Executive Functions And The Aging Brain
Written by Cameron Anderson, BSc Neuroscience,
Executive functions allow an individual to successfully concentrate, plan, and take action to achieve their goals (Abd-alrazaq et al., 2022). Three of these executive functions are: working memory, inhibitory control, and cognitive flexibility. Working memory references an individual’s ability to maintain and manipulate information in their current awareness (Vartanian et al., 2022). Inhibitory control is needed to resist interferences that may intrude on working memory. These interferences may be external distractions, or learned responses that may not be appropriate for the situation. (Godwin et al., 2023). Cognitive flexibility refers to the ability to quickly shift attention and focus. Cognitive flexibility also plays a part in how we alter response strategies, allowing us to flexibly adjust to new demands, rules, or priorities. Individuals with high cognitive flexibility are able to think outside the box, and adapt their perspectives (Mou et al., 2023).
Hindered executive functions arise from an imbalance of these three categories. As a result, individuals with poor executive functions may struggle in the processes of focusing, planning, or acting (Karr et al., 2022). Poor executive function performance predicts maladaptive coping styles. Maladaptive coping styles may result in the source of stress not being dealt with appropriately. This could lead to increases in stress levels and length. Conversely, strong executive function capabilities are predictive of approach-based stress coping styles. These styles allow individuals to deal with objects of stress effectively. In this way, stressors are more manageable, and have fewer negative effects. (Nieto et al., 2020). Statistically, older adults with stronger executive function capabilities report a higher quality of life (Laera et al., 2023).
Executive function development follows an upside-down ‘U’ shaped curve, building in infancy, reaching a maximum, and then declining later in life. This is a natural aging process, but steps can be taken to ensure a strengthening or upkeep of executive function capabilities. Strengthening of executive functions can be achieved through a multitude of pathways: exercise, sleep, nutrition, play, and interpersonal relationships all play a significant role in keeping the brain healthy, and executive functions in optimal conditions. Sleep, nutrition, and play alongside interpersonal relations, have been examined in previous blog posts, looking at how they can help strengthen the aging brain.
Exercise is another common thread that appears when looking at how to keep the brain healthy, and executive functions in top condition. The positive effects of physical exercise on the brain and executive functions have been noted in many studies (Abd-alrazaq et al., 2022; Chainay et al., 2021; Chu et al., 2023; Mou et al., 2023; Xiong et al., 2021). A session of exercise commonly used in these studies and others, is engaging in a minimum of a 30-minute period of walking, or equivalent aerobic activity. In a 2021 study by Chainay et al, how physical exercise would affect working memory tasks in older adults was examined. Older adults underwent two 1-hour walking sessions per week for 8 weeks. At the cognitive testing period at the end of the 8-week period, participants who exercised performed better on working memory tasks. It is interesting to note improvements seen in the walking group were similar to results seen in a mixed group, who did both physical and cognitive training. (Chainay et al., 2021). A 2023 study by Chu et al, examined the effects of exercise on older adults and their inhibitory control. It was observed that after undergoing a moderate-intensity exercise, greater accuracy was observed in participants undergoing an inhibitory control task. It is interesting to note that the greatest beneficial effects on inhibitory control tasks were seen after moderate exercise, as compared to low or high intensity exercise. (Chu et al., 2023). In a meta-analysis by Xiong et al, a large number of studies examining the impact of physical exercise and improvements in executive functions in older adults were analyzed. Improvements in tasks that measured cognitive flexibility were seen in a wide variety of activities, such as: walking, cycling, resistance training, seated and standing aerobic exercises, tai chi, and yoga, among others. Many of these exercises ranged from 30-60 minutes of physical activity, 2 to 3 times a week. As well, improvements in working memory and inhibitory control were seen in many of these activities as well. (Xiong et al., 2021).
Although executive functions decline naturally as part of the aging process, steps can be taken to prevent their decline, and even strengthen these skills. Exercise is associated with increases in working memory, inhibitory control, and cognitive flexibility in older adults. Exercise is only one way to help strengthen the brain and its execution functions. Sleep, nutrition, play, and interpersonal relationships have all produced observable benefits on executive functions and overall brain health, as noted in previous posts.
References
Abd-alrazaq, A., Alhuwail, D., Ahmed, A., & Househ, M. (2022.) Effectiveness of Serious Games for Improving Executive Functions Among Older Adults With Cognitive Impairment: Systematic Review and Meta-analysis. JMIR Serious Games, 10(3): e36123. Doi: https://doi.org/10.2196/36123
Chainay, H., Joubert, C., & Massol, S. (2021.) Behavioural and ERP effects of Cognitive and Combined Cognitive and Physical Training on Working Memory and Executive Function in Healthy Older Adults. Advances in Cognitive Psychology, 17(1), 58-69. https://doi.org/10.5709/acp-0317-y
Chu, C., Kao, S., Hillman, C.H., Chen, F., Li, R., Ai, J., & Chang, Y. (2023). The influence of volume-matched acute aerobic exercise on inhibitory control in late-middle-aged and older adults: A neuroelectric study. Psychophysiology, 60(12):e14393. https://doi.org/10.1111/psyp.14393
Godwin, K.E., Thompson, C.A., Kaur, F., Iwai, Y., Fitzsimmons, C.J., & Taber, J.M. (2023.) Attending to what’s important: what heat maps may reveal about attention, inhibitory control, and fraction arithmetic performance. Frontiers in Psychology, 14:1210266. https://doi.org/10.3389/fpsyg.2023.1210266
Karr, J.E., Rodriguez, J.E., Goh, P.K., Matrel, M.M., & Rast, P. (2022.) The Unity and Diversity of Executive Functions: A Network Approach to Life Span Development. Developmental Psychology, 58(4), 751-767. https://doi.org/10.1037/dev0001313
Laera, G., Joly-Burra, E., Zuber, S., Ballhausen, N., Künzi, M., Ihle, A., Da Silva Coelho, C., Haas, M., Mikneviciute, G., Tinello, D., Kliegel, M., & Hering, A. (2023.) Do executive functions explain older adults’ health-related quality of life beyond event-based prospective memory? Aging, Neuropsychology, and Cognition, 30(2), 135-149. https://doi.org/10.1080/13825585.2021.1989368
Mou, H., Tian, S., Yuan, Y., Sun, D., & Qiu, F. (2023.) Effect of acute exercise on cognitive flexibility: Role of baseline cognitive performance. Mental Health and Physical Activity, 25:100522. https://doi.org/10.1016/j.mhpa.2023.100522
Nieto, M., Romero, D., Ros, L., Zabala, C., Martínez, M., Ricarte, J.J., Serrano, J.P., & Latorre, J.M. (2020.) Differences in Coping Strategies Between Young and Older Adults: The Role of Executive Functions. The International Journal of Aging and Human Development, 90(1), 28-49. DOI: https://doi.org/10.1177/0091415018822040
Stenbäck, V., Marsja, E., Hällgren, M., Lyxell, B., & Larsby, B. (2021.) The Contribution of Age, Working Memory Capacity, and Inhibitory Control on Speech Recognition in Noise in Young and Older Adult Listeners. Journal of Speech, Language, and Hearing, 64(11), 4513-4523. https://doi.org/10.1044/2021_JSLHR-20-00251
Vartanian, O., Replete, V., Saint, S.A., Lam, Q., Forbes, S., Beaudoin, M.E., Brunyé, T.T., Bryant, D.J., Feltman, K.A., Heaton, K.J., McKinley, R.A., Van Erp, J.B.F., Vergin, A., & Whittaker, A. (2022.) What Is Targeted When We Train Working Memory? Evidence From a Meta-Analysis of the Neural Correlates of Working Memory Training Using Activation Likelihood Estimation. Frontiers in Psychology, 13:868001. https://doi.org/10.3389/fpsyg.2022.868001
Xiong, J., Mingzhu Y., Wang., L., & Guohua, Z. (2021.) Effects of physical exercise one executive function in cognitively healthly older adults: A systematic review and meta analysis of randomized controlled trials. International Journal of Nursing Studies, 114:103810.https://doi.org/10.1016/j.ijnurstu.2020.103810