Ian Sample:

A midday nap can help pre-school children remember what they learned in the morning, according to a study by psychologists in the US.
The research suggests that carers and nurseries that phase out after-lunch sleeps may be harming children’s ability to learn, by disrupting the way their brains store memories.
Pre-schoolers who went without a midday sleep fared worse on memory tests than those who napped. They also failed to improve their scores even after a good night’s sleep, the researchers found.
The findings highlight the crucial role of sleep in consolidating memories, a process that underpins the brain’s ability to learn new information.
The children who benefited most were “habitual nappers” who would sleep when carers encouraged them to, rather than more mature children who had outgrown the need for a nap.