'Kids without 9 hours sleep a night suffer at school'

Researchers at the Autonomous University of Barcelona, Spain, found that children who are deprived of adequate sleep in the night were less able to communicate and work out simple maths questions at school.

Ramon Cladellas, who led the study, said: "Most children sleep less than what is recommended for their intellectual development, which is hindered because the lack of sleep cannot be recovered."

"Pupils that sleep eight or nine hours have a worse performance than those that sleep nine or 11 hours," Cladellas was quoted as saying by the Daily Mail.

For their study, the researchers assessed 142 primary pupils, aged between six and seven years, and compared their hours of sleep with performance in a range of academic skills.

Apart from having poor communication and maths skills, the children who didn't sleep for more than nine hours a night were also found to be struggling with their spelling, grammar and comprehension.

However, their memory and ability to learn were less affected, the researchers said and blamed it on the amount of time children spent watching TV and playing computer games.
"Nowadays, there is great concern because children are glued to the television, computers, and video games, but the same importance is not given to them going to bed at the same time every night," Cladellas said.

Professor Russell Foster of 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," he added.