London - Children who get less than nine hours of sleep a night struggle at school, research has shown.
The study assessed 142 primary pupils and compared the number of hours sleep with performance in a range of academic skills.
Most six and seven-year-olds deprived of sleep were less able to communicate and work out basic maths questions, researchers found.
Their spelling, grammar and comprehension also suffered, but their memory and ability to learn were less affected.
The study comes as more youngsters are allowed computers and TV in their bedrooms.
Ramon Cladellas, of the Autonomous University of Barcelona which conducted the study, stressed the importance of a good night’s sleep.
He said: “Most children sleep less than is recommended for their intellectual development, which is hindered because the lack of sleep cannot be recovered.
Pupils who sleep eight or nine hours have a worse performance than those who sleep nine or 11 hours, he said.
Professor Russell Foster, head of neuroscience at Oxford University, said: “It is very clear that nine to nine-and-half hours is optimum for cognitive performance in pre-teens.
“With less, they can perform standard routine tasks but to innovate and come up with solutions to complex problems, a good night’s sleep is essential.”
Adults need between six-and-half and eight-and-a-half hours sleep, he said.
“Much below five hours sleep and I’d be surprised if you could get anything decent out of a decent brain.” – Daily Mail