Saltdean computer gaming pupils 'sleepy'
12 February 2013 Last updated at 20:57 GMT
A Sussex head teacher has said pupils staying up late into the night to play computer games or watch TV are turning up at school "ready to go to sleep" in the classroom by midday as a result.
Suzanne Morgan, head of Saltdean Primary School near Brighton, said on her blog that some children were "obsessed" with gaming - and urged parents to make sure that televisions and computers are turned off earlier.
Sussex child psychologist Aric Sigman said studies had been carried out which showed children's blood chemistry changed when they played video games.