Sleep is of fundamental importance to our mental wellbeing and everyday performance, with adults needing about eight hours of sleep and children needing even longer.
During adolescence, body clocks undergo a shift that can lead to later bedtimes and reduced sleep, just at the most crucial point in the educational lives of young people. This can mean that learning and memory are impaired, in some cases on a chronic basis.
Some have argued that this problem should be addressed by changing the start times of secondary schools and this is certainly feasible in countries where the traditional start time of school is very early. However, in the UK a later start time would clash with carers’ work commitments and schools are reluctant to make that shift.
Research in the York Sleep, Language and Memory group has demonstrated the critical importance of sleep for language learning.
When we sleep, brain oscillations help new vocabulary to become better integrated with our existing knowledge. This means that when we wake up, we have stronger and more useful memories of the new material.
We are conducting an ongoing Economic and Social Research Council (ESRC) project that examines this memory consolidation process in children, showing a similarly crucial involvement of sleep. Our goal is to characterise the nature of this relation between sleep and language in developmental disorders such as autism and dyslexia, where the role of sleep may be subtly different.
Given the importance of sleep to language learning we are running a small randomised controlled trial funded by the Waterloo Foundation. This will look at the impact of improving sleep for school-aged adolescents.
Rather than shifting school hours, we are assessing the efficacy of simply providing support and information to help the teenagers gradually shift their bedtime earlier, so that they can sleep longer.
The preliminary results are positive: teenagers in the sleep extension group are sleeping up to one hour longer per night compared to the control group.
Our study will help the research team to assess whether this sleep improvement translates to a benefit in the retention of new language, as well as looking at more general impacts on daily cognition and attention. For the future, our team aim to scale this trial up and look at the longer term impacts of sleep extension on multiple cognitive, academic, emotional and social outcomes.