The prestigious journal Psychological Bulletin published the results of a major study this week on the importance of sleep for children. Researchers at the Netherlands Institute for Neuroscience (NIN-KNAW) and Leiden University analysed all the research on this subject carried out in the past one hundred years . Children who get less sleep have more behavioural problems, underperform at school, and have trouble carrying out complex tasks.
Unlike in adults, children’s ability to concentrate for lengthy periods is, surprisingly enough, not improved by their getting more sleep. On the other hand, their ability to retain new information and skills does not depend on sleep as much as that of adults. These findings offer new insights into the brain mechanisms that underlie the importance of sleep for how people function during their waking hours.
The importance of sleep for the way we function during the day has become increasingly clear in the past ten years. Until now, however, the relevant conclusions concerning brain function and performance were based mainly on research involving adults. This week, the prestigious journal Psychological Bulletin posted an advance publication on its website of an article that meta-analyses research reporting on sleep in children. Rebecca Astill, a researcher in Eus van Someren’s group at NIN, worked with researchers Kristiaan van der Heijden and Rien van IJzendoorn at the Institute for Education and Child Studies at Leiden University on a summary of all the studies carried out in the past hundred years on sleep and daytime functioning. These studies involved no fewer than 36,000 children.
The meta-analysis shows that children who get less sleep perform more poorly in cognitive terms, including at school, and that they also exhibit more behavioural problems. While the results are unsurprising, this is the first time that they have been based on sound evidence. That is cause enough for concern, especially with children today getting less and less sleep on average. Interestingly enough, sleep-deprived children also demonstrate completely different patterns of sensitivity than their adult counterparts. The two behaviours that depend most on a good night’s sleep in adults, i.e. attention span and memory, are not connected nearly as closely to sleep duration in children.
To begin with, children who get more sleep are no better able to concentrate than children who get less. The researchers point out, however, that children are not very good at concentrating anyway: a well-rested child will not be able to concentrate any better than an adult who has been up all night. In addition, the connections between the frontal and parietal brain areas in children are far from fully developed, and it is precisely these connections that suffer in sleep-deprived adults and that are responsible for the negative impact on concentration.
The second surprising finding is that children depend much less than adults on sleep for remembering new facts and skills. Indeed, children may be at an advantage here: a child can probably lock new facts and skills into its brain just as easily when awake as during sleep, whereas an adult depends much more on sleep to do this.
The researchers point out that studies involving adults and children differ considerably in terms of research methods, which may also play a role in the differences identified. That is why a public Internet survey is under way regarding the relationship between a person’s normal amount of sleep and his/her performance on concentration and learning tasks. The researchers are hoping to recruit as many participants as possible; see www.slaapregister.nl.
Astill RG, Van der Heijden KB, Van IJzendoorn MH, Van Someren EJW (2012) Sleep, Cognition, and Behavioral Problems in School-Age Children: A Century of Research Meta-Analyzed. Psychological Bulletin. 2012 Advance online publication. doi:10.1037/a0028204