Executive functions in men and postmenopausal women

Investigation of the Effects of Home-Based Exercise and Cognitive Training on Cognitive and Physical Functions in Cardiac Patients: The COVEPICARDIO Study Protocol of a Randomized Clinical Trial

Introduction: During the COVID-19 pandemic, confinement measures are likely to produce collateral damage to health (stress, confusion, anxiety), especially in frail individuals and those living with cardiovascular disease (CVD). In cardiac patients in particular, these measures dramatically increase the level of physical inactivity and sedentary lifestyle, which can decrease cardiorespiratory capacity and increase the risk of acute events, rehospitalization, and depressive syndromes. Maintaining a minimum level of physical activity and cognitive stimulation during the COVID-19 crisis is essential for cardiac patients. This study is designed to document the effects of 6 months of home-based physical exercise alone or combined with cognitive training on cognitive and physical functions in patients with CVD over 50 years old.

Methods and Analysis: 122 patients (>50 years old) with stable CVD and no contraindication to perform physical exercise training will be recruited and randomly assigned to one of the 2 following arms: (1) Home-based physical exercise alone, (2) Home-based physical exercise combined with cognitive training. The intervention lasts 6 months, with remote assessments performed prior to, mid and post-training. A follow-up 6 months after the end of the intervention (12 month) is also proposed. The primary outcome is cognition, including general functioning (Montreal Cognitive Assessment (MoCA) score), as well as performances on measures of executive functions, processing speed, and episodic memory. The secondary outcome is physical performance, including balance, gait and mobility, leg muscle strength and estimated cardiorespiratory fitness. Tertiary outcomes include mood, anxiety, and health-related quality of life as assessed by self-reported online questionnaires.

Discussion: With the COVID-19 crisis, there is a critical need for remote exercise and cognitive training, and to further investigate this topic, in particular for cardiac patients. The present context can be viewed as an opportunity to perform a major shift from center-based programs to home-based physical exercise. This is especially important to reach out to older adults living in remote areas, where access to such interventions is limited.

ClinicalTrials.gov: [https://clinicaltrials.gov/ct2/show/NCT04661189], NCT04661189.

Sex moderations in the relationship between aortic stiffness, cognition, and cerebrovascular reactivity in healthy older adults

It is well established that sex differences exist in the manifestation of vascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex.

COVEPIC (Cognitive and spOrt Virtual EPIC training) investigating the effects of home-based physical exercise and cognitive training on cognitive and physical functions in community-dwelling older adults: study protocol of a randomized single-blinded clinical trial

BACKGROUND

In the context of the COVID-19 pandemic, lockdown and social distancing measures are applied to prevent the spread of the virus. It is well known that confinement and social isolation can have a negative impact on physical and mental health, including cognition. Physical activity and cognitive training can help enhance older adults' cognitive and physical health and prevent the negative collateral impacts of social isolation and physical inactivity. The COVEPIC study aims to document the effects of 6 months of home-based physical exercise alone versus home-based physical exercise combined with cognitive training on cognitive and physical functions in adults 50 years and older.

METHODS

One hundred twenty-two healthy older adults (> 50 years old) will be recruited from the community and randomized to one of the two arms for 6 months: (1) home-based physical exercises monitoring alone and (2) combined physical exercises monitoring with home-based cognitive training. The primary outcome is cognition, including general functioning (Montreal Cognitive Assessment (MoCA) score), as well as executive functions, processing speed, and episodic memory (composite Z-scores based on validated neuropsychological tests and computerized tasks). The secondary outcome is physical functions, including balance (one-leg stance test), gait and mobility performance (Timed Up and Go, 4-meter walk test), leg muscle strength (5-time sit-to-stand), and estimated cardiorespiratory fitness (Matthews' questionnaire). Exploratory outcomes include mood, anxiety, and health-related quality of life as assessed by self-reported questionnaires (i.e., Geriatric depression scale-30 items, Perceived stress scale, State-trait anxiety inventory-36 items, Perseverative thinking questionnaire, Connor-Davidson Resilience Scale 10, and 12-item Short Form Survey).

DISCUSSION

This trial will document the remote monitoring of home-based physical exercise alone and home-based physical combined with cognitive training to enhance cognitive and physical health of older adults during the COVID-19 pandemic period. Remote interventions represent a promising strategy to help maintain or enhance health and cognition in seniors, and potentially an opportunity to reach older adults in remote areas, where access to such interventions is limited.

TRIAL REGISTRATION

Clinical trial Identifier NCT04635462 . COVEPIC was retrospectively registered on November 19, 2020.

Normative Data for a Tablet-Based Dual-Task Assessment in Healthy Older Adults

OBJECTIVE

The objective of this study is to provide normative data for a tablet-based dual-task assessment in older adults without cognitive deficits.

METHOD

In total, 264 participants aged between 60 and 90 years, French and English-speaking, were asked to perform two discrimination tasks, alone and concurrently. The participants had to answer as fast as possible to one or two images appearing in the center of the tablet by pressing to the corresponding buttons. Normative data are provided for reaction time (RT), coefficient of variation, and accuracy. Analyses of variance were performed by trial types (single-pure, single-mixed, dual-mixed), and linear regressions assessed the relationship between performance and sociodemographic characteristics.

RESULTS

The participants were highly educated and a large proportion of them were women (73.9%). The accuracy on the task was very high across all blocks. RT data revealed both a task-set cost and a dual-task cost between the blocks. Age was associated with slower RT and with higher coefficient of variability. Men were significantly slower on dual-mixed trials, but their coefficient of variability was lower on single-pure trials. Education was not associated with performance.

CONCLUSIONS

This study provides normative data for a tablet-based dual-task assessment in older adults without cognitive impairment, which was lacking. All participants completed the task with good accuracy in less than 15 minutes and thus, the task is transferable to clinical and research settings.

Sex-moderated association between body composition and cognition in older adults

BACKGROUND

Some studies have reported an association between body composition and cognition in older adults, but underlying mechanisms and physiological factors remain poorly understood. Moreover, sex-related differences in metabolic health and age-related cognitive decline have gained major interest lately. The present study investigated the potential moderating effect of sex on the relationship between body composition and cognition in older adults.

METHODS

Global cognition, assessed by the Montreal Cognitive Assessment (MoCA), and body composition, measured using dual-energy x-ray absorptiometry (DXA), were analyzed in 155 women and 65 men aged 60 years old or more. Moderation analyses were computed to determine if sex moderates the effect of the different body composition parameters on the MoCA while controlling for the body mass index and the level of education of the participants.

RESULTS

Sex moderated the association between total lean mass, trunk lean mass, arms lean mass, and the MoCA score. These body composition parameters were positively associated with cognition only in men. Fat mass was not associated with cognition in any sex.

CONCLUSION

Overall, higher lean mass and in particular trunk and arms lean mass was associated with higher cognitive abilities in older men. Longitudinal studies or intervention studies are needed to further identify physiological mechanisms that sustain the relationship between lean mass and cognition.

Neural Efficiency of Human-Robotic Feedback Modalities Under Stress Differs With Gender

Sensory feedback, which can be presented in different modalities - single and combined, aids task performance in human-robotic interaction (HRI). However, combining feedback modalities does not always lead to optimal performance. Indeed, it is not known how feedback modalities affect operator performance under stress. Furthermore, there is limited information on how feedback affects neural processes differently for males and females and under stress. This is a critical gap in the literature, particularly in the domain of surgical robotics, where surgeons are under challenging socio-technical environments that burden them physiologically. In the present study, we posited operator performance as the summation of task performance and neurophysiological cost of maintaining that performance. In a within-subject design, we used functional near-infrared spectroscopy to assess cerebral activations of 12 participants who underwent a 3D manipulation task within a virtual environment with concurrent feedback (visual and visual + haptic) in the presence and absence of a cognitive stressor. Cognitive stress was induced with the serial-7 subtraction test. We found that while task performance was higher with visual than visual + haptic feedback, it degraded under stress. The two feedback modalities were found to be associated with varying neural activities and neural efficiencies, and these were stress- and gender-dependent. Our findings engender further investigation into effectiveness of feedback modalities on males and females under stressful conditions in HRI.

Let's call the whole thing off: evaluating gender and sex differences in executive function

The executive functions allow for purposeful, deliberate, and intentional interactions with the world-attention and focus, impulse control, decision making, and working memory. These measures have been correlated with academic outcomes and quality of life, and are impacted by deleterious environmental events throughout the life span, including gestational and early life insults. This review will address the topic of sex differences in executive function including a discussion of differences arising in response to developmental programming. Work on gender differences in human studies and sex differences in animal research will be reviewed. Overall, we find little support for significant gender or sex differences in executive function. An important variable that factors into the interpretation of potential sex differences include differing developmental trajectories. We conclude by discussing future directions for the field and a brief discussion of biological mechanisms.

Specific transfer effects following variable priority dual-task training in older adults

PURPOSE

Past divided attention training studies in older adults have suggested that variable priority training (VPT) tends to show larger improvement than fixed priority training (FPT). However, it remains unclear whether VPT leads to larger transfer effects.

METHODS

In this study, eighty-three older adults aged between 55 and 65 received five 1-hour sessions of VPT, FPT or of an active placebo. VPT and FPT subjects trained on a complex dual-task condition with variable stimulus timings in order to promote more flexible and self-guided strategies with regard to attentional priority devoted to the concurrent tasks. Real-time individualized feedback was provided to encourage improvement. The active placebo group attended computer classes. Near and far modality transfer tasks were used to assess the generalization of transfer effects.

RESULTS

Results showed that VPT induced significantly larger transfer effects than FPT on a near modality transfer task. Evidence for larger transfer effects in VPT than FPT on a far modality transfer task was also observed. Furthermore, the superiority of VPT on FPT in transfer effects was specific to the ability to coordinate two concurrent tasks.

CONCLUSIONS

Results of this study help better understand the benefits of VPT attentional training on transfer effects, which is an essential outcome for cognitive training effectiveness and relevancy.

Ovarian hormones, sleep and cognition across the adult female lifespan: An integrated perspective

Loss of ovarian function in women is associated with sleep disturbances and cognitive decline, which suggest a key role for estrogens and/or progestins in modulating these symptoms. The effects of ovarian hormones on sleep and cognitive processes have been studied in separate research fields that seldom intersect. However, sleep has a considerable impact on cognitive function. Given the tight connections between sleep and cognition, ovarian hormones may influence selective aspects of cognition indirectly, via the modulation of sleep. In support of this hypothesis, a growing body of evidence indicates that the development of sleep disorders following menopause contributes to accelerated cognitive decline and dementia in older women. This paper draws from both the animal and human literature to present an integrated view of the effects of ovarian hormones on sleep and cognition across the adult female lifespan.

Stress and gender effects on prefrontal cortex oxygenation levels assessed during single and dual-task walking conditions

The ability to walk is critical for functional independence and wellbeing. The pre-frontal cortex (PFC) plays a key role in cognitive control of locomotion, notably under attention-demanding conditions. Factors that influence brain responses to cognitive demands of locomotion, however, are poorly understood. Herein, we evaluated the individual and combined effects of gender and perceived stress on stride velocity and PFC Oxygenated Hemoglobin (HbO₂ ) assessed during single and dual-task walking conditions. The experimental paradigm included Normal Walk (NW); Cognitive Interference (Alpha); and Walk-While-Talk (WWT) tasks. An instrumented walkway was used to assess stride velocity in NW and WWT conditions. Functional Near-Infrared-Spectroscopy (fNIRS) was used to quantify PFC HbO₂ levels during NW, Alpha and WWT. Perceived task-related stress was evaluated with a single 11-point scale item. Participants were community residing older adults (age = 76.8 ± 6.7 years; %female = 56). Results revealed that higher perceived stress was associated with greater decline in stride velocity from single to dual-task conditions among men. Three-way interactions revealed that gender moderated the effect of perceived stress on changes in HbO₂ levels comparing WWT to NW and Alpha. Attenuation in the increase in HbO₂ levels, in high compared to low perceived stress levels, from the two single task conditions to WWT was observed only in men. Thus, older men may be more vulnerable to the effect of perceived stress on the change in PFC oxygenation levels across walking conditions that vary in terms of cognitive demands. These findings confer important implications for assessment and treatment of individuals at risk of mobility impairments.