There is a strong body of research that supports the important role that sleep plays in the consolidation of memory and learning. Specifically, researchers have found that the specific stages of slow wave sleep (SWS) and REM sleep play a key role in solidifying declarative memory (knowing specific content) and procedural memory (how to do things such as playing an instrument or sport or simply riding a bike). Studies investigating the impact of naps for shift workers doing long haul shifts (such as pilots, and medical professionals) found that naps taken prior to a late night shift improved performance, alertness, and vigilance. Additionally, short naps taken mid afternoon can improve alertness for up to 2-3 hours. (Herschner & Chervin, 2014; Diekelmann & Born, 2010; Ficca, Axelsson, Muto, & Vittiello 2009; Ficca & Salzarulo 2004).
Sleep is an integral component to memory formation, consolidation, and application. However, these processes are not direct; they occur in a multi-step way. Memory formation begins at the acquisition stage, when your body registers a stimulus. Examples of stimuli that you may encounter as a student are watching a lecture, or reading a textbook. When your body registers this stimulus, your brain gets clued in that there is something going on that you need to pay attention to.
After this, it undergoes the stages of actual memory formation known as consolidation. Memory consolidation is essentially the process of integrating newly learned information within a framework of existing knowledge. In the consolidation stage, memories become more stable. This is a step beyond listening or reading something--this memory is starting to become knowledge that you can apply to a homework assignment or future exam.
Next is an enhancement stage, when memory is restored and additional learning is developed without a need for additional stimuli. Memories in this stage go beyond just memorization. In this stage, your memories can be applied to problem solving completely new material based on what you have already learned.
As your brain takes on new knowledge, it also changes physically. Brain plasticity is the ability of our brains to physically change as we learn new things. Sleep plays a crucial role in this process, as it’s during sleep that the brain consolidates information and strengthens connections between neurons. This makes quality sleep essential for learning and academic success in college. By prioritizing sleep, you’re not just ensuring you feel rested, but also optimizing your brain’s ability to adapt and learn effectively.
In each of the stages of sleep, your brain goes through unique processes that support its ability to adapt to new experiences. Researchers have studied brain plasticity in action during sleep, seeing changes as deep as the molecular level. This evidence drives the belief that “learning and memory are dependent on processes of brain plasticity, and sleep-dependent learning and memory consolidation must be mediated by such processes.”
Walker, M. P., & Stickgold, R. (2004). Sleep-dependent learning and memory consolidation. Neuron, 44(1), 121-133.
There are continued questions about whether the SWS (slow wave sleep) stages or REM (rapid eye movement) stages are most important to obtain the memory consolidation benefit. However, sleep that includes both these stages seems to produce the best results for improved memory consolidation. Regarding procedural memory, it was found that if you sleep on the same day of training, the long-term memory transfer (memory consolidation) produces a better result. In addition, procedural memory improvement could rely on both explicit and implicit memory processes.
Ficca, G. & Salzarulo, P. (2004). What in sleep is for memory. Sleep Medicine, 5, 225-230.
Diekelmann, S. & Born, J. ( 2010). The memory function of sleep. Nature, February, 114-126. www.nature.com/reviews/neuro.
Mednick, S., Nakayama, K., & Stickgold, R. (2003). Sleep-dependent learning: a nap is as good as a night. Nature Neuroscience, 6(7), 697-698.
Sleep’s role in memory also shows how much it can affect one’s role as a student. Learning and sleep are closely intertwined, implying that lack of sleep has the ability to affect academic success. In a study conducted on introductory psychology students, it was found that sleep was strongly associated with the academic performance of students taking full course loads. These associations were initially seen in high school age and were further studied in a cohort of college students. Participants were invited to provide responses to the Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index, and the results were analyzed for significance. Researchers conducted multiple correlational studies analyzing sleep quality and sleep propensity (the ease and ability to fall asleep and stay asleep) with different aspects of course load and academic performance. In the overall sample of intro psychology students, neither sleep quality nor sleep propensity (readiness for sleep or ability to stay asleep) was associated with GPA or academic performance. Researchers then split students into full course load and partial course load groups. Results indicated that students with a full course load and worse sleep quality were more likely to have lower grades in the Introductory Psychology class. However, the same associations between sleep quality and academic performance were not found for students with partial course loads. For many UCSB students, taking a full course load is the norm; try prioritizing sleep so that the information can be consolidated in memory and further utilized in papers and exams!
Howell, A. J., Jahrig, J. C., & Powell, R. A. (2004). Sleep quality, sleep propensity and academic performance. Perceptual and motor skills, 99(2), 525-535.
The following literature review by researchers Hershner & Chervin hypothesizes that no direct correlation between GPA and amount of time slept has been found in college students; this study takes into account that GPA is a result of many factors besides just learning. However, sleep patterns, more than total sleep time, have been found to be correlated with GPA. Specifically, earlier wake-up times and bedtimes have been associated with higher GPAs. These findings are correlational which means that there are many reasons why they could occur. Hershner & Chervin hypothesize that this association exists because character traits such as motivation or organization may influence better sleep habits and GPAs. Alternatively, school schedules usually require earlier wake-up times, which may put those who have an evening chronotype at a disadvantage.
Hershner, S. D., & Chervin, R. D. (2014). Causes and consequences of sleepiness among college students. Nature and science of sleep, 6, 73.
On college campuses, we can’t discuss the relationship between memory, learning, and sleep without discussing the all-nighter. Students are probably all too familiar with the practice of staying up the night before a big test or an important essay is due and cramming to get it all done at the last minute. Thus, despite the information on the importance of sleep for learning that we have gone through so far, you may be thinking, ‘but I’ve pulled an all-nighter before and it made me feel more prepared and able to concentrate during the test.’ Yet, research shows that an all-nighter not only interferes with your ability to do well on a cognitive task, such as a test, but it also interferes with your ability to gauge how well you did!
In a study conducted in 1997, researchers Pilcher & Walters gathered 44 participants from different psychology classes. They then separated participants into a non-sleep-deprived group and a sleep-deprived group. The sleep-deprived group stayed awake for 24 hours doing different recreational activities whereas the non-sleep-deprived group slept for 8 hours. The following morning both groups were brought to the same testing facility where they took the Watson-Glaser Critical Thinking Appraisal test: a test that measures cognitive performance. Researchers specifically chose this test because it is a similar cognitive task as the regular tests students take in college. They also added a 40-minute time limit to simulate the college testing experience.
There was no significant difference between sleep-deprived and non-sleep-deprived participants in mind-wandering or distracting thoughts during the morning of the test, despite sleep-deprived participants reporting more fatigue and confusion during the morning of the test than non-sleep-deprived participants.
Most importantly, Pilcher & Walters found that sleep-deprived participants did significantly worse on the test than non-sleep-deprived participants. Despite this performance gap, sleep-deprived participants reported that they put in more effort, more concentration, and reported higher self-estimated performance than the non-sleep-deprived group. In other words, the sleep-deprived group did worse than the non-sleep-deprived group on the test but was overconfident in their performance.
Thus, it can be inferred from this study that sleep deprivation interferes with cognitive assessment abilities. Without being aware of this phenomenon, it can be easy to convince oneself that all-nighters actually do help you perform better on the day of the test. The all-nighter itself seems to cause one to inflate an assessment of one's own performance.
Pilcher JJ, Walters AS. How sleep deprivation affects psychological variables related to college students’ cognitive performance. J Am Coll Health. 1997;46(3):121–126.
According to Kelly Cappello at Perelman School of Medicine, sleep replenishes our ability to learn. In particular, it is thought that stage 3 sleep (slow wave sleep) contributes to memory retention and recall. In one study, 44 participants engaged in two lessons a day, once at noon and the other in the evening. Half of the group was told to nap in between lessons. The researchers found that the napping group was able to retain the information in the evening lesson just as well as in the noon lesson, while the non-napping group declined overall in retention and concentration. Sleep works not only to consolidate the information you have just learned but to prepare your brain for new memory production later on. Next time you are preparing for a big test, try to disperse your studying throughout the week so that each session is preceded by an adequate night of sleep. Doing so will help with the overall retention of new information and may even improve your test scores!
Cappello, K. (n.d.). https://www.med.upenn.edu/csi/the-impact-of-sleep-on-learning-and-memory.html [web log]. Retrieved August 16, 2022, from https://www.med.upenn.edu/csi/the-impact-of-sleep-on-learning-and-memory.html.
As shown in the studies above, obtaining optimal results in school and other performance activities (sports, music, etc.) requires a full night of restful sleep. Commitment to sleep should be consistent in order to manage academic and performance-dependent activities. That is, set a routine for waking up and going to bed at the same time each day that enables you to get 7-9 hours of sleep per night.
This work is licensed under a Creative Commons Attribution 4.0 International License.