Sleep Debt: Memory & Performance

Updated: Aug 10

Memory is quintessential to learning. As part of the human learning process, memory consolidation is needed to support the storage of enduring memories. Therefore, sleep is critical for memory and learning. However, sleep deprivation is one of the greatest challenges for students. Sleep deprivation has been identified as a global epidemic with a myriad of negative consequences on cognitive function, psychological well-being, and physiological health (Lyon, 2019).

Red alarm clock

Sleep debt is defined as getting fewer than the recommended hours of sleep needed. Simply sleeping in on the weekends will not erase slept debt that accumulates over many nights. It is essential to know how much sleep you should be getting. It is also important to understand the negative effects that sleep debt has on cognitive function, psychological well-being, and physiological health. For students, this is particularly important since sleep debt impacts learning, memory, and health. Sleep debt also effects educators.

How much sleep is recommended?

The Center for Disease Control (2017) provides sleep recommendations based on hours per day and age groups (see Table 1).

Table 1

Recommended Hours of Sleep Per Day, CDC

Table showing recommended hours for sleep across age groups

It is important to review what national data reveals about sleep deprivation for students and educators in the United States. The following citations provide an overview why understanding sleep debt is so important to the well-being of students and educators. Note: Data is pre-pandemic.

  • "The CDC estimates that an estimated 83.6 million U.S. adults sleep less than 7 hours" (American Academy of Sleep Medicine, 2016, para. 3)

  • "80% of college students get less than 7 hours of sleep on average" (Breese, 2020; see Figure 1).

  • "Up to 60% of all college students suffer from a poor sleep quality, and 7.7% meet all criteria of an insomnia disorder" (Schlarb, Friedrich & Claben, 2017).

  • "72.7% high school students (grades 9-12) did not get enough sleep on school nights" (CDC, 2020).

  • "Sleep deficit stats prove that 60-70% of American teens live in sleep debt" (Jacimovic, 2020, para. 47).

  • “College students rank sleep problems as the No. 2 cause of difficulties with academic performance. Stress is No. 1(Emerson, 2018).

  • "Teachers and staff slept an average of 6.6 hours per night and 48 percent slept six or fewer hours per night" (American Federation of Teachers, 2017).

Figure 1

Number of Hours College Students Sleep by State

Map of USA with hours college students sleep per state

It is important that educators and students understand the profound negative effects of sleep deprivation on cognitive function, psychological well-being, and physiological health. The data below provides critical insight into the effects of sleep deprivation that have short and long-term consequences on the brain and body.

Cognitive Function

  • “Being sleep-deprived impacts the skills needed to do well on tests, like memory recall and concentration” (AASM, 2021, para. 2).

  • “Getting six-and-a-half hours of sleep every night resulted in grades that were 50 percent lower than students who averaged just one more hour of shut-eye each night” (Kekatos, 2019).

  • “College students who pull “all-nighters” are more likely to have a lower GPA” (AASM, 2017, para. 8).

  • “Students who stay up late on school nights and make up for it by sleeping late on weekends are more likely to perform poorly in the classroom” (AASM, 2017, para. 8).

  • “After two weeks of sleeping six hours or less a night, students feel as bad and perform as poorly as someone who has gone without sleep for 48 hours” (AASM, 2017, para. 2).

  • “People with sleep problems were found to have an approximately 1.5 times greater risk of Alzheimer’s disease than those with normal sleep” (Lyon, 2019, para. 1).

  • "Just one night of sleep deprivation can lead to accumulation in the brain of the beta amyloid protein, a key component in risk for Alzheimer's disease (American Heart Association, 2020, para. 4).

Psychological Well-Being

  • Anxiety causes sleeping problems, and new research suggests sleep deprivation can cause an anxiety disorder” (Anxiety & Depression Association of America, 2020, para. 6).

  • Sleep deprivation can worsen anxiety, spurring a negative cycle involving insomnia and anxiety disorders” (Sleep Foundation, 2020, para. 1).

  • Sleep deprivation affects your psychological state and mental health." (Harvard University, 2021, para. 1).

  • "44% of students experience symptoms of depression” (Mayo Clinic, 2021, para. 6)

  • 80% of students feel overwhelmed by academic responsibilities, and 50% have struggled with anxiety” (AASM, 2021).

Physiological Health

  • Chronic poor sleep may increase the likelihood of developing dementia, heart disease, type 2 diabetes, obesity and even cancers of the breast, colon, ovaries and prostate” (Johns Hopkins University, 2021, para. 2).

  • Another recent study found people who slept fewer than six hours a night – compared with those who slept six to nine hours – had a 20% higher risk of heart attack” (American Heart Association, 2020, para. 7).

  • Lack of sleep is a major predictor of 'all cause mortality' including cancer, Alzheimer's, heart disease, stroke, diabetes, depression, and suicide” (Syndney Sleep Center, 2019).

  • “Children and adolescents who do not get enough sleep have a higher risk of obesity, diabetes, injuries, poor mental health, and problems with attention and behavior” (CDC, 2020, para. 1).

The reality is that sleep is underrated and undervalued. Students and educators need to understand the important connection between sleep, academics, and health. Research on sleep reveals consolidation is critical to the formation of memories. Born and Wilhem (2012), describe two types of memory consolidation: “synaptic consolidation, refers to changes of synaptic connections in localized neuronal circuits” (p. 193) and “system consolidation which takes place preferentially off-line during sleep, because this type of consolidation involves the reactivation of fresh memory representations to promote their redistribution to the long-term store” (p. 193). It is important to note that synaptic consolidation occurs rapidly after a learning experience, ranging from minutes to several hours, while system consolidation can take much longer to complete and may range from days to years or decades (Baars & Gage, 2010).

Educators and students need to also understand the positive effects that sleep has on learning. There is extensive research that highlights the connection between sleep and learning which is critical to academic performance.

  • Sleep has been shown to be critical for the transfer and consolidation of memories in the cortex” (Langille, 2019, para. 18).

  • “Sleep is very important for consolidating memories. In any sort of experimental setting, study results show better performance if you learn material and then sleep on it, instead of remaining awake” (Harvard Summer School, 2021, para. 28).

  • When you learn something new, the best way to remember it is to sleep on it. That’s because sleeping helps strengthen memories you’ve formed throughout the day. It also helps to link new memories to earlier ones.” (NIH, 2013, para. 1)

  • Get a good night’s sleep before learning. Lack of sleep can cut learning ability by up to 40%” (NIH, 2013, para. 12).

  • “We’ve learned that sleep before learning helps prepare your brain for initial formation of memories. And then, sleep after learning is essential to help save and cement that new information into the architecture of the brain, meaning that you’re less likely to forget it” (NIH, 2013, para. 3).

  • "Sleep reduces stress. A good night's sleep can lower blood pressure and the elevated levels of stress hormones that are a natural result of today's fast-paced lifestyle" (Cornell Health, 2021, para. 3).

Research indicates that sleep is critical to memory, learning, health, and performance. You are encouraged to watch two short videos in which Dr. Matthew Walker, Director of the Centre for Human Sleep Science, at University of California Berkley, speaks about the effects of sleep deprivation on the brain and body as well as the effects of sleep deprivation on learning. You can also visit Dr. Walker’s website to learn more about the connection between sleep, learning, and optimal performance.

Dr. Matthew Walker

As you are designing your courses, activities, and assessment, remember to consider time and workload as factors. The focus on quality over quantity is important to support practice, reflection, and time for memory consolidation.

Author: Dr. Kristen Betts

Learn more about how INTERACT123 can support your work with designing courses that support innovative learning, memory, consolidation, and transfer.