Christopher Hertzog

Use It or Lose It: Engaged Lifestyle as a Buffer of Cognitive Decline in Aging?

Data from the Victoria Longitudinal Study were used to examine the hypothesis that maintaining intellectual engagement through participation in everyday activities buffers individuals against cognitive decline in later life. The sample consisted of 250 middle-aged and older adults tested 3 times over 6 years. Structural equation modeling techniques were used to examine the relationships among changes in lifestyle variables and an array of cognitive variables. There was a relationship between changes in intellectually related activities and changes in cognitive functioning. These results are consistent with the hypothesis that intellectually engaging activities serve to buffer individuals against decline. However, an alternative model suggested the findings were also consistent with the hypothesis that high-ability individuals lead intellectually active lives until cognitive decline in old age limits their activities.

Measurement properties of the center for epidemiological studies depression scale (CES−D) in older populations

Two cross-sectional samples of adults were administered the 20-item Center for Epidemiological Studies-Depression Scale (CES-D). The results support the measurement validity of the CES-D for depression screening in older adult populations

Effect of Age on Event-Based and Time-Based Prospective Memory

The magnitude of age differences on event- and time-based prospective memory tasks was investigated in 2 experiments. Participants performed a working memory task and were also required to perform either an event- or time-based prospective action. Control participants performed either the working memory task only or the prospective memory task only. Results yielded age differences on both prospective tasks. The age effect was particularly marked on the time-based task. Performance of the event-based prospective task, however, had a higher cost to performance on the concurrent working memory task than the time-based task did, suggesting that event-based responding has a substantial attentional requirement. The older adults also made a significant number of time-monitoring errors when time monitoring was their sole task. This suggests that some time-based prospective memory deficits in older adults are due to a fundamental deficit in time monitoring rather than to prospective memory.

Assessing psychological change in adulthood: an overview of methodological issues.

This article reviews the current status of methods available for the analysis of psychological change in adulthood and aging. Enormous progress has been made in designing statistical models that can capture key aspects of intraindividual change, as reflected in techniques such as latent growth curve models and multilevel (random-effects) models. However, the rapid evolution of statistical innovations may have obscured the critical importance of addressing rival explanations for statistical outcomes, such as cohort differences or practice effects that could influence estimates of age-related change. Choice of modeling technique and implementation of a specific modeling approach should be grounded in and reflect both the theoretical nature of the developmental phenomenon and the features of the sampling design that selected persons, variables, and contexts for empirical observation.

Relationships between metamemory, memory predictions, and memory task performance in adults.

A cross-sectional sample of adults recalled categorized word lists and narrative texts. Subjects gave performance predictions before each of 3 recall trials for each task. Older subjects had poorer memory performance and also predicted lower performance levels than did younger subjects. The LISREL models suggested (a) direct effects of memory self-efficacy (MSE) on initial predictions; (b) upgrading of prediction-performance correlations across trials, determined by direct effects of performance on subsequent predictions; (c) significant effects of a higher order verbal memory factor on MSE; and (d) an independent relationship of text recall ability to initial text recall performance predictions. These results lend support to the theoretical treatment of predictions as task-specific MSE judgments.

Medication Adherence in Rheumatoid Arthritis Patients: Older Is Wiser

OBJECTIVES: To create a profile of individuals nonadherent to their medications in an age‐stratified sample (ages 34–84) of community‐dwelling rheumatoid arthritis patients. The relative contributions of age, cognitive function, disability, emotional state, lifestyle, and beliefs about illness to nonadherence were assessed.

Age-Related Differences in Absolute but Not Relative Metamemory Accuracy

In 3 experiments, the effects of age on different kinds of metacognitive prediction accuracy were assessed. participants made global memory predictions and item-by-item memory predictions in a single experimental task. Metacognitive accuracy was evaluated with correlational and more traditional difference-score measures. Difference-score measures were found, in some cases, to be sensitive to level of recall performance. Correlational techniques revealed that older adults monitored learning effectively. Relative to younger adults, they showed equally accurate immediate judgments of learning (JOLs), produced an equivalent delayed-JOL effect, and showed equivalent upgrading in the accuracy of their global prediction from before to after study of test materials.

Beyond Autoregressive Models: Some Implications of the Trait-State Distinction for the Structural Modeling of Developmental Change.

The use of structural modeling techniques to fit change concepts, including developmental ones, to repeated-measurements data has been rather firmly but uncritically wedded to autoregressive model specifications. The uncritical application of an autoregressive specification to repeated measures does not take into account subtleties of conceptions of stability and change (e.g., the trait-state distinction) that are now recognized in the behavioral research literature. We review the basic distinction between trait and state and examine the implications of the different possibilities for modeling developmental phenomena. The arguments are illustrated with empirical examples.

Short-term longitudinal change in cognitive performance in later life

Changes in mean performance on memory, information processing, and intellectual ability tasks over a 3-year period were examined. The sample consisted of 328 community-dwelling men and women (from an original sample of 484 individuals) aged 55-86 years. Ss completed tasks yielding measures of verbal processing time, working memory, implicit memory, vocabulary, verbal fluency, world knowledge, reading comprehension, word recall, and text recall. The results showed significant average decline on working memory, verbal fluency, and world knowledge. There were also interactions for 2 processing time measures and working memory, showing greater decline in the earlier-born cohort group than in the later-born cohort group. A step-down analysis revealed that covarying declines in other variables, including processing time, did not eliminate significant declines in working memory, verbal fluency, and world knowledge.

Latent Change Models of Adult Cognition: Are Changes in Processing Speed and Working Memory Associated With Changes in Episodic Memory?

The authors used 6-year longitudinal data from the Victoria Longitudinal Study (VLS) to investigate individual differences in amount of episodic memory change. Latent change models revealed reliable individual differences in cognitive change. Changes in episodic memory were significantly correlated with changes in other cognitive variables, including speed and working memory. A structural equation model for the latent change scores showed that changes in speed and working memory predicted changes in episodic memory, as expected by processing resource theory. However, these effects were best modeled as being mediated by changes in induction and fact retrieval. Dissociations were detected between cross-sectional ability correlations and longitudinal changes. Shuffling the tasks used to define the Working Memory latent variable altered patterns of change correlations.