June Kelly reports : "Staring at the screen could harm the development of children under two"

And parents should not let older children watch videos or access the Internet in their bedrooms, says the American Academy of Pediatrics.

Children under two should be stopped from watching any TV while older children should be limited to two hours a day, it adds.

This view, expressed in research published in the academy's magazine Pediatrics, has upset those responsible for popular children's programmes such as the Teletubbies and Sesame Street.

'Babies need interaction'

The academy's media education policy statement says: "While certain television programs may be promoted to this age group, research on early brain development shows that babies and toddlers have a critical need for direct interactions with parents and other significant care givers for healthy brain growth and the development of appropriate social, emotional, and cognitive skills."

Dr Miriam Bar-on, one of the statement's authors: "Children less than two are at the peak of their brain development"

But the US marketer of Teletubbies, Ken Viselman, dismissed the research as "a bunch of malarkey", because he said it did not take into account how parents raise their children.

Paediatrician Dr Harvey Marcovitch, from Banbury in Oxfordshire, and spokesman for the Royal College of Paediatrics and Child Health, told BBC Radio 4's Today programme he agreed with the research.

But he believed Teletubbies was suitable for toddlers because it had been carefully designed to fit in with the psychology of small children.

The academy says that babies need to interact with their parents rather than a television screen.

Brain growth

If television time replaces time shared between a baby and parent, the child's physical and mental development could be impaired.

If the television is used as a baby-sitter, the paediatricians warn that young children will miss out on the development of a range of social, emotional and learning skills.

Dr Harvey Marcovitch: "An average children's programme is an image of hyperactivity"

"Research on early brain development shows that babies and toddlers have a critical need for direct interactions with parents and other significant care givers for healthy brain growth," the academy says.

The academy, which represents 55,000 child-care experts, also says the bedrooms of older children should be kept "electronic media free", so that the influence of television, videos and the Internet can be more easily controlled.

Criticism

The report suggests that paediatricians should take into account children's viewing habits as part of a broader assessment of children's health.

As well as a medical history, children should have a "media history" to which doctors could refer if problems arose in children's behaviour.

But the research has been criticised by British child psychologist Dr Anne Sheppard, who has conducted research into the impact of television on children.

She said: "The Americans are much more concerned about the impact of television on children than we are in Britain.

'Deprivation'

"It is very difficult in these studies to pinpoint television as the problem in the development and behaviour of children.

"Some programmes, like Teletubbies and Sesame Street, can have a real educational benefit.

"Of course children should not be plonked in front of the television for hours on end, but using it as an electronic babysitter for half an hour when there is a suitable programme on is fine.