Frequency of mentally stimulating activities modifies the relationship between cardiovascular reactivity and executive function in old age

Quadratic associations between cardiovascular stress reactivity and development of cool and hot executive functions in adolescents

Stress affects executive functions and exploring the association between stress-induced physiological reactivity and executive functions could highlight the potential mechanism of the stress-cognitive function link. Our study examined the linear and nonlinear associations between cardiovascular stress reactivity and cool and hot executive functions among adolescents. In November 2021 (T1), 273 Chinese adolescents between 11 and 14 (Mage = 12.93, SDage = 0.79) underwent a speech task during which their cardiovascular data were recorded, and they completed a Flanker task and an Emotional Stroop task. In May 2023 (T2), 253 adolescents again completed the Flanker and Emotional Stroop tasks. Cool and hot executive functions were assessed using the intra-individual reaction time variability of the Flanker task and Emotional Stroop task, respectively. Results showed that cardiovascular stress reactivity was positively linearly associated with cool executive functions at T1 and quadratically (inverted U-shaped) associated with cool executive functions at T1 and hot executive functions at T1 and T2. These findings suggest that compared to very high and very low cardiovascular reactivity, moderate to high cardiovascular reactivity to a structured social challenge is associated with better cool and hot executive functions.

Subjective memory in adults over 50 years of age: associations with affective and physiological markers of emotion regulation

OBJECTIVES

To examine associations among subjective memory reports, psychophysiological markers of emotion regulation, and cognitive performance in healthy adults over 50 years of age.

METHOD

A cross-sectional laboratory study was conducted with healthy, community-dwelling, non-depressed adults (M age = 60.4 years, SD = 8.4). The Metamemory in Adulthood (MIA) questionnaire provided reports of subjective memory capacity and stability (versus decline) and anxiety about memory. Poorer emotion regulation was marked by greater negative affect (NA) and lower high frequency heart rate variability (HF-HRV) responses to a challenging working memory task. Regression models were used to identify associations between subjective memory and emotion regulation markers, and structural equation modeling was used to explore whether emotion regulation mediated associations between subjective memory and objective task performance.

RESULTS

A total of 115 participants were included in the final sample. Subjective memory decline (indicated by lower scores on memory stability) was associated with lower HF-HRV response and worse working memory performance. Poorer subjective memory capacity and more anxiety about memory were both associated with greater negative affect in response to the working memory task. There was an indirect effect of subjective memory capacity on working memory performance through negative affect response.

CONCLUSIONS

The findings here suggest that worse subjective memory may signal reduced capacity for emotion regulation. Along with known cognitive risks of depression and anxiety, more subtle emotion regulation difficulties may be involved in pathways of poor cognitive aging.

Cardiovascular reactions to acute psychological stress and academic achievement

Cardiovascular reactions to acute psychological stress have been associated with cognitive function. However, previous work has assessed cardiovascular reactions and cognitive function in the laboratory at the same time. The present study examined the association between cardiovascular reactions to acute psychological stress in the laboratory and academic performance in final year high school students. Heart rate, blood pressure, stroke volume, and cardiac output reactions to an acute psychological stress task were measured in 131 participants during their final year of high school. Performance on high school A‐levels were obtained the following year. Higher heart rate and cardiac output reactivity were associated with better A‐level performance. These associations were still statistically significant after adjusting for a wide range of potentially confounding variables. The present results are consistent with a body of literature suggesting that higher heart rate reactions to acute psychological stress are associated with better cognitive performance across a variety of domains.

The present study is the first to examine the associations between cardiovascular reactions to stress in the laboratory and academic achievement. Additionally, it is the first to examine a more comprehensive hemodynamic profile of cardiovascular reactivity (e.g., cardiac output) with cognitive function. The present results are consistent with a body of literature suggesting that higher heart rate reactions to acute psychological stress are associated with better cognitive performance across a variety of domains.

Lower Cardiovascular Reactivity is Associated with More Childhood Adversity and Poorer Midlife Health: Replicated Findings from the Dunedin and MIDUS Cohorts

Cardiovascular reactivity has been proposed as a biomarker linking childhood adversity and poorer health. The current study examined the association of childhood adversity, cardiovascular reactivity, and health in the Dunedin (n=922) and MIDUS studies (n=1,015). In both studies, participants who experienced more childhood adversity had lower cardiovascular reactivity. In addition, people with lower cardiovascular reactivity had poorer self-reported health and greater inflammation. Dunedin participants with lower cardiovascular reactivity were aging biologically faster, and MIDUS participants with lower heart rate reactivity had increased risk of early mortality. Cardiovascular reactivity was not associated with hypertension in either study. Results were partially accounted for by greater reactivity among more conscientious, less depressed, and higher-functioning participants. These results suggest that people who experienced childhood adversity have a blunted physiological response, which is associated with poorer health. The findings highlight the importance of accounting for individual differences when assessing cardiovascular reactivity using cognitive stressor tasks.

Cardiovascular Stress Reactivity and Health: Recent Questions and Future Directions

OBJECTIVE

High cardiovascular reactions to psychological stress are associated with the development of hypertension, systemic atherosclerosis, and cardiovascular disease. However, it has become apparent that low biological stress reactivity also may have serious consequences for health, although less is known about the mechanisms of this. The objectives of this narrative review and opinion article are to summarize and consider where we are now in terms of the usefulness of the reactivity hypothesis and reactivity research, given that both ends of the reactivity spectrum seem to be associated with poor health, and to address some of the key criticisms and future challenges for the research area.

METHODS

This review is authored by the members of a panel discussion held at the American Psychosomatic Society meeting in 2019, which included questions such as the following: How do we measure high and low reactivity? Can high reactivity ever indicate better health? Does low or blunted reactivity simply reflect less effort on task challenges? Where does low reactivity originate from, and what is a low reactor?

RESULTS

Cardiovascular (and cortisol) stress reactivity are used as a model to demonstrate an increased understanding of the different individual pathways from stress responses to health/disease and show the challenges of how to understand and best use the reconstruction of the long-standing reactivity hypothesis given recent data.

CONCLUSIONS

This discussion elucidates the gaps in knowledge and key research issues that still remain to be addressed in this field, and that systematic reviews and meta-analyses continue to be required.

Can Reactivity of Heart Rate Variability Be a Potential Biomarker and Monitoring Tool to Promote Healthy Aging? A Systematic Review With Meta-Analyses

Background: Monitoring phasic responses of heart rate variability (HRV) in terms of HRV reactivity [i. e., the absolute change from resting state to on-task (i.e., absolute values of HRV measured during exercise)] might provide useful insights into the individual psychophysiological responses of healthy middle-aged to older adults (HOA) to cognitive and physical exercises. Objectives: To summarize the evidence of phasic HRV responses to cognitive and physical exercises, and to evaluate key moderating factors influencing these responses. Methods: A systematic review with meta-analyses was performed. Publications up to May 2020 of the databases Medline (EBSCO), Embase, Cochrane Library, CINAHL, Psycinfo, Web of Science, Scopus, and Pedro were considered. Controlled clinical trials and observational studies measuring phasic HRV responses to cognitive and/or physical exercises in HOA (≥50 years) were included. Results: The initial search identified 6,828 articles, of which 43 were included into the systematic review. Compared to resting state, vagally-mediated HRV indices were significantly reduced during all types of exercises [Hedge's g = -0.608, 95 % CI (-0.999 to -0.218), p = 0.002] indicating a significant parasympathetic withdrawal compared to rest. The key moderating variables of these responses identified included exercise intensity for physical exercises, and participant characteristics (i.e., level of cognitive functioning, physical fitness), task demands (i.e., task complexity and modality) and the individual responses to these cognitive challenges for cognitive exercises. In particular, higher task demands (task complexity and physical exercise intensity) were related to larger HRV reactivities. Better physical fitness and cognition were associated with lower HRV reactivities. Additionally, HRV reactivity appeared to be sensitive to training-induced cognitive and neural changes. Conclusion: HRV reactivity seems to be a promising biomarker for monitoring internal training load and evaluating neurobiological effects of training interventions. Further research is warranted to evaluate the potential of HRV reactivity as a monitoring parameter to guide cognitive-motor training interventions and/or as a biomarker for cognitive impairment. This may facilitate the early detection of cognitive impairment as well as allow individualized training adaptations that, in turn, support the healthy aging process by optimizing individual exercise dose and progression of cognitive-motor training.

Validity of the Polar V800 Monitor for Assessing Heart Rate Variability in Elderly Adults under Mental Stress and Dual Task Conditions

Background: Aging may result in autonomic nervous dysfunction. Heart rate variability (HRV) is a non-invasive method to measure autonomic nervous activities. Many studies have shown that HRV contributes to the risk assessment of diseases. A Polar V800 heart rate monitor is a wearable device that measures R-R intervals, but has only been validated in younger adults under limited testing conditions. There is no validation of the V800 under mental stress or in dual task testing conditions. Therefore, this study investigated the validity of the Polar V800 heart rate monitor for assessing R-R intervals and evaluated if there were differences on HRV parameters under different situations in community-dwelling elderly adults. Methods: Forty community-dwelling elderly adults were recruited. Heart rates were recorded via electrocardiogram (ECG) and the V800 under sitting, during an arithmetic test, during a naming test, a self-selected walking velocity test (SSWV), and dual tasks (SSWV performing mental arithmetic test and SSWV performing naming test). Indices of time and frequency domains of HRV were calculated afterwards. The intra-class correlation coefficient (ICC) analysis and effect size were calculated to examine the concurrent validity between the V800 and the ECG. Results: All HRV indices from the V800 were highly correlated with the ECG under all tested conditions (ICC = 0.995–1.000, p < 0.001) and the effect size of bias was small (<0.1). Conclusion: Overall, the V800 has good validity on the assessment of HRV in community-dwelling elderly adults during sitting, mental arithmetic test, naming test, SSWV, and dual tasks.

[Influences of Autonomic Function, Salivary Cortisol and Physical Activity on Cognitive Functions in Institutionalized Older Adults with Mild Cognitive Impairment: Based on Neurovisceral Integration Model]

PURPOSE

This study aimed to investigate objectively measured physical activity (PA) in institutionalized older adults with mild cognitive impairment (MCI) and to elucidate the influence of autonomic nervous function, salivary cortisol, and PA on cognitive functions based on neurovisceral integration model.

METHODS

Overall cognitive function was evaluated using the mini-mental state examination (MMSE) and executive function was evaluated using semantic verbal fluency test and clock drawing test. Actigraph for PA, HRV and sAA for autonomous function, and the geriatric depression scale for depression were used. Saliva specimens were collected in the morning for sAA and cortisol.

RESULTS

Ninety-eight older adults from four regional geriatric hospitals participated in the study. They took 4,499 steps per day on average. They spent 753.93 minutes and 23.12 minutes on average in sedentary and moderate-to-vigorous activity, respectively. In the multiple regression analysis, lower salivary cortisol level (β = - .33, p = .041) and greater step counts (β = .37, p = .029) significantly improved MMSE score. Greater step count (β = .27, p = .016) also exerted a significant influence on verbal fluency, and greater sAA (β = .35, p = .026) was significantly associated with a better clock drawing test result.

CONCLUSION

Salivary cortisol, sAA and physical activity were significantly associated with cognitive functions. To prevent older adults from developing dementia, strategies are needed to increase their overall PA amount by decreasing sedentary time and to decrease salivary cortisol for cognitive function, and to maintain their sympathetic nervous activity for executive function.

Cerebrovascular function in hypertension: Does high blood pressure make you old?

The majority of individuals over an age of 60 have hypertension. Elevated blood pressure and older age are associated with very similar changes in brain structure and function. We review the parallel brain changes associated with increasing age and blood pressure. This review focuses on joint associations of aging and elevated blood pressure with neuropsychological function, regional cerebral blood flow responses to cognitive and metabolic challenges, white matter disruptions, grey matter volume, cortical thinning, and neurovascular coupling. Treatment of hypertension ameliorates many of these changes but fails to reverse them. Treatment of hypertension itself appears more successful with better initial brain function. We show evidence that sympathetic and renal influences known to increase blood pressure also impact brain integrity. Possible central mechanisms contributing to the course of hypertension and aging are then suggested. An emphasis is placed on psychologically relevant factors: stress, cardiovascular reactions to stress, and diet/obesity. The contribution of some of these factors to biological aging remains unclear and may provide a starting point for defining the independent and interacting effects of aging and increasing blood pressure on the brain.

Good decision-making is associated with an adaptive cardiovascular response to social competitive stress

Competition elicits different psychological and cardiovascular responses depending on a person's skills. Decision-making has been considered a distal factor that influences competition, but there are no studies analyzing this relationship. Our objective was to analyze whether decision-making affects the response to competition. Specifically, we aimed to test whether good performers on a decision-making test, the Iowa Gambling Task (IGT), showed an adaptive cardiovascular response to competition. In all, 116 participants (44 women) performed the IGT and were classified into Good or Poor decision-makers. Subsequently, they were exposed to a stress task in two different conditions: a face-to-face competition (winners/losers) or a control condition, while an electrocardiogram was recorded. In the competition group, good decision-makers increased their high-frequency respect to the total heart rate variability (HF/HRV) levels during the task, compared to Poor decision-makers. Again, competition group good decision-makers, showed lower LF and higher HF/HRV reactivity than the control group, which represents lower HRV stress pattern. Moreover, in the group of losers, good decision-makers had a decline in low frequency (LF) during the task and faster recovery than poor decision-makers. In conclusion, good decision-makers have a more adaptive stress response and higher levels of mental effort, based on total HRV interpretation. Decision-making skills could be a factor in a more adaptive cardiovascular response to competition.

The Influence of Environmental Enrichment on Cardiovascular and Behavioral Responses to Social Stress

OBJECTIVE

Stress is linked to negative cardiovascular consequences and increases in depressive behaviors. Environmental enrichment (EE) involves exposure to novel items that provide physical and cognitive stimulation. EE has behavioral, cognitive, and neurobiological effects that may improve stress responses in humans and animal models. This study investigated the potential protective effects of EE on behavior and cardiovascular function in female prairie voles after a social stressor.

METHODS

Radiotelemetry transmitters were implanted into female prairie voles to measure heart rate (HR) and heart rate variability (HRV) throughout the study. All females were paired with a male partner for 5 days, followed by separation from their partner for 5 additional days, and a 10-day treatment period. Treatment consisted of continued isolation, isolation with EE, or re-pairing with the partner (n = 9 per group). After treatment, animals were observed in the forced swim test (FST) for measures of stress coping behaviors.

RESULTS

Isolation elevated HR and reduced HRV relative to baseline for all groups (p < .001). HR and HRV returned to baseline in the EE and re-paired groups, but not in the continued isolation group (p < .001). Animals in the EE and re-paired groups displayed significantly lower immobility time (p < .001) and HR (p < .03) during the FST, with a shorter latency for HR to return to baseline levels after the FST, relative to the continued isolation group (p < .001).

CONCLUSIONS

EE and re-pairing reversed the negative behavioral and cardiovascular consequences associated with social isolation.

Cortical thickness is associated with altered autonomic function in cognitively impaired and non-impaired older adults

KEY POINTS

The parasympathetic nervous system (PNS) is critical for adaptation to environment demands. Alzheimer's disease (AD), via frontal compensatory processes, may affect PNS regulation, thereby compromising older adults' capacity for adaptation, and increasing morbidity and mortality risk. Here we found that AD-associated neurodegeneration accompanied an overactive anterior cingulate cortex, which in turn resulted in a high level of PNS activity at rest, as well as strong PNS activity withdrawal in response to the mental effort. This discovery provides the first line of evidence to suggest that AD-associated neurodegeneration links to altered PNS regulation during mental effort in older adults, and that the compensatory processes accompanying frontal hyperactivation appear to be responsible for these alterations.

ABSTRACT

The parasympathetic nervous system (PNS) is critical for adaptation to environment demands. PNS can reflect an individual's regulatory capacity of frontal brain regions and has been linked to cognitive capacity. Yet, the relationship of PNS function to cognitive decline and abnormal frontal function that characterize preclinical progression toward Alzheimer's disease (AD) is unclear. Here, we aimed to elucidate the relationship between PNS function and AD-associated neurodegeneration by testing two competing hypotheses involving frontal regions' activity (neurodegeneration vs. compensation). In 38 older human adults with amnestic mild cognitive impairment (aMCI) or normative cognition, we measured AD-associated neurodegeneration (AD signature cortical thickness; ADSCT), resting-state functional magnetic resonance imaging of frontal regions' spontaneous activation, and an electrocardiography measure of PNS (high frequency heart rate variability; HF-HRV). HF-HRV was assessed at rest and during a cognitive task protocol designed to capture HF-HRV reactivity. Higher HF-HRV at rest was significantly related to both more severe AD-associated neurodegeneration (lower ADSCT scores) and worse cognitive ability. Cognitive impairments were also related to greater suppression of HF-HRV reactivity. High activities of the anterior cingulate cortex significantly mediated relationships between ADSCT and both HF-HRV at rest and HF-HRV reactivity. Notably, these relationships were not affected by the clinical phenotype. We show that AD-associated neurodegeneration is associated with altered PNS regulation and that compensatory processes linked to frontal overactivation might be responsible for those alterations. This finding provides the first line of evidence in a new framework for understanding how early-stage AD-associated neurodegeneration affects autonomic regulation.

Predictors of aging based on the analysis of heart rate variability

BACKGROUND

The current significant progress in the use of heart rate variability in the solution of many diagnostic and therapeutic problems is determined by the availability of standardized methods of measurement and physiological interpretation of heart rate variability indices on the one hand and the high technological level of state-of-the-art electronic measuring equipment that is used for automatic registration and computer processing of cardio-signals.

METHODS

A retrospective analysis of anonymized cardio screening results of 22,433 adult residents of 565 settlements (cities and villages) across all 20 administrative districts of the Khmelnytskyi Region (Ukraine) was conducted to find a statistically significant connection between individual heart rate variability parameters and the age of people.

RESULTS

Primary statistical analysis and visualization showed a correlation between the selected heart rate variability parameters and the age and sex of the examined persons. The study found values of the predicted age slightly over estimation versus the actual age for very young test subjects and below estimation for elderly subjects.

CONCLUSION

The use of neural network computations and the modification of the algorithm through the construction of individual training samples for different age intervals, and the creation of individual ensembles of classification neural networks, therefore achieved a prediction of the age of examined persons based on the values of their time and frequency domain heart rate variability indices, with 87% accuracy for women and 85% accuracy for men in the 66-85 years age interval and at least 85% for age groups across the entire sample.

Activity engagement and physical function in old age sample

OBJECTIVES

To describe the patterns of engagement in mental, physical, and social activity (MA, PA, and SA) and to examine the relationship between combined activity engagement and physical function among community-dwelling older adults.

DESIGN

Cross-sectional correlational study.

SETTING

Multiple communities.

PARTICIPANTS

A total of 466 individuals aged 55 years or older.

MEASUREMENTS

Physical function was assessed using grip strength and gait speed. Engagement in PA, MA and SA was obtained from self-report questionnaires.

RESULTS

We identified four classes ("Active PA and MA", "Active MA", "Active PA", and "Inactive") that significantly differed in the frequency of engagement in MA and PA using latent class analysis. SA didn't differ across classes. Controlling for age, the "Active PA and MA", "Active MA", "Active PA" groups displayed similar grip strength that was superior to the "Inactive" group. "Active PA and MA" group had best gait speed relative to other groups, especially "Active MA" and "Inactive" group, while the "Active PA", "Active MA", and "Inactive" group were similar in gait speed.

CONCLUSION

Combined physical and mental activity engagement was associated with better physical function, especially in gait speed. Future interventional research should investigate the combination of both physical and cognitive training to prevent decline of physical function in older adults.

Mental Fatigability and Heart Rate Variability in Mild Cognitive Impairment

OBJECTIVES

Adaptive physiological stress regulation is rarely studied in mild cognitive impairment (MCI). Here we targeted mental fatigability (MF) as a determinant of altered high frequency heart rate variability (HF-HRV) reactivity in individuals with MCI, and examined frontobasal ganglia circuitry as a neural basis supporting the link between MF and HF-HRV reactivity.

METHODS

We measured mental fatigability and HF-HRV during a 60-minute cognitive stress protocol in 19 individuals with MCI. HF-HRV responses were modeled using a quadratic equation. Resting state functional connectivity of intra- and inter-network frontobasal ganglia circuitry was assessed using blood-oxygen-level-dependent magnetic resonance imaging among seven of the participants.

RESULTS

Lower MF was associated with faster and greater rebound in U-shape HF-HRV reactivity, which linked to a stronger connectivity between right middle frontal gyrus and left putamen.

CONCLUSIONS

Results suggest that MF may contribute to abnormal physiological stress regulation in MCI, and fronto basal ganglia circuitry may support the link.

Stress Regulation as a Link between Executive Function and Pre-Frailty in Older Adults

OBJECTIVES

Both pre-frailty and frailty are linked with impaired executive function (EF) but the mechanism underlying this relationship is not known. Williams and colleagues' model posits EF affects health outcomes via stress regulation. This model was utlized to test indicators of stress regulation as mediators of the relationship between EF and pre-frailty in older adults.

DESIGN

Cross-sectional.

SETTING

Academic general clinical research centers.

PARTICIPANTS

690 community-dwelling older adults ≥ 50 years of age.

MEASUREMENTS

Pre-frailty was measured using a modified form of the Fried Frailty measure. EF was assessed via telephone-based neurocognitive assessments. Indicators of stress regulation included: stress exposure (measured by perceived stress), reactivity and recovery (measured by heart rate) and restoration (measured by serum interleukin-6 and sleep quality).

RESULTS

396 individuals were classified as non-frail, 277 as pre-frail, and 17 as frail. Pre-frail and non-frail individuals were included in data analyses. Compared to non-frail individuals, pre-frail were older and exhibited poorer EF, higher levels of stress exposure and poorer stress restoration. Poorer EF was associated with greater stress exposure, less stress reactivity, longer stress recovery and poorer stress restoration. The total effect of the relationship between EF and pre-frailty was significant with significant indirect effects supporting stress exposure and restoration as mediators of the relationship.

CONCLUSION

Stress exposure and restoration appear to mediate the relationship between EF and pre-frailty. Longitudinal studies are needed to clarify the direction of causality and determine whether stress regulation processes are appropriate targets for interventions aiming to prevent declines in EF and the development of pre-frailty.

Age differences in high frequency phasic heart rate variability and performance response to increased executive function load in three executive function tasks

The current study examines similarity or disparity of a frontally mediated physiological response of mental effort among multiple executive functioning tasks between children and adults. Task performance and phasic heart rate variability (HRV) were recorded in children (6 to 10 years old) and adults in an examination of age differences in executive functioning skills during periods of increased demand. Executive load levels were varied by increasing the difficulty levels of three executive functioning tasks: inhibition (IN), working memory (WM), and planning/problem solving (PL). Behavioral performance decreased in all tasks with increased executive demand in both children and adults. Adults' phasic high frequency HRV was suppressed during the management of increased IN and WM load. Children's phasic HRV was suppressed during the management of moderate WM load. HRV was not suppressed during either children's or adults' increasing load during the PL task. High frequency phasic HRV may be most sensitive to executive function tasks that have a time-response pressure, and simply requiring performance on a self-paced task requiring frontal lobe activation may not be enough to generate HRV responsitivity to increasing demand.

The Moderating Effect of Personality Type on the Relationship between Leisure Activity and Executive Control in Older Adults

We examined the moderating effect of personality on the association between leisure activities and executive control in healthy community-dwelling older adults. We found two distinct personality typologies: individuals with a Resilient personality were characterized by emotional stability and self-confidence; whereas, those who resembled an Overcontrolled personality tended to be introverted, but also low on neuroticism. Resilient individuals were more likely than Overcontrolled individuals to demonstrate higher executive function and attention as a result of participation in mental activities. These results suggest that personality might be important to include in studies that test the efficacy of activity interventions for improving cognition.

Evaluation of objective and perceived mental fatigability in older adults with vascular risk

OBJECTIVES

Mental fatigability refers to the failure to sustain participation in tasks requiring mental effort. Older adults with vascular risk are at particular risk for experiencing mental fatigability. The present study (1) tested a new way of measuring objective mental fatigability by examining its association with perceived mental fatigability; and (2) identified associated psychological, physiological, and situational predictors.

METHODS

A cross-sectional study was conducted with 49 community-dwelling participants aged 75+ years with vascular risk. A 20-minute fatigability-manipulation task was used to induce mental fatigability and develop objective and perceived mental fatigability measures. Objective fatigability was calculated by the change of reaction time over the course of the task. Perceived fatigability was calculated by the change of fatigue self-reported before and after the task. A set of potential psychological, physiological, and situational predictors were measured.

RESULTS

There was a significant increase in reaction time and self-reported fatigue to the fatigability manipulation task, indicating occurrence of objective and perceived mental fatigability. Reaction time and self-reported fatigue were moderately, but significantly correlated. Higher levels of executive control and having a history of more frequently engaging in mental activities were associated with lower objective mental fatigability. None of the examined factors were associated with perceived mental fatigability.

CONCLUSION

Objective and perceived mental fatigability were sensitive to our fatigability-manipulation task. While these two measures were correlated, they were not associated with the same factors. These findings need to be validated in studies with a more heterogeneous sample and a greater variety of fatigability-manipulation tasks.