.