Computer risk

Susan Greenfield, the eminent neuroscientist and head of the Royal Institution, is the latest to weigh into the debate, warning that young people's brains may be fundamentally altered by internet activity.

While concerns about children and computers have usually focused on their forging inappropriate relationships online, or failing to get enough exercise as a result of being glued to a screen, the baroness suggested the consequences may be more profound.

She told peers in the House of Lords it would be worth considering whether the rise in autism - a condition marked by difficulties forming attachments - was linked to the increasing prevalence of screen relationships.

Real-life conversations "require a sensitivity to voice tone, body language and perhaps even to pheromones - those sneaky molecules that we release and which others smell subconsciously.