Sleep is a fundamental physiological process for human survival and health; however, its common deprivation is an increasing area of concern for many students. Studies have demonstrated the significance of sleep for daily cognitive function, as it strengthens the synaptic connections made during the day, storing information for long-term use.
However, with constant academic pressures, paired with students’ social pursuits and numerous extracurricular activities, sleep deprivation of adolescents is a common issue that ultimately affects their academic performance in school or university. Studies conducted by Woolcock Institute of Medical Research show that 70% of Australian students are sleep deprived due to technology, with already 40% affected by intake of at least 2 caffeinated drinks a day (Sealy Australia, 2020). With the many distractors present in our modern era, students are struggling to find the time for the necessary eight hours of sleep.
This paper will explore the relationship between negative sleep patterns and the academic performance of students, delving into the body’s response to sleep and how it is crucial students get enough sleep to aid their memory, concentration and mental wellbeing.
The Mechanisms Behind Sleep and their Importance
Adolescence is a time of physical, social and cognitive change, where students are constantly challenged with new knowledge and surroundings. In the transition from childhood to adolescence, the tendency to stay up later at night is evident, supported in studies measuring the timing of melatonin secretion in the circadian system. Studies have demonstrated that there is a biological phase delay in melatonin secretion that is associated with puberty, other than solely psychosocial or environmental factors, causing delayed sleepiness (Maheshwari & Shaukat, 2019). Despite this shift, the need for sleep is crucial for all ages, and a well-regulated circadian rhythm can benefit not only the academic performance, but general health and wellbeing of all students.
The stages of sleep and their relationship to memory has been studied for decades. According to Harvard Medical School’s Division of Sleep, the formation of long-term memory can be categorised into three steps; ‘acquisition’ being the introduction of new information, ‘consolidation’ being the process of stabilising memory, and ‘recall’ being the ability to access our conscious or unconscious for these stored memories (Harvard Medical School Division of Sleep, 2007). While the exact mechanisms connecting sleep, memory and neuroplasticity are unknown, many researchers suggest that special brainwave characteristics for different stages of sleep impact the formation of particular types of memories (Harvard, 2007).
REM is a stage of sleep characterised by rapid eye movement, increased respiratory rate and vivid brain activity involved in dreaming. It is hypothesised to be responsible for the ‘acquisition’ of knowledge, especially important for declarative memory. Declarative memory refers to the retrieval of fact-based information; a relevant quality in any subject. This was evidenced in a study involving students undertaking an intensive language course, where an increase in REM sleep was observed (Harvard, 2007). Slow-Wave-Sleep (SWS) is the deepest phase of restorative sleep with slower brainwaves, important for non-declarative memory, such as procedural or motor memory. SWS is proposed to “downscale synaptic weights to avoid saturation in memory networks” (Cousins & Fernandez, 2019), hence allowing space for storage of new information. Thus, both REM and SWS phases of sleep play important roles in memory.
Reinforcement at the cellular synaptic level ensures newly formed memories are not easily forgotten. This process is controlled by regions of the brain, known as the hippocampus and neocortex. The hippocampus, located in the temporal lobe of each cerebral cortex, compilates an individual’s experiences and learned information from different areas of the brain. The hippocampus temporarily stores this information, before sending it to the neocortex during sleep. The neocortex is involved in high-order brain functions, such as sensory perception and motor command, and is responsible for gradual accumulation of knowledge, building upon existing experiences and understandings (Cousins & Fernandez, 2019). It is the connection between the two brain regions that promotes ‘recall,’ where stored information can be retrieved upon internal or external cues.
The Consequences of Sleep Deprivation on Memory and Daytime Concentration
Lack of sleep affects students’ function in all aspects of their lives, however particularly in memory and daytime concentration. While sleep deprivation inhibits ‘consolidation’ of knowledge at night, it also impacts the subsequent day of learning. Students will be unable to understand and memorise content to their full capacity, thus affecting ‘recall’ in the future.
A study performed by Harrison and Horne, involving temporal memory, tested subjects to remember two separate sets of faces after a night of total sleep deprivation (Harrison & Horne, 2000). While the recognition of faces was unaffected, the ability to sort the faces back into their sets was impaired. Further, the administration of caffeine to did not improve the results, thus proving that memory cannot be amended through wakefulness stimulants.
Similar deficit was found when testing visual, contextual and emotional memory, where a study tested participants’ memory to recall the order of events in film clips, after watching them in total sleep deprivation (Tempesta et al., 2016). While the previous study was performed immediately after sleeplessness, the memory tests in this study were done after 2 nights of recovery sleep. Still, a 15% reduction in memory was found, thus demonstrating that knowledge learnt under sleep deprivation affects its ‘acquisition,’ leading to ineffective ‘consolidation’ for future use (Tempesta et al., 2016).
Whilst the previous two studies tested ‘recall’ from a single sleepless night, further studies were performed with subjects undergoing several nights of sleep deprivation. After only 4 nights of 5-hour sleep, the capacity to learn detailed factual information was reduced by 26% (Cousins, Sasmita, & Chee, 2018). Within the 5 hours of sleep, the brainwave diagrams had depicted that SWS phase had been entered, however REM sleep duration was significantly reduced (Cousins et al., 2018). This demonstrates that the memory consolidation capacity under SWS alone is much weaker than that of SWS and REM sleep combined, thus short sleep durations for extended periods of time greatly affects the memorisation of detailed information. Following insufficient ‘consolidation,’ the ‘recall’ of wrong information is increasingly common, thus has negative effects on our academic performance.
Lack of Sleep Affects Academic Performance
The consequences of lack of sleep on academic grades were explored in a comparison between undergraduate medical students at the University of Karachi who had subjectively poor sleep quality and good sleep quality. The 512 students who experienced poor sleep quality had a mean GPA of 2.92 ± 1.09, compared to the 285 students who experienced good quality sleep who had a mean GPA of 3.31 ± 1.49 (Maheshwari & Shaukat, 2019). It was found that “most students with lower average GPA reported very bad subjective sleep quality, had a sleep latency of 16-30 minutes, sleep duration of less than 5-7 hours, sleep efficiency of 75%-84%, and experience daytime dysfunction almost every day” (Maheshwari & Shaukat, 2019).
While the above study explored the direct association between sleep and GPA, further studies delve into the importance of extended periods of quality sleep throughout the semester, rather than erratic nights before important dates. Okano’s study compared students achieving good quality sleep of 7-8 hours a night for a month leading up to an exam, as opposed to only the night before the exam. The study did not find any additional benefit for extended sleep duration the night before the exam. However, it was discovered that “both longer sleep duration and better sleep quality over the full month before the midterm were more associated with better test performance” (Okano, Kaczmarzyk, Dave, Gabrieli, & Grossman, 2019). This reinforces the importance of continued quality sleep while the examinable topics are being taught in order to successfully consolidate the information.
Educating Students About Quality Sleep
Spreading awareness about the importance of quality sleep is crucial in guiding students towards healthier lifestyles. The effectiveness of sleep education was tested to a group of control and intervened students at the University of Michigan. The intervention involved a personalised online sleep education website “Sleep to Stay Awake,” taken over a course of 8 weeks (Hershner & O’Brien, 2018). The study showcased improved sleep knowledge and encouraged sleep-related behaviour among the intervened group of college students. Additionally, the distractors for sleep, such as electronics, were minimised, and students had less frequent night study sessions, leading to a more regular sleep-and-wake schedules (Hershner & O’Brien, 2018). Thus, the education of personal wellbeing prompts students to reconsider their lifestyles and view studying and sleep of equal importance if they are to achieve to their full potential.
While the waking brain specialises in ‘acquisition’ and ‘recall’ of information, the sleeping brain provides the optimal conditions under which knowledge ‘consolidation’ can occur, strengthening neural connections for long-term memory storage (Cousins & Fernandez, 2019). Alongside memory, the daytime concentration of students who were sleep deprived was greatly reduced, and their capacity to learn both detailed-factual information and visual images was impaired. As explored in this paper, both the qualities of memory and concentration are crucial to the academic performance of students, thus must be continually reinforced to students in educational settings. Daily quality sleep is an essential aspect of a healthy lifestyle, where its positive effects will stem into all areas of life.