I had trouble paying attention to “The Shallows.” At first, I thought the fault might lie in Nicholas Carr’s narrative style, which alternates between straight-talk explanation peppered with damning statistics and grandiose prediction about “the future of knowledge and culture.” But as I read, slowly and with Facebook breaks, I came to the realization that my distracted state didn’t indicate that the book was flawed — in fact, it only proved the book’s point, namely, that the Internet and its bevy of search engines, social networking sites and multiplayer games has replaced our formerly focused brains with an ineffective mush of dysfunctional synapses.

I exaggerate somewhat. Carr doesn’t maintain that the Internet has liquefied our brains, only that it has “rewired” them, re-appropriating the areas formerly used for tasks that require sustained concentration — say, your “Strange Russian Writers” reading — for use in fast, fragmented mental activities — Googling Gogol. The Internet is useful and dangerous. The Internet creates, and the Internet destroys.

Carr dredges up a lot of evidence to make his point, so much evidence that a few passages look more like spreadsheets than prose. He cites dozens of studies and news items through the end of 2009. Carr’s thoroughness, though sometimes obtrusive, ensures that there aren’t any embarrassing references to already-outré websites, a definite possibility in the lightning-fast, fad-obsessed techno-verse he portrays. Additionally, he has a demonstrably solid grasp on the modern science of brain function and, more importantly for a writer, the ability to explain it accessibly. His elucidation of brain plasticity is intriguing, if a bit wordy.

Throughout, Carr never forgets to entertain. Chapters three through five provide an amazingly continuous history of the centuries of Cassandras who, like Carr, have warned of the less-than-beneficial side effects of celebrated new technologies. The story’s span is wide, from Socrates, who fretted that the advent of books would make memory obsolete, to Joseph Weizenbaum, a 1960s computer pioneer who cautioned that the increasing capability of computers threatened our very humanity.

I enjoyed this chronology, but wondered how it aligned with Carr’s assertion that: “Rarely have we paused to ponder, much less question, the media revolution that has been playing out all around us.” Isn’t that what the last 50 pages were about? This apparent inconsistency seems inevitable in a book that makes the same point in a multitude of ways. It’s extremely convincing, and redundantly redundant. I felt the book would have made a powerful article — as it did in 2008, when Carr queried “Is Google Making Us Stupid?” in “The Atlantic.” And indeed, other authors and other publications have had the same idea; National Public Radio’s series, The Net @40, is an excellent example.

But even at a slim 224 pages, “The Shallows” is too long to maintain its focus. Carr pads it out with cute “digressions” that appear to be interesting bits of research he couldn’t shoehorn into any other chapter. This is not to say that the extra material is boring. In fact, it’s just the opposite. Mild-mannered Carr shines when he trots out some of his more evil characters, like Joe O’Shea, a Rhodes Scholar who unabashedly explains that he doesn’t read books because “I can get all the information I need faster through the Web.” Google founders Larry Page and Sergey Brin come off as full-blown mad scientists who want to replace your fallible human mind with a “smarter” artificial brain. Every bone in my English-major body quivered in fear and indignation as I read Carr’s eulogy for the printed book, the written word and pretty much everything I hold dear.

“The Shallows” is a valuable read despite its defects. There’s good stuff in here. Use your impatient, Internet-addled brain to skim through any tedious passages, plucking out relevant snippets of information. And remember, if you find yourself wandering: it’s not your fault. It’s the Internet’s. Now if only you could get off of it.