Written by Josh Horsman
We all know that getting enough sleep is important. When we are tired, we don’t feel like ourselves, right? But have you ever thought about why it is that you feel that way? The answer lies in the fascinating relationship between sleep and the brain. The two are inextricably linked with the latter relying on the former for performing its key functions, maintaining its overall health.
Simply put, your brain cannot function effectively without good-quality sleep and, in its absence, the impact of sleep deprivation is felt across all key areas of cognitive function, including: Memory, concentration, alertness and mood. Sleep deprivation can also be linked to the onset of a number of serious cognitive conditions such as Dementia! The effect of sleep deprivation on each of these areas of cognitive function is also supported by a strong and growing body of scientific research.
Let's explore the effects of tiredness on the key areas of cognitive function:
When we don’t get sufficient, good-quality sleep, memory is affected because the brain uses the hours of shuteye to filter, sort and consolidate information and create memories. This means that when we aren’t sleeping enough, we are not just forgetting things more easily, but memories aren’t able to form in the first place, and you will have difficulty recalling information that is stored.
Research has shown this to be true. One study at Harvard Medical School, for example, involved participants who had to learn a routine of tapping buttons in a certain order. They were asked to learn the task and then recall it. Those who were given a night of sleep between learning and recalling significantly outperformed those who spent the intermittent period awake. This adds significant weight behind the idea that sleep facilitates both the brain’s ability to store and recall information.
The brain’s capacity to react to situations is also significantly compromised by a lack of sleep. Both judgement and speed of reaction as well as coordination have been proven to suffer under sleep deprivation. In fact, just 19 hours without sleep is enough to reduce your brain’s ability to react to levels similar to those if you were legally drunk!
When we go without sleep, our brain’s ability to focus on specific tasks is compromised and this results in our feeling like we are unable to concentrate. Your brain will be less able to handle multi-tasking or to take in and process information. This is why we are advised not to drive when we are tired, for example. Not being able to focus on the task in-hand in turn impairs our creativity and decision-making.
Your mood and mental health are also considerably affected by sleep deprivation. The down-time during sleep enables your brain to regulate your mood and helps with the balance of chemicals within it. When you have not slept enough you’re far more prone to irritability, and feeling cranky and unlike yourself. Stress can also be emphasized when you are tired.
Even more worrying is the growing body of clinical research from recent years which suggests that being regularly deprived of sleep could leave the brain more susceptible to the onset of Alzheimer’s Disease and other forms of Dementia.
This seems to be because the brain uses sleep to cleanse itself of harmful substances. Studies show that during sleep the spaces between brain cells expand significantly and this allows the expulsion of toxins through cerebrospinal fluid. Among the toxins, which accumulate during the day and are then cleared during sleep, is β-amyloid, a protein which is a precursor to Alzheimer’s. This supports other research which lists regular good-quality sleep as an important lifestyle factor for preventing Dementia.
Ultimately, regular disrupted sleep is likely to translate into reduced cognitive performance in daily life and could be damaging to brain health in the long term. Of course sleep doesn't come easy for everyone and finding a regular pattern can be complicated by many aspects of life. If you are having trouble getting consistent, good-quality sleep then check out this article for some great ideas to help you get regular rest.