Either Lewis Mumford, writing in Technics and Civilization was very prescient in 1930, able to anticipate problems with our own new media mobile communication environments, or he hit upon a more general structural feature of modern technologies, the proliferation of their use, and their effect upon human attention and intelligence. Reading Mumford, there’s shock of recognition in the way his discussion of old new media reflects in our own “information age.” Here’s what he still has to say about our own new media:
“What will be the outcome? Obviously, a widened range of intercourse: more numerous contacts: more numerous demands on attention and time. But unfortunately, the possibility of this type of immediate intercourse on a worldwide basis does not necessarily mean a less trivial or a less parochial personality. …With the telephone the flow of interest and attention, instead of being self-directed, is at the mercy of any strange person who seeks to divert it to his own purposes. One is faced here with a magnified form of a danger common to all inventions: a tendency to use them whether or not the occasion demands” (240).
Technics & Civilization is a big book. Mumford tends to repeat himself, as for instance here, where he makes the same point as above:
One further effect of our closer time co-ordination and out instantaneous communication must be noted here: broken time and broken attention…Nowadays the screen has vanished: the remote is as close as the near: the ephemeral is as emphatic as the durable. While the tempo of the day has been quickened by instantaneous communication the rhythm of the day has been broke: the radio, the telephone, the daily newspaper clamor for attention, and amid the host of stimuli to which people are subjected, it becomes more and more difficult to absorb and cope with any one part of the environment, to say nothing of dealing with it as a whole (p.272).
Two possibilities are possible here, one cyclical the other linear.  Writing in 1930, Mumford registers the first shock of the new technologies such as the radio, the telephone, and the daily newspaper. But over the course of a generation or two, people more or less figured out how to assimilate these media into their/our daily lives. And then the introduction of new new media, like television, video games, FB, etc. opens up the same questions re: time and attention. It might take a while, but young people learn, eventually, how to absorb these new things. It’s cyclical, the shock, assimilating shock, new shock.  People really are getting dumber and dumber with each generation, as new technologies continue to stupefy us, progressively. The telephone, etc. made people dumb, the television even dumber, and the internet dumber still. People don’t read and understand things as much and as broadly as was once upon a time.
I’m more inclined to think the former is more probable than the latter. But it takes time to figure out how to absorb and assimilate these new technologies, which is also, actually, Mumford’s point, at least circa 1930. Mumford in his later writings became much more pessimistic about technology. But bear in mind that Mumford, even back in the 1930s when he embraced what he called neotechnics, remained pretty clear eyed. I am struck by how much the structural contour of the argument back then pretty much holds today. The key, I think, has probably to do with learning how to shut off the machine in a regular, rhythmic way, and learning how to do so in such a way that it becomes second nature.