The Information Diet, by Clay A. Johnson. O'Reilly, 2012.

The jacket blurb states the problem:
The modern human animal spends upwards of 11 hours out of every 24 in a state of constant consumption. Not eating, but gorging on information ceaselessly spewed from the screens and speakers we hold dear. Just as we have grown morbidly obese on sugar and flour - so, too, have we become gluttons for texts, instant messages, emails, RSS feeds, downloads, videos, status updates, and tweets.
Johnson amplifies with statistics and examples, illustrating how our lives have morphed into a melange of distractions that prevent us from thinking. Insidiously, "smart" software learns what you click on most, and feeds you more of the same, and so your information diet becomes increasingly polarized without your awareness. It's the same dopamine effect that keeps you coming back to something that gives you pleasure and affirms your opinions.

His prescription for taming the onslaught of attention grabbers is designed to help us focus on what's important, mindfully select what distractions we allow, re-learn how to evaluate "spin", and develop the habit of seeking out source material and looking at the facts first-hand.

As an eager adopter of every distraction source he mentions, I have fallen prey to the very syndrome he describes. As a Librarian, I am accustomed to pointing out sources, and not foisting my own opinion on patrons who ask for help, so it was just too easy to provide what I found first, and let the patron figure it out. Now, I will remind myself to take more time to root out primary sources as well. And I'll also make the time to learn the arguments for and against major points of view, so I can form my own opinions, and not let the dopamine of affirmation guide my thinking.