It would be nice to have a high-quality link on this with a primary reference. There's hardly enough information to determine what his concern is. For example:

It would be nice to have a high-quality link on this with a primary reference. There's hardly enough information to determine what his concern is. For example: "According to Dr Sigman, unrestricted use of computers can cause a conflict between a child's ability to multi-task and to their ability to maintain attention." Which of the two does PC use supposedly undermine? And what kind of PC use are we talking about - there's a huge range from mindless internet surfing to programming.