Cognitive profiles in older males and females

Cognitive reserve moderates the effect of COVID-19 on cognition: A systematic review and meta-analysis of individual participant data

Elucidating the factors that mitigate the effects of COVID-19 on cognitive function offers important insights for public health policy and intervention. This systematic review and individual participant data (IPD) meta-analysis assesses cognitive reserve (CR) as a potential moderator of post-COVID-19 cognitive dysfunction (PCCD). Under PRISMA-IPD guidelines, data searches were conducted via PubMed, PsycINFO, Scopus, and Embase, up to January 2023. Eligible studies included at least one cognitive assessment, CR proxy, and disease severity indicator. Of 5604 studies, 87 were eligible (10,950 COVID-19 cases; 78,305 controls), and IPD was obtained for 29 datasets (3919 COVID-19 cases; 8267 controls). Three-level random-effects meta-analyses indicated that CR had a moderate positive association (rsp =.29), and COVID-19 severity had a small negative association (rsp = -.07) with cognitive outcomes. These effects were moderated by a significant within-study interaction. Cognitive deficits following COVID-19 were 33 % smaller among high CR individuals, and 33 % greater among low CR individuals, relative to those with average CR. Population-based initiatives promoting reserve-building behaviors may alleviate the PCCD-related public health burden. REVIEW REGISTRATION: PROSPERO registration number: CRD42022360670.

Sex differences in cognitive performance persist into your 80s

BACKGROUND

Sex differences in cognitive performance have been extensively documented. Understanding the underlying factors contributing to sex differences in older adults is imperative to promote healthy cognitive aging. Sex hormones, estrogens, and testosterone have been suggested to be associated with cognition. Nevertheless, there is a scarcity of studies investigating the sex difference in cognitive performance and the contribution of gonadal hormones in older adults. Hence, the current study aimed to investigate sex differences in cognitive performance and elucidate the association between gonadal hormones and cognitive performance in 80+ -year-olds.

METHODS

Using confirmatory factor analysis in a sample of 131 older adults (aged 80 to 92 years), 17 cognitive performance measures were divided into two cognitive components: executive functioning and memory. Subsequently, mediation analyses were conducted to determine the direct effect of sex and the indirect effect mediated by gonadal hormones on executive functioning and memory.

RESULTS

Females outperformed males in executive functioning and memory. However, gonadal hormones did not mediate the sex effect on cognitive performance. Estrogen levels significantly predicted executive functioning but not memory. Testosterone levels did neither predict executive functioning nor memory.

CONCLUSION

Our study confirms enduring sex differences in memory and executive function, even among individuals aged 80 and above. Current gonadal hormone levels do not mediate these differences. While estrogen may predict executive function, its influence does not explain the sex differences. These findings underscore the complex nature of cognitive disparities between sexes in older age, warranting further investigation into underlying mechanisms.

Biological sex, microglial signaling pathways, and radiation exposure shape cortical proteomic profiles and behavior in mice

Patients receiving cranial radiation therapy experience tissue damage and cognitive deficits that severely decrease their quality of life. Experiments in rodent models show that these adverse neurological effects are in part due to functional changes in microglia, the resident immune cells of the central nervous system. Increasing evidence suggests that experimental manipulation of microglial signaling can regulate radiation-induced changes in the brain and behavior. Furthermore, many studies show sex-dependent neurological effects of radiation exposure. Despite this, few studies have used both males and females to explore how sex and microglial function interact to influence radiation effects on the brain. Here, we used a system levels approach to examine how deficiencies in purinergic and fractalkine signaling, two important microglial signaling pathways, impact brain proteomic and behavioral profiles in irradiated and control male and female mice. We performed a comprehensive analysis of the cortical proteomes from irradiated and control C57BL/6J, P2Y12-/-, and CX3CR1-/- mice of both sexes using multiple bioinformatics methods. We identified distinct proteins and biological processes, as well as behavioral profiles, regulated by sex, genotype, radiation exposure, and their interactions. Disrupting microglial signaling, had the greatest impact on proteomic expression, with CX3CR1-/- mice showing the most distinct proteomic profile characterized by upregulation of CX3CL1. Surprisingly, radiation exposure caused relatively smaller proteomic changes in glial and synaptic proteins, including Rgs10, Crybb1, C1qa, and Hexb. While we observed some radiation effects on locomotor behavior, biological sex as well as loss of P2Y12 and CX3CR1 signaling had a stronger influence on locomotor outcomes in our model. Lastly, loss of P2Y12 and CX3CR1 strongly regulated exploratory behaviors. Overall, our findings provide novel insights into the molecular pathways and proteins that are linked to P2Y12 and CX3CR1 signaling, biological sex, radiation exposure, and their interactions.

The effectiveness of emotion-oriented approaches on psychological outcomes and cognitive function in older adults: A meta-analysis of randomised controlled trials

Background

Emotion-oriented approaches have demonstrated effectiveness in the care of the elderly. However, related studies have reported conflicting results. We aimed to explore the pooled effect of emotion-oriented approaches on the psychological outcomes and cognitive function of older adults through a meta-analysis of randomised controlled trials (RCTs).

Methods

We searched eight databases - CINAHL, Cochrane, Embase, Ovid MEDLINE, PsycINFO, PubMed, Scopus, and Web of Science - for RCTs from inception to 11 January 2024. Participants aged 60 years or older who received emotion-oriented approaches as the intervention, and reported outcomes of interest in the studies were included. The primary outcome was psychological outcomes (depression, self-esteem, life satisfaction and loneliness), and the secondary outcome was global cognitive function. The pooled effect size was computed in comprehensive meta-analysis 3.0 software using Hedges' g (g) with random-effects model. Furthermore, heterogeneity was assessed through Cochrane's Q and I2 tests. The quality of the included studies was evaluated using the Cochrane Risk of Bias tool. To explore potential sources of heterogeneity, moderator analyses were conducted.

Results

We included 37 RCTs and found that emotion-oriented approaches improve depression (g = -0.82, 95% CI = -1.08, -0.56), self-esteem (g = 0.98, 95% CI = 0.31, 1.64), life satisfaction (g = 0.63, 95% CI = 0.37, 0.88), loneliness (g = -2.22, 95% CI = -3.80, -0.64) and global cognitive function (g = 0.34, 95% CI = 0.19, 0.49) in older adults. We also observed significant follow-up effects on depression (g = -1.40, 95% CI = -2.45, -0.34) and loneliness (g = -3.48, 95% CI = 6.02, -0.94).

Conclusions

Emotion-oriented approaches are promising interventions in improving psychological outcomes and global cognitive function in older adults. Health care workers should receive training to promote and integrate emotion-oriented approaches into routine care of older adults emphasising the importance of collaborative efforts among health care professionals and caregivers to ensure holistic care delivery.

Sex modulated the relationship between trait approach motivation and decision-making

It has been observed that one's Behavioral Approach System (BAS) can have an effect on decision-making under uncertainty, although the results have been mixed. To discern the underlying neural substrates, we hypothesize that sex may explain the conflicting results. To test this idea, a large sample of participants was studied using resting state fMRI, utilizing fractional Amplitude of Low Frequency Fluctuations (fALFF) and Resting-State Functional Connectivity (rsFC) techniques. The results of the Iowa Gambling Task (IGT) revealed an interaction between sex and BAS, particularly in the last 60 trials (decision-making under risk). Males with high BAS showed poorer performance than those with low BAS. fALFF analysis showed a significant interaction between BAS group and sex in the left superior occipital gyrus, as well as the functional connectivity between this region and the left ventrolateral prefrontal cortex. Additionally, this functional connectivity was further positively correlated with male performance in the IGT, particularly in the decision-making under risk stage. Furthermore, it was found that the functional connectivity between left ventrolateral prefrontal cortex and left superior occipital gyrus could mediate the relationship between BAS and decision-making in males, particularly in the decision-making under risk stage. These results suggest possible sex-based differences in decision-making, providing an explanation for the inconsistent results found in prior research. Since the research was carried out exclusively with Chinese university students, it is essential to conduct further studies to investigate whether the findings can be generalized.

Differential predictability of cognitive profiles from brain structure in older males and females

Structural brain imaging parameters may successfully predict cognitive performance in neurodegenerative diseases but mostly fail to predict cognitive abilities in healthy older adults. One important aspect contributing to this might be sex differences. Behaviorally, older males and females have been found to differ in terms of cognitive profiles, which cannot be captured by examining them as one homogenous group. In the current study, we examined whether the prediction of cognitive performance from brain structure, i.e. region-wise grey matter volume (GMV), would benefit from the investigation of sex-specific cognitive profiles in a large sample of older adults (1000BRAINS; N = 634; age range 55-85 years). Prediction performance was assessed using a machine learning (ML) approach. Targets represented a) a whole-sample cognitive component solution extracted from males and females, and b) sex-specific cognitive components. Results revealed a generally low predictability of cognitive profiles from region-wise GMV. In males, low predictability was observed across both, the whole sample as well as sex-specific cognitive components. In females, however, predictability differences across sex-specific cognitive components were observed, i.e. visual working memory (WM) and executive functions showed higher predictability than fluency and verbal WM. Hence, results accentuated that addressing sex-specific cognitive profiles allowed a more fine-grained investigation of predictability differences, which may not be observable in the prediction of the whole-sample solution. The current findings not only emphasize the need to further investigate the predictive power of each cognitive component, but they also emphasize the importance of sex-specific analyses in older adults.

The Auditory Consonant Trigram (ACT) Test: A norm updating study for university students

The Auditory Consonant Trigram (ACT) Test is accepted as a pure measurement of verbal working memory, but its norm study and psychometric properties have not been sufficiently researched. This study aims to update the norm data of the ACT, validity and reliability studies of which have been previously conducted on an adult Turkish sample, on a broader young sample and in a way that would end some methodological limitations. For this purpose, the data is collected from 304 voluntary healthy young adults (aged 18-26, 152 females-152 males). According to the results, a difference is found among all delay intervals. While the test scores decrease in females as delay interval increases, there is no difference in males between the delay intervals of 9 and 18 sec. While there is no difference between the genders for very short delay intervals (0-3 sec), males show a more successful performance than females as the delay interval increases (9-18 sec). Males are also more successful than females in terms of total test scores of the ACT. In this respect, it is concluded that the ACT measurement of working memory with a total score reliability coefficient of 0.75 is reliable.

Intensive assessment of executive functions derived from performance in cognitive training games

Traditional neuropsychological tests accurately describe the current cognitive state but fall short to characterize cognitive change over multiple short time periods. We present an innovative approach to remote monitoring of executive functions on a monthly basis, which leverages the performance indicators from self-administered computerized cognitive training games (NUP-EXE). We evaluated the measurement properties of NUP-EXE in N = 56 individuals (59% women, 60-80 years) at increased risk of Alzheimer's disease (APOE-ϵ4 carriers with subjective cognitive decline) who completed a 12-month multimodal intervention for preventing cognitive decline. NUP-EXE presented good psychometric properties and greater sensitivity to change than traditional tests. Improvements in NUP-EXE correlated with improvements in functionality and were affected by participants' age and gender. This novel data collection methodology is expected to allow a more accurate characterization of an individual's response to a cognitive decline preventive intervention and to inform development of outcome measures for a new generation of intervention trials.

Characterization of the angular gyrus in an older adult population: a multimodal multilevel approach

The angular gyrus (AG) has been associated with multiple cognitive functions, such as language, spatial and memory functions. Since the AG is thought to be a cross-modal hub region suffering from significant age-related structural atrophy, it may also play a key role in age-related cognitive decline. However, the exact relation between structural atrophy of the AG and cognitive decline in older adults is not fully understood, which may be related to two aspects: First, the AG is cytoarchitectonically divided into two areas, PGa and PGp, potentially sub-serving different cognitive functions. Second, the older adult population is characterized by high between-subjects variability which requires targeting individual phenomena during the aging process. We therefore performed a multimodal (gray matter volume [GMV], resting-state functional connectivity [RSFC] and structural connectivity [SC]) characterization of AG subdivisions PGa and PGp in a large older adult population, together with relations to age, cognition and lifestyle on the group level. Afterwards, we switched the perspective to the individual, which is especially important when it comes to the assessment of individual patients. The AG can be considered a heterogeneous structure in of the older brain: we found the different AG parts to be associated with different patterns of whole-brain GMV associations as well as their associations with RSFC, and SC patterns. Similarly, differential effects of age, cognition and lifestyle on the GMV of AG subdivisions were observed. This suggests each region to be structurally and functionally differentially involved in the older adult's brain network architecture, which was supported by differential molecular and genetic patterns, derived from the EBRAINS multilevel atlas framework. Importantly, individual profiles deviated considerably from the global conclusion drawn from the group study. Hence, general observations within the older adult population need to be carefully considered, when addressing individual conditions in clinical practice.

The limitations of large-scale volunteer databases to address inequalities and global challenges in health and aging

Large-scale volunteer databanks (LSVD) have emerged from the recognized value of cohorts, attracting substantial funding and promising great scientific value. A major focus is their size, with the implicit and sometimes explicit assumption that large size (thus power) creates generalizability. We contend that this is open to challenge. In the context of aging and age-related disease research, LSVD typically have limitations such as healthy volunteer, white ethnicity and high-education biases, and they omit early and late life stages critical for understanding aging. Their outputs are heavily focused on biomedical pathways of single chronic diseases. LSVD outputs increasingly dominate the funding and the publication landscapes. This Perspective discusses LSVD limitations and calls for more transparent reporting in LSVD research, as well as a greater reflection on the value of LSVD in relation to resources consumed. We invite funders and researchers to examine whether LSVD do actually contribute knowledge needed for our acute global health challenges including inequalities.

The effect of risk factors on cognition in adult cochlear implant candidates with severe to profound hearing loss

Hearing loss has been identified as a major modifiable risk factors for dementia. Adult candidates for cochlear implantation (CI) represent a population at risk of hearing loss-associated cognitive decline. This study investigated the effect of demographics, habits, and medical and psychological risk factors on cognition within such a cohort. Data from 34 consecutive adults with post-lingual deafness scheduled for CI were analyzed. Pure tone audiometry (PTA4) and Speech Discrimination Score (SDS) were recorded. The Repeatable Battery for Assessment of Neuropsychological Status for Hearing impaired individuals (RBANS-H) was used to measure cognition. Demographics (sex, age, years of education), habits (smoking, alcohol intake, physical inactivity), and medical factors (hypertension, diabetes, traumatic brain injury) were evaluated. Depression was measured using the Hospital Anxiety and Depression Scale (HADS), and social inhibition with the Type D questionnaire (DS14). All participants (mean age 62 ± 15 years) suffered from severe to profound hearing loss (PTA4:129 ± 60 dB; SDS:14 ± 24%). The mean RBANS-H total score was 83 ± 16. Participants reported a mean of years of formal education of 12 ± 5 years. The prevalence of habits and medical risk factors was: physical inactivity (29%), body mass index >30 (28%), traumatic brain injury (25%), hypertension (24%), heavy alcohol consumption (13%), smoking (13%), and diabetes (0%). Regarding psychological factors, the mean scores of social inhibition and depression were 10 ± 6 and 6 ± 5, respectively. The number of years of education was significantly correlated with the RBANS-H total score (p < 0.001), and with the domains “Immediate memory” (p = 0.003), “Visuospatial/constructional” (p < 0.001), and “Attention” (p < 0.001). The mean RBANS-H total score in participants who had university studies or higher level (12/34) was 97 ± 9, with the remaining participants reporting a mean score of 75 ± 15. Men performed better in the “Visuospatial/constructional” (p = 0.008). Physical inactivity was associated with lower scores in the “Delayed memory” (p = 0.031); hypertension correlated with lower RBANS-H total scores (p = 0.025) and “Attention” (p = 0.006). Depression and social inhibition were negatively correlated with RBANS-H total score and with the “Immediate memory,” “Visuospatial/constructional,” and “Attention” (all p < 0.05). In adults with late-onset deafness scheduled to CI, educational level has a significant effect. Additionally, sex, physical inactivity, hypertension, and psychological traits of social inhibition and depression may also influence cognitive status. Long-term studies with more participants would enable us better understand the effects different risk factors on cognitive status.

Differential Role of Sex and Age in the Synaptic Transmission of Degus (Octodon degus)

Octodon degus are a diurnal long-lived social animal widely used to perform longitudinal studies and complex cognitive tasks to test for physiological conditions with similitude in human behavior. They show a complex social organization feasible to be studied under different conditions and ages. Several aspects in degus physiology demonstrated that these animals are susceptible to environmental conditions, such as stress, fear, feeding quality, and isolation. However, the relevance of these factors in life of this animal depends on sex and age. Despite its significance, there are few studies with the intent to characterize neurological parameters that include these two parameters. To determine the basal neurophysiological status, we analyzed basic electrophysiological parameters generated during basal activity or synaptic plasticity in the brain slices of young and aged female and male degus. We studied the hippocampal circuit of animals kept in social ambient in captivity under controlled conditions. The study of basal synaptic activity in young animals (12–24 months old) was similar between sexes, but female degus showed more efficient synaptic transmission than male degus. We found the opposite in aged animals (60–84 months old), where male degus had a more efficient basal transmission and facilitation index than female degus. Furthermore, female and male degus develop significant but not different long-term synaptic plasticity (LTP). However, aged female degus need to recruit twice as many axons to evoke the same postsynaptic activity as male degus and four times more when compared to young female degus. These data suggest that, unlike male degus, the neural status of aged female degus change, showing less number or functional axons available at advanced ages. Our data represent the first approach to incorporate the effect of sex along with age progression in basal neural status.