Answer:
Dr.Matthew Edlund is the director of the center for circadian Medicine and the author of
The Power Of Rest ...
He states....Teens need adequate amount of deep sleep to rebuild long term memory for learning and to maintain good health and fight obesity.
The above mentioned person fears the fact that the teens now spend their time in playing video games and are so attached to their gadgets / electronics that they don't rest and act as though their bodies don't nees any rest .
He means that teens are so immersed in these things that they don't sleep.
Hope you understood.