List and text recall differ in their predictors: replication over samples and time

Examination of discrepancies between subjective and objective memory with latent factors of the geriatric depression scale

OBJECTIVE

The purpose of the present study was to examine whether multiple constructs of depressive symptoms explained discrepancies between subjective (SM) and objective memory (OM) in older adulthood.

METHOD

A sub-sample (Range: 65-98 years, N = 606) of the 2000 Wave Panel 3 of the Long Beach Longitudinal Study was used to explore underlying latent factors within the Geriatric Depression Scale (GDS).

RESULTS

Four GDS factors were identified (Dysphoria, Vigor/Withdrawal, Cognitive Concerns, and Agitation); the factor solution was tested in a confirmatory factor analysis. Mechanisms of the GDS factors on SM and OM were tested by using structural equation modeling. Dysphoria negatively predicted OM, but not SM, suggesting that people who scored high in Dysphoria might not sense their memory failures although they obviously performed poorly in OM. Cognitive concerns negatively predicted SM, but not OM, suggesting that cognitive concerns were not influential for OM, but negatively affected one's evaluation of SM.

CONCLUSION

The study results have clinical implications since such relationships can be concealed while assessing depressive symptoms as a single GDS factor. Thus, the patterns of the GDS factors, SM, and OM derived from this study can be very useful for clinicians who conduct assessments on depressive symptoms and memory failures.

Contributions of Personality and Depressive Symptoms on Subjective and Objective Memory

This study aimed to examine whether individual differences in personality and multifaceted depression explain discrepancies between subjective memory (SM) and objective memory (OM), and whether these relationships varied as a function of gender. Structural equation modeling was used to test these relationships in a group of older adults (65–98 years, N = 606) from the 2000 Wave Panel 3 of the Long Beach Longitudinal Study. Women outperformed men on OM, reporting less frequent memory failures. Dysphoria and openness predicted OM, yet not SM. Cognitive concerns, neuroticism, and conscientiousness predicted SM but not OM. The personality and Geriatric Depression Scale (GDS) factors relevant for SM differed from those for OM, with the GDS factors showing a stronger impact. Overall, discrepancies between SM and OM may be partially explained by the varying impact of the GDS and personality factors, as both provide differential utility in understanding SM and OM differences in older adulthood.

The Effects of Home-Based Cognitive Training on Verbal Working Memory and Language Comprehension in Older Adulthood

Effective language understanding is crucial to maintaining cognitive abilities and learning new information through adulthood. However, age-related declines in working memory (WM) have a robust negative influence on multiple aspects of language comprehension and use, potentially limiting communicative competence. In the current study (N = 41), we examined the effects of a novel home-based computerized cognitive training program targeting verbal WM on changes in verbal WM and language comprehension in healthy older adults relative to an active component-control group. Participants in the WM training group showed non-linear improvements in performance on trained verbal WM tasks. Relative to the active control group, WM training participants also showed improvements on untrained verbal WM tasks and selective improvements across untrained dimensions of language, including sentence memory, verbal fluency, and comprehension of syntactically ambiguous sentences. Though the current study is preliminary in nature, it does provide initial promising evidence that WM training may influence components of language comprehension in adulthood and suggests that home-based training of WM may be a viable option for probing the scope and limits of cognitive plasticity in older adults.

To Switch or Not to Switch: Role of Cognitive Control in Working Memory Training in Older Adults

It is currently not known what are the best working memory training strategies to offset the age-related declines in fluid cognitive abilities. In this randomized clinical double-blind trial, older adults were randomly assigned to one of two types of working memory training – one group was trained on a predictable memory updating task (PT) and another group was trained on a novel, unpredictable memory updating task (UT). Unpredictable memory updating, compared to predictable, requires greater demands on cognitive control (Basak and Verhaeghen, 2011a). Therefore, the current study allowed us to evaluate the role of cognitive control in working memory training. All participants were assessed on a set of near and far transfer tasks at three different testing sessions – before training, immediately after the training, and 1.5 months after completing the training. Additionally, individual learning rates for a comparison working memory task (performed by both groups) and the trained task were computed. Training on unpredictable memory updating, compared to predictable, significantly enhanced performance on a measure of episodic memory, immediately after the training. Moreover, individuals with faster learning rates showed greater gains in this episodic memory task and another new working memory task; this effect was specific to UT. We propose that the unpredictable memory updating training, compared to predictable memory updating training, may a better strategy to improve selective cognitive abilities in older adults, and future studies could further investigate the role of cognitive control in working memory training.

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.

Modelling longitudinal changes in older adults' memory for spoken discourse: findings from the ACTIVE cohort

Episodic memory shows substantial declines with advancing age, but research on longitudinal trajectories of spoken discourse memory (SDM) in older adulthood is limited. Using parallel process latent growth curve models, we examined 10 years of longitudinal data from the no-contact control group (N = 698) of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomised controlled trial in order to test (1) the degree to which SDM declines with advancing age, (2) the predictors of these age-related declines and (3) the within-person relationship between longitudinal changes in SDM and longitudinal changes in fluid reasoning and verbal ability over 10 years, independent of age. Individuals who were younger, were White, had more years of formal education, were male and had better global cognitive function and episodic memory performance at baseline demonstrated greater levels of SDM on average. However, only age at baseline uniquely predicted longitudinal changes in SDM, such that declines accelerated with greater age. Independent of age, within-person decline in reasoning ability over the 10-year study period was substantially correlated with decline in SDM (r = .87). An analogous association with SDM did not hold for verbal ability. The findings suggest that longitudinal declines in fluid cognition are associated with reduced spoken language comprehension. Unlike findings from memory for written prose, preserved verbal ability may not protect against developmental declines in memory for speech.

Mediating effect of executive function on memory in normal aging adults

OBJECTIVE

We hypothesize that the effect of aging on memory is mediated by executive function.

METHODS

Two hundred and thirty healthy adults (101 male, 129 female) were recruited for the study. We used a promising, newly developed, computerized neuropsychological test for the measurement of executive function and memory. The data were analyzed using structural equation modeling and path analysis.

RESULTS

The full mediation model showed a good fit to the data. However, chi-squared (χ(2)) tests for model comparison indicated that the partial mediation model better fits our data. Thus, the partial mediation model was used as the final model. In terms of auditory-verbal memory, the effect of aging on memory was fully mediated by executive function. However, visuo-spatial memory was significantly affected both indirectly (through executive function) and directly (by aging). Gender differences were not significant in this model.

CONCLUSION

This study demonstrated the importance of executive function in the memory functioning of normal aging adults. It is noteworthy that modality differences were found between auditory-verbal and visuo-spatial memory. Aging is not the only factor that drives memory decline, and its direct, adverse effect on memory was more prominent in the visuo-spatial memory task than auditory-verbal memory task. Since performance in both modalities is fully or partially mediated by executive function, it is important to train normal aging adults in executive control skills, such as planning, strategy formation, and rapid decision making.