Browsing by Subject "Executive functions"

Now showing 1 - 4 of 4
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    Benefits of Higher Cardiovascular and Motor Coordinative Fitness on Driving Behavior Are Mediated by Cognitive Functioning: A Path Analysis
    (Frontiers Media, 2021-06-29) Stojan, Robert; Kaushal, Navin; Bock, Otmar Leo; Hudl, Nicole; Voelcker-Rehage, Claudia; Health Sciences, School of Health and Human Sciences
    Driving is an important skill for older adults to maintain an independent lifestyle, and to preserve the quality of life. However, the ability to drive safely in older adults can be compromised by age-related cognitive decline. Performing an additional task during driving (e.g., adjusting the radio) increases cognitive demands and thus might additionally impair driving performance. Cognitive functioning has been shown to be positively related to physical activity/fitness such as cardiovascular and motor coordinative fitness. As such, a higher fitness level might be associated with higher cognitive resources and may therefore benefit driving performance under dual-task conditions. For the first time, the present study investigated whether this association of physical fitness and cognitive functioning causes an indirect relationship between physical fitness and dual-task driving performance through cognitive functions. Data from 120 healthy older adults (age: 69.56 ± 3.62, 53 female) were analyzed. Participants completed tests on cardiovascular fitness (cardiorespiratory capacity), motor coordinative fitness (composite score: static balance, psychomotor speed, bimanual dexterity), and cognitive functions (updating, inhibition, shifting, cognitive processing speed). Further, they performed a virtual car driving scenario where they additionally engaged in cognitively demanding tasks that were modeled after typical real-life activities during driving (typing or reasoning). Structural equation modeling (path analysis) was used to investigate whether cardiovascular and motor coordinative fitness were indirectly associated with lane keeping (i.e., variability in lateral position) and speed control (i.e., average velocity) while dual-task driving via cognitive functions. Both cardiovascular and motor coordinative fitness demonstrated the hypothesized indirect effects on dual-task driving. Motor coordinative fitness showed a significant indirect effect on lane keeping, while cardiovascular fitness demonstrated a trend-level indirect effect on speed control. Moreover, both fitness domains were positively related to different cognitive functions (processing speed and/or updating), and cognitive functions (updating or inhibition), in turn, were related to dual-task driving. These findings indicate that cognitive benefits associated with higher fitness may facilitate driving performance. Given that driving with lower cognitive capacity can result in serious consequences, this study emphasizes the importance for older adults to engage in a physically active lifestyle as it might serve as a preventive measure for driving safety.
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    Physical Exercise Training Effect and Mediation Through Cardiorespiratory Fitness on Dual-Task Performances Differ in Younger–Old and Older–Old Adults
    (Oxford University Press, 2021) Bherer, Louis; Langeard, Antoine; Kaushal, Navin; Vrinceanu, Tudor; Desjardins-Crépeau, Laurence; Langlois, Francis; Kramer, Arthur F.; Health Sciences, School of Health and Human Sciences
    Objective: It has often been reported that dual-task (DT) performance declines with age. Physical exercise can help improve cognition, but these improvements could depend on cognitive functions and age groups. Moreover, the mechanisms supporting this enhancement are not fully elucidated. This study investigated the impacts of physical exercise on single- and dual-task performance in younger-old (<70) and older-old (70+) adults. The study also assessed whether the training effect on cognition was mediated by improvement in cardiorespiratory fitness. Methods: One hundred forty-three participants (65-89 years) took part in a physical exercise intervention for 3 months or were assigned to a control group. All participants completed a DT paradigm and an estimated measure of cardiorespiratory fitness. Regression models were used to test the training effect on these outcomes, and mediation analyses were used to determine whether the training-related cognitive changes were mediated by changes in cardiorespiratory fitness. Results: In 70+, training predicted improved processing speed (βc = -.33) and cardiorespiratory fitness (βa = .26) and the effect of training on processing speed was fully mediated by change in cardiorespiratory fitness (βab = -.12). In <70, training predicted improvement in task-set cost (βc = -.26) and change in cardiorespiratory fitness (βa = .30) but improvement in task-set cost was not entirely mediated by change in cardiorespiratory fitness. Discussion: Results are discussed in terms of the mechanisms supporting DT performance improvement following physical exercise training in older adults.
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    Psilocybin targets a common molecular mechanism for cognitive impairment and increased craving in alcoholism
    (American Association for the Advancement of Science, 2021) Meinhardt, Marcus W.; Pfarr, Simone; Fouquet, Grégory; Rohleder, Cathrin; Meinhardt, Manuela L.; Barroso-Flores, Janet; Hoffmann, Rebecca; Jeanblanc, Jérôme; Paul, Elisabeth; Wagner, Konstantin; Hansson, Anita C.; Köhr, Georg; Meier, Nils; von Bohlen und Halbach, Oliver; Bell, Richard L.; Endepols, Heike; Neumaier, Bernd; Schönig, Kai; Bartsch, Dusan; Naassila, Mickaël; Spanagel, Rainer; Sommer, Wolfgang H.; Psychiatry, School of Medicine
    Alcohol-dependent patients commonly show impairments in executive functions that facilitate craving and can lead to relapse. However, the molecular mechanisms leading to executive dysfunction in alcoholism are poorly understood, and new effective pharmacological treatments are desired. Here, using a bidirectional neuromodulation approach, we demonstrate a causal link between reduced prefrontal mGluR2 function and both impaired executive control and alcohol craving. A neuron-specific prefrontal mGluR2 knockdown in rats generated a phenotype of reduced cognitive flexibility and excessive alcohol seeking. Conversely, virally restoring prefrontal mGluR2 levels in alcohol-dependent rats rescued these pathological behaviors. In the search for a pharmacological intervention with high translational potential, psilocybin was capable of restoring mGluR2 expression and reducing relapse behavior. Last, we propose a FDG-PET biomarker strategy to identify mGluR2 treatment-responsive individuals. In conclusion, we identified a common molecular pathological mechanism for both executive dysfunction and alcohol craving and provided a personalized mGluR2 mechanism-based intervention strategy for medication development for alcoholism.
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    Stability of Subjective Executive Functioning in Older Adults with aMCI and Subjective Cognitive Decline
    (Oxford University Press, 2021) Carmasin, Jeremy S.; Roth, Robert M.; Rabin, Laura A.; Englert, Jessica J.; Flashman, Laura A.; Saykin, Andrew J.; Radiology and Imaging Sciences, School of Medicine
    Objective: Subjective memory concerns are characteristic of individuals with amnestic mild cognitive impairment (aMCI) and subjective cognitive decline (SCD), though subjective changes in executive functions have also been reported. In a cohort study, we examined the temporal stability of subjective report of executive functioning in a high education (mean = 16.8 years) sample of cognitively normal (CN) older adults and those with aMCI or SCD. Method: Participants (CN, n = 22; aMCI, n = 21; SCD, n = 24) and their informants completed the BRIEF-A and neuropsychological tests at two time points separated by approximately 1 year. Results: Analyses focused on those with diagnostic stability (95.7%). Participants with aMCI and SCD, and their informants, endorsed worse executive functions relative to CN at both time points. No group by time interaction was observed for subjective or objective measures of executive function. Conclusions: Diagnostically stable CN older adults, and those with prodromal dementia conditions, report stable executive functioning at 1-year follow-up.