Episodic Memory and Executive Function Are Differentially Affected by Retests but Similarly Affected by Age in a Longitudinal Study of Normally-Aging Older Adults

Does Perceived Generativity Mediate the Association Between Optimism and Cognitive Function Over Time? Findings from Midlife in the United States Study

Cognitive function is a vital component of healthy aging. However, whether a persistently high optimism benefits late-life cognitive function is debatable. The current study examined associations between high optimism status, perceived generativity, and cognitive functions across adulthood. Data were from waves 2 and 3 (2004-14) of the Midlife in the United States study. We used structural equation modeling to examine whether participants' (N = 2,205; Mage = 65 ± 11) persistent high optimism predicts better cognitive functions over time, compared to high optimism at only one time-point or not at all while controlling for covariates; we also examined whether individuals' perceived generativity mediates the above association. The findings revealed that persistent high optimism was significantly associated with better episodic memory and executive function. Further, perceived generativity positively mediated the association between persistent high optimism and episodic memory. Future research should examine mechanisms for potential aspects of high optimism and perceived generativity on late-life cognitive performances.

Protective roles of meditation practice and self-esteem on cognitive functions over time: findings from the Midlife in the United States study

BACKGROUND

Cognitive function is an important component of healthy ageing. However, it is unclear whether relaxation/meditation practices provide cognitive benefits, particularly in midlife and early late life. Meditative practices are associated with higher self-esteem, and self-esteem serves as a general protective factor for many health outcomes. The current study examines associations between meditation practice, self-esteem, and change over 10 years in midlife cognitive performance.

METHODS

Data were from waves 2 (2003-2004) and 3 (2013-2014) of the Midlife in the United States (MIDUS) study. We used structural equation modelling to examine whether persistent meditation practice at both waves or episodic practice at one wave is associated with better cognitive function over 10 years, compared to no meditation practice, while controlling for prior cognitive function and covariates (baseline socio-demographics, health, and functional status). Additionally, we assessed if self-esteem mediates the above associations.

RESULTS

We included 2168 individuals (Mage  = 65 ± 11). After controlling for covariates, the findings revealed that persistent meditation practice in both waves was associated with significantly less decline in episodic memory; however, no such effects were found for executive function. Further, although participants' higher self-esteem was significantly associated with less decline in executive function and episodic memory, it did not mediate the associations between meditation practice and cognitive functions.

CONCLUSIONS

While both persistent meditation practice and self-esteem have associations with cognitive outcomes for middle-aged and older adults in MIDUS, self-esteem as a mediator was not supported. Thus, future investigations should examine mechanisms that underlie these protective factors on cognitive performances across adulthood.

Is Use of Psychedelic Drugs a Risk or Protective Factor for Late-Life Cognitive Decline?

Objectives: Common age-related health conditions can lead to poor mental health outcomes and deteriorate cognition. Additionally, commonly prescribed medications for various mental/physical health conditions may cause adverse reactions, especially among older adults. Psychedelic therapy has shown positive impacts on cognition and has been successful in treating various mental health problems without long-lasting adversities. The current study examines the association between psychedelic drug usage and cognitive functions in middle-aged and older adults. Methods: Data were from wave 3 (2013-2014) of the Midlife in the United States (MIDUS) study. We used multiple linear regression models examining associations between psychedelic usage and cognitive functions, controlling for covariates of sociodemographic and health factors. Results: We included 2,503 individuals (Mage = 64 ± 11). After controlling for covariates, the finding revealed that psychedelic usage was independently associated with more favorable changes in executive function (β = .102, SE = 0.047, p = .031) and less depressive symptoms (β = -.090, SE = 0.021, p < .001). The same effect was not found for episodic memory (β = .039, SE = 0.066, p = .553). Discussion: Addressing the mental health implications of physical health conditions in older adults are vital for preventing neurocognitive deterioration, prolonging independence, and improving the quality of life. More longitudinal research is essential utilizing psychedelics as an alternative therapy examining late-life cognitive benefits.

Impact of Optimism on Cognitive Performance of People Living in Rural Area: Findings From a 20-Year Study in US Adults

Objectives: Mid- or early-late-life cognitive function is an indicator for developing late-life dementia. However, it is still unclear whether rural/urban living contexts provide cognitive benefits across adulthood. Further, higher optimism serves as a general protective factor for many health outcomes. The present study examines associations between rurality/urbanicity, optimism, and change in mid/late-life cognitive functions over time. Methods: Data were from waves 1 to 3 (1995-2015) of the Midlife in the United States (MIDUS) study (N = 2,507). Structural equation models examine whether long-term rural living across both waves (1-2) or intermittent rural living at one wave is associated with better cognitive function over 20 years, compared to no rural living, while controlling for prior cognitive function and covariates (baseline socio-demographics, health, and functional status). Additionally, we assessed if optimism mediates the above associations. Results: After controlling for covariates, long-term rural living (waves 1-2) was indirectly (through less optimism) associated with significantly lower levels of cognitive executive function and episodic memory in wave 3. Conclusions: While long-term rural living and cognitive outcomes have no direct association for MIDUS middle-aged and older adults, mediating roles of optimism in these associations were evident. Future investigations could examine mechanisms that underlie these risk/protective factors on late-life cognition.

Executive function and episodic memory composite scores in older adults: relations with sex, mood, and subjective sleep quality

Executive function and episodic memory processes are particularly vulnerable to aging. We sought to learn the degree to which sex, mood, and subjective sleep quality might be related to executive function and episodic memory composite scores in community-dwelling older adults. We replicated Glisky and colleagues' two-factor (i.e., executive function [N=263] versus episodic memory [N=151]) structure, and found that it did not significantly differ between males and females. Moderation analyses revealed no interactions between sex, mood, and sleep in predicting either composite score. However, females significantly outperformed males on the episodic memory composite, and on all the individual tests comprising it. Ours is the first study to look at sex differences in this battery's factor structure and its potential relations with mood and sleep. Future longitudinal studies in both healthy and clinical populations will help us further probe the possible influence of these variables on executive function and episodic memory in aging.

Misinterpreting cognitive change over multiple timepoints: When practice effects meet age-related decline

OBJECTIVE

Practice effects (PE) on cognitive testing have been shown to delay detection of impairment and impede our ability to assess change. When decline over time is expected, as with older adults or progressive diseases, failure to adequately address PEs may lead to inaccurate conclusions because PEs artificially boost scores while pathology- or age-related decline reduces scores. Unlike most methods, a participant-replacement approach can separate pathology- or age-related decline from PEs; however, this approach has only been used across two timepoints. More than two timepoints make it possible to determine if PEs level out after the first follow-up, but it is analytically challenging because individuals may not be assessed at every timepoint.

METHOD

We examined 1,190 older adults who were cognitively unimpaired (n = 809) or had mild cognitive impairment (MCI; n = 381). Participants completed six neuropsychological measures at three timepoints (baseline, 12-month, 24-month). We implemented a participant-replacement method using generalized estimating equations in comparisons of matched returnees and replacements to calculate PEs.

RESULTS

Without accounting for PEs, cognitive function appeared to improve or stay the same. However, with the participant-replacement method, we observed significant PEs within both groups at all timepoints. PEs did not uniformly decrease across time; some-specifically on episodic memory measures-continued to increase beyond the first follow-up.

CONCLUSION

A replacement method of PE adjustment revealed significant PEs across two follow-ups. As expected in these older adults, accounting for PEs revealed cognitive decline. This, in turn, means earlier detection of cognitive deficits, including progression to MCI, and more accurate characterization of longitudinal change. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Mental rotation, episodic memory, and executive control: Possible effects of biological sex and oral contraceptive use

Oral contraceptives (OCs) are one of the most common forms of hormonal birth control. A small literature suggests that OC use may affect visuospatial ability, episodic memory, and executive control. However, previous studies have been criticized for small sample sizes and the use of different, single cognitive tests. We investigated the degree to which biological sex and OC use might affect individual mental rotation, episodic memory, and executive control in a large sample of healthy, young adults (N = 155, including 52 OC users, 53 naturally cycling females, and 50 males) tested individually over videoconference. To measure cognition, we used a set of neuropsychological tasks inspired by Glisky and colleagues' two-factor episodic memory and executive control battery, from which two composite scores (based on principal component analysis) were derived for each participant. Our pre-registered analysis revealed a clear female advantage in episodic memory, independent of OC use. In an exploratory analysis, gist memory was elevated in OC users. Interestingly, we found no significant sex-related differences nor effects of OC use on mental rotation or executive control. Duration of OC use was also not related to any of our cognitive measures. These results suggest that the use of combined, monophasic OCs does not lead to many significant changes in cognition in young adults, although young females overall may have better episodic memory than young males. Additional studies, including longitudinal designs and looking in more detail at the menstrual cycle and OC use history, will further clarify the effects of different types of OCs and their duration of use on different aspects of cognition.

Grip strength, gait speed, and trajectories of cognitive function in community-dwelling older adults: A prospective study

Introduction

This study investigated whether grip strength and gait speed predict cognitive aging trajectories and examined potential sex-specific associations.

Methods

Community-dwelling older adults (n = 19,114) were followed for up to 7 years, with regular assessment of global function, episodic memory, psychomotor speed, and executive function. Group-based multi-trajectory modeling identified joint cognitive trajectories. Multinomial logistic regression examined the association of grip strength and gait speed at baseline with cognitive trajectories.

Results

High performers (14.3%, n = 2298) and low performers (4.0%, n = 642) were compared to the average performers (21.8%, n = 3492). Grip strength and gait speed were positively associated with high performance and negatively with low performance (P-values < 0.01). The association between grip strength and high performance was stronger in women (interaction P < 0.001), while gait speed was a stronger predictor of low performance in men (interaction P < 0.05).

Discussion

Grip strength and gait speed are associated with cognitive trajectories in older age, but with sex differences.

Highlights

There is inter-individual variability in late-life cognitive trajectories.Grip strength and gait speed predicted cognitive trajectories in older age.However, sex-specific associations were identified.In women, grip strength strongly predicted high, compared to average, trajectory.In men, gait speed was a stronger predictor of low cognitive performance trajectory.