New study in the latest issue of Journal of Broadcasting & Electronic Media supports the idea of selective attention to online news.
In other words, we pay attention to stuff that agrees with our own viewpoints.
What people know often is a product of what we watch and read, but even more so it is the product of our own predisposions, our own filters, our own take on the info we consume. And then, even when exposed to info we don't like, we mess with it in our heads and twist it into something we should have heard or read. That way, it fits.
Back to the study. Graf and Aday run a series of experiments to show people spend more time reading stories consistent with their own points of view than those counter to them. Selective attention. We already know people selectively expose themselves to stuff they agree with, now we know that the echo chamber is even louder -- they attend to that with which they agree.
The result? Not in this study, but in general we know that leads to more extreme viewpoints.
This all fits the idea of a fragmenting news environment. It's easier now to spend more time with news sources that agree with our particular partisan or ideological viewpoints. While it is hard to argue with having more sources of information, the consequences are less positive.