Facebook, MySpace and other social networking Web sites are rewiring children's brains making them more self-centered and reducing their attention spans, a neuroscientist has warned.

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The nature of communication on the sites could stunt development of the brain, Oxford University neuroscientist Susan Greenfield said.

"We know how small babies need constant reassurance that they exist," she told the UK's Daily Mail. "My fear is that these technologies are infantilizing the brain into the state of small children who are attracted by buzzing noises and bright lights; who have a small attention span and who live for the moment."

Greenfield has previously said exposure to computer games, action movies, chat rooms and social networking sites could leave a generation with poor attention spans.

"I often wonder whether real conversation in real time may eventually give way to these sanitized and easier screen dialogues, in much the same way as killing, skinning and butchering an animal to eat has been replaced by the convenience of packages of meat on the supermarket shelf," she told the UK Parliament.

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