Its certainly right to debate this more - and look at all the research and the views of a wide range of stakeholders. Generally I'm with Prof Greenfield on this one. If people were moderate in their use of video games and screen-based stuff generally perhaps there wouldn't be an issue - but many seem to be heading in the opposite direction!
BBC News - Video games debate: Susan Greenfield and Tom Chivers
Neuroscientist Baroness Greenfield claimed people who play a lot of video games can have an increase in "aggression and recklessness".
She is leading a debate in the House of Lords on Monday evening about the impact of digital technologies on the mind.
But The Daily Telegraph's science writer Tom Chivers said people can use screens and still talk to others, and research shows those with an active life in social media tend to have a more active "real life".