Cognition and Sleep Quality Connection
Mental health and cognition are two key benefits of quality sleep. Researchers continue to learn about the importance of sleep for cognition and mental health. Quality sleep can improve thought processes, mood, and efficiency. Poor sleep, however, can affect the ability to think clearly, focus, and even regulate emotions. There are things you can do to improve your sleep to make the most of your mental capacity.
Major factors in falling asleep include relaxation and timing. These can be derailed by cognitive activity. Mental activity (such as attention, concentration, information processing, and recall of information) can arouse the brain and delay the onset of sleep. Fortunately, sleep specialists can turn this around by retraining the brain to relax—to literally “turn the brain off.” This allows other brain structures to activate sleep. If mental activity causes a severe problem, including hours of wakefulness nightly for weeks, in falling asleep, relaxation techniques and/or medication may help.
Sleep is Important to Cognition
Researchers are particularly interested in how frequent, poor sleep negatively affects cognitive abilities. A night of sleep is composed of phases of light sleep, deep sleep, and dream sleep which repeat three or four times each night. The interruption or shortening of these phases can impact daytime cognitive functioning. Poor sleep quality compromises one’s ability to pay attention, concentrate, plan, remember details, and monitor thinking.
There are several studies that ask healthy participants to limit their sleep by restricting the amount of sleep, and/or purposely waking them up. The findings revealed that this “poor sleep” results in the dulling of attention and cognitive abilities. Differences in high order “executive” thinking activities occurred when sleep was reduced by just 10% or less than seven hours. Executive level activities include creative thinking, generating new ideas, or figuring out how to solve a puzzle.
Effects of Poor Sleep on Cognition
Low cognition levels can lead to fogginess, forgetfulness, and generally operating at less-than-optimal levels. These factors can impact sleep quality and daytime mood. The physical and mental fatigue from poor sleep and low cognitive levels appear to make mood issues worse for people struggling with depression and/or anxiety. Studies have shown a bidirectional association between sleep and mood, meaning one condition is likely to contribute to the development of the other
Short or interrupted sleep can disrupt the body’s schedule or circadian rhythm. This leads to sluggishness, fatigue, and fogginess. These conditions further impact one’s ability to do cognitive tasks in the daytime. Once the circadian rhythm is off balance, it can impact important activities like memory consolidation and information processing.
Daytime stress, anxiety, or depression may amplify the mental and physical fatigue factors of poor sleep. Even brain functions change with poor sleep (less than seven hours or fragmented sleep). Important cellular processes take place during deep sleep (i.e. slow wave sleep). When interrupted it can disrupt daytime cognitive functioning. Extended periods of poor sleep may result in inflammation which hinders the clearing away of cellular debris. Poor cognitive functioning is a result of ineffective brain structure at the cellular level. Furthermore, stress, with its bodily responses, intensifies the effect. Peak cognitive performance has been associated most strongly with seven hours of sleep in young adult and adult populations.
Strategies to Improve Sleep
Behaviors to improve sleep health include:
- Stick to a Sleep Schedule: Going to bed and waking up at the same time every day helps regulate your circadian rhythm, making it easier to fall asleep and wake up naturally.
- Create a Positive Sleep Environment: Aim for a dark, quiet room with a comfortable bed. Avoid electronics before bed, mental stimulation can make it harder to fall asleep.
- Limit Caffeine Before Bed: Try to avoid caffeine in the hours leading up to bedtime, as it can keep you awake.
- Get Enough Sleep: Aim for seven to nine hours of sleep each night. Getting a full night’s sleep helps your brain perform at its best the next day.
- Exercise Regularly: Physical activity during the day can help improve sleep quality. Make sure to avoid intense exercise right before bed, as it might keep you awake.
- Get Morning Light: This signals to the brain that the sleep phase has ended, and it is time for the wake phase.
- Use Cognitive Behavioral Therapy (CBT): A sleep specialist can guide you through techniques to relax the mind using CBT. Studies report higher levels of happiness from respondents using CBT and as well as an association between CBT and improvements in learning and sleep health.
Improving Sleep and Cognition
Sleep, exercise, and diet are the three pillars of health. Improve sleep quality with seven to nine hours of sleep and minimize wakeup times. This can elevate mood and reduce the blunting of cognitive abilities. Short and long-term benefits from CBT are achieved when paired with strategies to improve sleep.
When you improve your sleep quality, you don’t just feel better, you perform better too. People who sleep well tend to be more focused, have better memory, and are able to manage stress more effectively. Plus, getting good sleep can help improve your mood, making you feel happier and more energized throughout the day.
Kathy Sexton-Radke PhD is a psychologist specializing in sleep medicine at the University of Chicago Adventist Hospital and Allied Medical Staff/Elmhurst University professor. She is also a member of the World Sleep Society.