Sleep For All Ages
By Makena Wood, BSc Neuroscience
Can the time we spend not using our brains change how our brains work when we do? As it turns out, even when we are asleep, our brains are active and constantly preparing for when we will be awake. A good night’s sleep is crucial for being able to function the next day; you probably already know this from a personal experience when you didn’t get enough sleep. However, the implications for your brain may be much greater than what you glean through personal experience, and they apply across the lifespan even as your sleep patterns change. In today’s blog, I will be discussing sleep as it relates to brain function, the lesser-known restorative powers of sleep, and sleep needs and changes across the lifespan.
Benefits of sleep for the brain
Sleep is essential for learning
[Google Images]
Memory consolidation is the process of the reactivation of memories to enable their integration into long-term storage, and it is widely accepted that sleep plays a crucial part in consolidation events (Carbone et al., 2024). Therefore, one reason that sleep is important for the brain is that it helps you retain new information that you have learned so that it can be applied to new situations later on. This makes sense from an evolutionary standpoint, as learning is important to developing skills for survival.
Without enough sleep, you may not be able to successfully learn as many things or handle new situations.
Sleep restores the brain
[Google Images]
We know that sleep deprivation can lead to issues like impaired learning (as discussed above), impaired cognition (studies have shown that after 17-19 hours without sleep, cognition is at a similar or worse level to having a blood alcohol concentration of 0.05% (Williamson & Feyer, 2000)), and even serious health issues like onset of seizures (Xie et al., 2013). But, what does sleep do to prevent this all from happening? As it turns out, sleep allows for the increase in size of the interstitial space in the brain by up to 60% (Xie et al., 2013). The interstitial space is the space between blood vessels and cells where fluid circulates to help cells filter wastes. Without sleep, the interstitial space remains restricted and brain cells cannot filter and clear out metabolic wastes as efficiently. A buildup of these wastes in the central nervous system during waking hours can be toxic to the brain and detrimental to its function (Xie et al., 2013).
What does this mean for my sleep?
Sleep needs change and vary throughout the lifespan. While sleep is important for the reasons I’ve listed already, it can also serve as self-care and as a way to decrease cognitive load (read more about cognitive load in our previous blog post on “The Spoon Analogy”!). It’s important to keep your age and stage of life in mind while finding the right sleep amount and routine for yourself; this process is also sometimes referred to as sleep hygiene.
Sleep needs according to age
The American Academy of Sleep Medicine suggests the following amount of sleep by age:
Insights into age groups with trouble sleeping
Adolescents:
Telzer et al. (2015):
- Adolescence marks a period of frequent inadequate sleep accompanied by increased variability in sleep duration and sleep-wake rhythms (Colrain & Baker, 2011; Dahl & Lewin, 2002; Thorleifsdottir et al., 2002 as cited in Telzer et al., 2015).
- The increased need for sleep in childhood and adolescence as compared to adulthood, reflected in the recommendations by the American Academy of Sleep Medicine, are associated with the role of sleep in healthy brain development. Telzer et al. find that quality sleep is important for both short-term wellness and long-term development in adolescents.
- Getting adolescents into good habits for sleep (otherwise known as good sleep hygiene) may be crucial for their brain development.
Older Adults:
Scullin (2017):
- Older adults experience increased sleep disturbances, both in impeded sleep during the night and greater need for extra rest during the day (Lauderdale et al., 2014 as cited in Scullin, 2017).
- These experiences of poorer sleep appear to be somewhat of a vicious cycle. Scullin (2017) explains that poor sleep leads to cortical thinning and increased amyloid deposition. These factors are associated with cognitive decline associated with age, the pathway to Alzheimer’s disease, and decreased slow-wave sleep. This last point is where the vicious cycle comes in: poor sleep leads to a decrease in the brain’s ability to produce slow-waves for deep sleep, and a decrease in these slow waves makes it harder to achieve quality sleep at all. However, Scullin emphasizes that poor sleep is not an inevitable consequence of aging and can be managed by addressing sleep hygiene.
Sleep hygiene
[Ben Griffiths via unsplash.com]
In all cases, and across all ages, sleep quality can be improved by changes in behaviour during the day. Some simple things to consider for your personal sleep hygiene, or the sleep hygiene of someone you care for, are sleeping and waking at the same time every day, obtaining more daylight during the day and less artificial light before bed, avoiding late in the day caffeine use, and quality of diet and exercise. However, sleep hygiene in itself is a comprehensive topic that cannot be summed up by any cure-all recommendations. Stay tuned to our blog page for an upcoming post all about sleep hygiene!
In the meantime, here are some sleep hygiene resources that you may find useful:
1. sleepfoundation.org : Articles and resources for sleep education and improving personal sleep.
Here is an article about sleep hygiene: https://www.sleepfoundation.org/sleep-hygiene
2. sleepeducation.org : The American Academy of Sleep Medicine provides blog posts and tools (such as a bedtime calculator and guide to starting a sleep diary) that help educate about sleep hygiene.
References
Carbone, J., Bibian, C., Born, J., Forcato, C., & Diekelmann, S. (2024). Comparing targeted memory activation during slow wave sleep and sleep stage 2. Scientific reports, 14(1), 1-10. https://doi.org/10.1038/s41598-024-59696-y
Scullin, M.K. (2017). Do older adults need sleep? A review of neuroimaging, sleep, and aging studies. Journal of Neuroinflammation, 3(1), 204-214.
https://doi.org/10.1007/s40675-017-0086-z
Telzer, E.H., Goldenberg, D., Fuligni, A.J., Lieberman, M.D., & Galvan, A. (2015). Sleep variability in adolescence is associated with altered brain development. Developmental Cognitive Neuroscience, 14(1), 16-22. https://doi.org/10.1016/j.dcn.2015.05.007
Williamson, A., & Feyer, A. (2000). Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occupational and Environmental Medicine, 57(10), 649-655. https://doi.org/10.1136/oem.57.10.649
Xie, L., Kang, H., Xu, Q., Chen, M.J., Liao, Y., Thiyagarajan, M., O’Donnell, J., Christensen, D.J., Nicholson, C., Iliff, J.J., Takano, T., Deane, R., & Nedergaard, M. (2013). Sleep drives metabolite clearance from the adult brain. Science, 342(6156), 373-377. https://www.jstor.org/stable/42619921