Dr Anne Sheppard criticised American doctors who said youngsters under the age of two should not watch television at all and that older children should be strictly limited to two hours a day.
The US report, published in the journal Paediatrics, said exposure to television, films, videos, computer games and the Internet poses health risks to children. The report, by the American Academy of Paediatrics, said: "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."
But Dr Sheppard, who has conducted research into the impact of TV on children, said: "It is very difficult in these studies to pinpoint television as the problem in the development and behaviour of children. For every study that has indicated a link between television and violence or impaired development, there has been another that has discounted the link.
"Some programmes, like Teletubbies, can have a real educational benefit. Using it as an electronic babysitter for half an hour when there is a suitable programme on is fine."