Sleep to succeed: effects of sleep deprivation on academic performance

An estimated 40% of children aged four to 16 years old across England and Wales have sleep issues

As a primary school teacher, morning conversations with parents often revolve around how well each child slept the night before. Comments such as ‘he has been up since 2am’ and ‘she is really tired today – good luck!’, are not uncommon.

A lot has been written recently about the importance of sleep in children for academic performance, particularly around whether or not to delay school start times for teenagers to accommodate the biological changes that shift adolescents’ sleep-wake cycles to later in the day. The idea is that the delayed start is better for their circadian rhythm.

This means they are more likely to get the recommended amount of sleep for their age, feel alert during class and boost their academic performance.

Consequences of sleep deprivation

I began to question whether many of the issues I faced in the primary classroom – such as inattention, lack of motivation and disruptive behaviour – were a consequence of sleep deprivation in my pupils. This led me to review the literature investigating the effects of sleep deprivation on academic performance – here’s a round-up of what I found.

Sleep deprivation does not need to take place over a long time period for the effects to be felt.
Lim and Dinges (2010)

Sleep and academic performance

Sleep issues in children

Research shows that 40% of children aged four – 16 years old across England and Wales have sleep issues (Blunden, Lushington, Lorenzen, et al., 2004). There are many possible causes of sleep problems in children from poor bedtime routines to undiagnosed sleep disorders, such as sleep apnoea or narcolepsy.

How sleep affects cognitive processes

As teachers, we know that education depends on cognitive processes in the brain, however we receive very little training on how factors like sleep may affect cognition. ‘Cognition’ is the process by which sensory input is transformed, reduced, elaborated, stored, recovered and used (Neisser, 1967). Higher intellectual processes – such as thought, memory, language, attention, problem solving, reasoning, decision making and complex perceptual processes – are all called ‘cognitive functions’ (Albright, Kandel & Posner, 2000; Andrade & May, 2004).

These processes are important because they are what help people to perceive the world, understand and remember experiences, communicate and control behaviour (Andrade & May, 2004). Individuals who are sleep deprived usually experience a decline in cognitive performance (Pilcher & Huffcutt, 1996; Philibert, 2005; Durmer & Dinges, 2005; Lim & Dinges, 2010). This means sleep is essential for cognitive performance and learning in our classrooms.

Short-term sleep deprivation

However, sleep deprivation does not need to take place over a long time period for the effects to be felt. Lim and Dinges (2010) conducted a meta-analysisA quantitative study design used to systematically assess th of the impact of short-term sleep deprivation on cognition. They found that that short-term sleep deprivation (less than 48 hours) is harmful for most cognitive domains including attention, executive function, short-term memory, working memory and processing speed.

Interestingly, attention was reported to be the area most strongly affected by sleep deprivation (Lim & Dinges, 2010). This isn’t just detrimental for the classroom – simple sustained attention is critical in many everyday tasks where lapses in attention may pose a significant safety risk. Lim & Dinges (2010) suggest that attention problems often precede other signs of sleep deprivation; they say that attention deficits may be an ‘early warning’ system for ‘imminent cognitive failure’ (p 13).

Reviews conducted by Durmer & Dinges (2005), Lim & Dinges (2010), and Alhola & Polo-Kantola (2007) have consistently found that working memory is particularly vulnerable to sleep deprivation. Working memory involves the ability to hold and manipulate information. This results in people having difficulty determining the scope of a problem due to changing or distracting information, remembering the order of information, maintaining focus on relevant cues, maintaining flexible thinking and making behavioural modifications based on new information (Durmer & Dinges, 2005).

What are the limitations of the research?

Standardised measures

It is important to note that the studies included in the reviews used different tasks to measure attention and working memory and therefore the results are not directly comparable. Future research should aim to consistently use standardised measures of attention and working memory so that results can be compared across studies.

In many cases, the authors were also only able to obtain a small amount of unpublished data, so it is possible that there was a bias in the analysis. This is because there is a tendency in science to only publish positive results and not to publish negative results.

The age of the participants could also be a limitation. The studies selected for inclusionAn approach where a school aims to ensure that all children in the meta-analysis by Lim and Dinges, for example, included participants that were healthy adults over the age of 18 years old – and not children.

What questions does the research raise for teachers?

As teachers we demand a lot from children’s cognitive resources, especially their attention and working memory. Given the research, teachers might ask:

• Could the child who struggles to follow instructions and pay attention actually be tired?
• Would a good night’s sleep lead to a change in their performance?
• Is there anything we can do as a school to improve sleep education in children and parents? (The NHS detail how much sleep children and young people need at different ages here.)

Parents and teachers can work together by having an open dialogue about sleep.
Ryan Deakin

What ideas might you adopt for your own classroom from the research?

Given the findings of the reviewed literature, it is reasonable to suggest that sleep deprivation has a significant impact on cognitive function. It is important for teachers to consider sleep as an important factor which may contribute to the outcomes of the children we teach.

More work is needed to educate teachers about the importance of sleep so that they are able to teach children about healthy sleep routines and help to identify children who may benefit from further intervention from sleep practitioners so that they can achieve their full academic potential.

Parents and teachers can work together by having an open dialogue about sleep. This will ensure that teachers can adapt their practice as necessary and also that parents can be made aware of any issues that happened during the day that might have an impact on their child’s sleep. Teachers could allow extra time for processing delays, visual prompts to allow for memory lapses, and also modify their environment; sitting these children near a window for fresh air and light, and enough water to drink which will help stimulate them. This partnership between parents and teachers is important for ensuring that the children’s progress and learning is maximised.