I'm sure many have heard of The Shallows: How the Internet is Changing the Way We Think, Read, and Remember, by Nicholas Carr. His is not the only voice questioning what we're unwittingly doing to ourselves by fragmenting our attention (he focuses on the internet, but others talk about new technologies as a single thing), but it's hard to imagine that there is sufficient evidence for wholesale claims about this yet; the landscape (and thus the data) is just too fluid. There are, however, discrete facts which must be taken into account.
Take this bit from "Think Before You Speak", an article in The Economist by Andreas Kluth:
"The human brain has to work harder to process language and communication with somebody who is not physically present. (Conversation with passengers is much less distracting, apparently because those passengers are also aware of the traffic situation and moderate their conversation.) A study by Carnegie Mellon University using brain imaging found that merely listening to somebody speak on the phone led to a 37% decrease in activity in the parietal lobe, where spatial tasks are processed. This suggests that hands-free use of mobile phones cannot help much. Such distractions, according to one study, make drivers more collision-prone than having a blood-alcohol level of .08%, the legal limit in America. It appears to raise the risk of an accident by four times. Texting multiplies the risk by several times again."
What's interesting about this point is that the claim about the brain seems to extend to all kinds of 'remote' interactions, which is a significant chunk of what people mean when they refer to new technologies. Clearly, there are unwelcome consequences to our use of some technologies. But so far, they seem to be discrete problems, with a host of potential solutions (e.g., when I've seen this point about attention lately, it's often mentioned in tandem with an observation of work on autopiloted cars). I'm not worried - yet - about the future of We the Digital People.