How Sleep Affects The Mind
In the previous segment of this series, I discussed the importance of sleep and how the body is impacted by sleep deprivation. As it turns out, there’s a ton of impact, both short-term and long-term! But that’s not the end of the conversation. Sleep has a profound effect on our psychology along with our physicality.
Think of the last time you had a terrible night of sleep. You probably felt tired, unmotivated, maybe even sick. But is the effect of a bad night’s sleep only physical? If you’re anything like me, the answer to that question is no. Not only is the body affected by sleep deprivation, but so is the mind.
The mind and the body’s alarm system
In my previous article, I looked at the fight or flight system (the body’s protective strategy when it senses a threat). This system also engages the mind! If you think back to the last time you were in danger and your internal “alarm system” went off, how did you feel? What was going through your head?
In the same moment that your heart pounds, palms sweat, and muscles tense, a host of reactions occur in your mind too. Emotions ramp up and you can feel the anxiety and fear building in your chest. Your mind races as it struggles to decide on a course of action to respond to the threat. Or, it goes completely blank. You feel overwhelmed and stressed; any little thing could put you over the edge.
This range of responses illustrates how the mind responds to a lack of sleep. It is not functioning normally; you’re either over-activated or under-activated. Just like the body, the mind gears up to defend against the threat of sleep loss.
Sleep’s effect on concentration, memory, and emotion
Of all the ways that sleep loss impacts the mind, its effect on concentration is one of the most noticeable and consequential (Williams, 2017; Walker, 2017). Staying focused on a simple task becomes increasingly difficult after a night of poor sleep. Sustaining attention is not only made difficult by slowed reaction time but by what researchers have coined “microsleep”: actually falling asleep for a few seconds without realizing it and missing key moments of life (Walker, 2017).
Microsleep explains further why concentration is affected by sleep deprivation—your mind keeps slipping into microsleep and disrupting your attempts to focus on a task. Sleep’s impact on concentration makes driving while drowsy so dangerous; it is comparable to driving under the influence. Imagine how long it takes for a car crash to happen. What could happen in those few seconds when a person slips into microsleep while behind the wheel?
Another significant area of disruption is memory encoding. While this is a relatively new area of research, studies are beginning to show the connection between a good night's sleep and the ability to store information in memory. In essence, when you get a poor night’s sleep, the process of encoding memory is disrupted (Gazzaniga et al., 2016). If you get a good night's sleep, you give your brain a chance to consolidate the information gained during the day.
Furthermore, sleep deprivation has a way of amplifying our emotions and lowering our ability to manage stress. This is in part because, with a lack of sleep, our perception becomes skewed and we can be more easily overwhelmed by normally manageable events. Later on, when the sleep-deprived brain works to consolidate those memories, the intensified emotional data throws off the whole process. The combined effect of sleep deprivation on concentration, emotion, stress management, and memory creates another snowball effect.
All of these elements end up having a cumulative effect on the mind and one’s mental health. For those who have been diagnosed with a mental illness, consistently poor sleep can lead to worsening symptoms. To put it another way, sleep hygiene (getting regular, consistent, restful sleep) can work wonders on mental health!
Hope for better sleep hygiene
Once again, there is hope! Many of the problems highlighted in each of these articles can be remedied by simply getting a good night’s sleep. Unfortunately, modern society is not always cooperative with that goal. It can be a challenge for many people to get the sleep they need. That’s why it’s important to be informed on the topic. As we continue into the third and final part of this series, I will look at “sleep hygiene” and provide a guide to improve it.
Gazzaniga, M., Heatherton, T., & Halpern, D. (2016). Psychological Science, 5th ed. New York: W.W. Norton
Walker, M. (2017). Why We Sleep. Scribner.
Williams, L. (2017). Sleep Deprivation: Global Prevalence, Dangers and Impacts on Cognitive Performance. Nova Science Publishers, Inc.