Evaluating the relationship between change in performance on training tasks and on untrained outcomes.

Training interventions for older adults are designed to remediate performance on trained tasks and to generalize, or transfer, to untrained tasks. Evidence for transfer is typically based on the trained group showing greater improvement than controls on untrained tasks, or on a correlation between gains in training and in transfer tasks. However, this ignores potential correlational relationships between trained and untrained tasks that exist before training. By accounting for crossed (trained and untrained) and lagged (pre-training and post-training) and cross-lagged relationships between trained and untrained scores in structural equation models, the training-transfer gain relationship can be independently estimated. Transfer is confirmed if only the trained but not control participants' gain correlation is significant. Modeling data from the Improvement in Memory with Plasticity-based Adaptive Cognitive Training (IMPACT) study (Smith et al., 2009), transfer from speeded auditory discrimination and syllable span to list and text memory and to working memory was demonstrated in 487 adults aged 65-93. Evaluation of age, sex, and education on pretest scores and on change did not alter this. The overlap of the training with transfer measures was also investigated to evaluate the hypothesis that performance gains in a non-verbal speeded auditory discrimination task may be associated with gains on fewer tasks than gains in a verbal working memory task. Gains in speeded processing were associated with gains on one list memory measure. Syllable span gains were associated with improvement in difficult list recall, story recall, and working memory factor scores. Findings confirmed that more overlap with task demands was associated with gains to more of the tasks assessed, suggesting that transfer effects are related to task overlap in multimodal training.

Alcohol abstinence, non-hazardous use and hazardous use a decade after alcohol-related hospitalization: registry data linked to population-based representative postal surveys.

BACKGROUND: Although there is evident association between alcohol-related hospitalization and alcohol use, the relationship has not been well examined. This study analyzed the extent of alcohol abstinence, non-hazardous use and hazardous use among people who had experienced alcohol-related hospitalization during the preceding decade. METHOD: Registry data concerning alcohol-related hospitalizations between 1996 and 2007 were linked to two representative surveys, in 2006 and 2007, of residents of Stockholm County. Relevant contrasts were modeled, using logistic regression, in the pooled sample (n = 54 955). Ages were 23-84 years at follow-up. RESULTS: Among persons previously hospitalized (n = 576), half reported non-hazardous use. Non-hazardous use was less prevalent than in the general population--and the extent of non-hazardous use did not change over time following hospitalization. There were no significant age differences, but non-hazardous use was less frequent among people with repeated episodes of care. One in six was abstinent. Abstinence was more common among the old, while hazardous use (exceeding 14 drinks per week for men, and 9 drinks per week for women) decreased with age. Abstinence also increased over time; among persons hospitalized ten years ago, the abstinence rate was twice that of the general population. Associations with hazardous use over time were less conclusive. Hazardous use among those previously hospitalized decreased over time in one sample but not in the other. After pooling the data, there were indications of a decrease over time following hospitalization, but more prevalent hazardous use than in the general population. CONCLUSIONS: Following alcohol-related hospitalization, abstinence increased, and there was no evidence of regression towards the mean, i.e., towards non-hazardous use. Abstinence was also more widespread among previously hospitalized persons of older ages. With advancing age, changing hazardous alcohol habits among previously hospitalized appears to yield a trend towards promotion of abstinence.

Cognitively Stimulating Activities: Effects on Cognition across Four Studies with up to 21 Years of Longitudinal Data.

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.

Dynamic associations of change in physical activity and change in cognitive function: coordinated analyses of four longitudinal studies.

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.

Social activity and cognitive functioning over time: a coordinated analysis of four longitudinal studies.

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.

Changes in sobriety in the Swedish population over three decades: age, period or cohort effects?

AIMS: This study aimed to examine age, cohort and period trends in alcohol abstinence. DESIGN: Two surveys, the Level of Living Survey collected in 1968, 1974, 1981, 1990 and 2000, and the Swedish Panel Study of the Oldest Old (SWEOLD) collected in 1992 and 2002, were studied with graphical depictions of cross-sectional and longitudinal data presented over time and over age. Cross-sectional 10-year age group differences, time-lag differences between waves and within-cohort differences between waves for 10-year birth cohorts were examined. Logistic regression models were applied to confirm the observed patterns. SETTING: The samples were representative of the Swedish population. PARTICIPANTS: Participants ranged in age from 18 to 75 (n = 5000 per wave), and 77+ at later waves (n = 500). MEASUREMENTS: Alcohol abstinence was determined by asking 'Do you ever drink wine, beer, or spirits?', where a 'no' response indicated abstinence. FINDINGS: Decreases in abstinence rates were observed from 1968 to 2000/02. While cross-sectional analysis indicated increased abstinence with advancing age, the longitudinal analysis suggested otherwise. Inspection of cohort differences revealed little change within cohorts and large differences between cohorts; abstinence rates declined in later-born cohorts up to the 1940s birth cohorts; stability was observed in cohorts born since the 1940s. Logistic regression models indicated that neither age nor period were significant (P > 0.05) predictors of abstinence when cohort (P < 0.001) was included. CONCLUSION: Decreasing proportions of total alcohol abstainers in Sweden from 1968 to 2000 appear to be attributable primarily to decreases in successive cohorts rather than drinkers becoming abstainers.

Improvement in memory with plasticity-based adaptive cognitive training: results of the 3-month follow-up.

OBJECTIVES: To investigate maintenance of training effects of a novel brain plasticity-based computerized cognitive training program in older adults after a 3-month no-contact period. DESIGN: Multisite, randomized, controlled, double-blind trial with two treatment groups. SETTING: Communities in northern and southern California and Minnesota. PARTICIPANTS: Four hundred eighty-seven community-dwelling adults aged 65 and older without diagnosis of clinically significant cognitive impairment. INTERVENTION: Random assignment into a broadly available brain plasticity-based computerized cognitive training program experimental group or a novelty- and intensity-matched cognitive stimulation active control. Assessments at baseline, after training, and at 3 months. MEASUREMENTS: The primary outcome was a composite of auditory subtests of the Repeatable Battery for the Assessment of Neuropsychological Status. Secondary measures included trained task performance, standardized neuropsychological assessments of overall memory and attention, and participant-reported outcomes (PROs). RESULTS: A significant difference in improvement from baseline to 3-month follow-up was seen between the experimental training and control groups on the secondary composite of overall memory and attention, (P=.01, d=0.25), the trained processing-speed measure (P<.001, d=0.80), word list total recall (P=.004, d=0.28), letter-number sequencing (P=.003, d=0.29), and the cognitive subscale of PRO (P=.006, d=0.27). Previously significant improvements became nonsignificant at the 3-month follow-up for the primary outcome, two secondary measures of attention and memory, and several PROs. Narrative memory continued to show no advantage for the experimental group. Effect sizes from baseline to follow-up were generally smaller than effect sizes from baseline to posttraining. CONCLUSION: Training effects were maintained but waned over the 3-month no-contact period.

A cognitive training program based on principles of brain plasticity: results from the Improvement in Memory with Plasticity-based Adaptive Cognitive Training (IMPACT) study.

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.

Not your parents' test scores: cohort reduces psychometric aging effects.

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.

Estimating age change in list recall in asset and health dynamics of the oldest-old: the effects of attrition bias and missing data treatment.

Average change in list recall was evaluated as a function of missing data treatment (Study 1) and dropout status (Study 2) over ages 70 to 105 in Asset and Health Dynamics of the Oldest-Old data. In Study 1 the authors compared results of full-information maximum likelihood (FIML) and the multiple imputation (MI) missing-data treatments with and without independent predictors of missingness. Results showed declines in all treatments, but declines were larger for FIML and MI treatments when predictors were included in the treatment of missing data, indicating that attrition bias was reduced. In Study 2, models that included dropout status had better fits and reduced random variance compared with models without dropout status. The authors conclude that change estimates are most accurate when independent predictors of missingness are included in the treatment of missing data with either MI or FIML and when dropout effects are modeled.

Bias effects in word fragment completion in young and older adults.

Young and older adults were tested on a word fragment completion task in which correct solutions were studied words, words orthographically similar to studied words, or new words. In Experiments 1 and 2, the standard production version of the word fragment completion task was used; older adults had reduced benefits of prior exposure to target words and slightly decreased costs. However, costs and benefits did not differ across age in a forced-choice version of the task (Experiment 3). At a behavioral level, the results are contrary to predictions that age differences in word fragment completion priming effects will be greater when there is a strong competitor for the correct solution and that age differences in both costs and benefits will be smaller for identification than for production tasks. Theoretical implications of these findings are considered.