How does reading work biologically? In a nutshell—and the brain is shaped like a kind of walnutty nutshell, after all—your parietal lobe disengages you from what you were just doing to draw your attention to the words. Your midbrain moves your eye along them, and your thalamus focuses your attention on each letter or word that you’re reading. From within the cingulate gyrus, your eyes are directed to each of the words, and then your brain checks to see if the word you’re reading is familiar or comprehensible.
Just as a web browser caches parts of a website for faster access later, your brain does the same thing for words. There are caches of visual word-forms for your reference in the part of the brain called area 37 of your occipital-temporal region. Your temporal lobe then translates these symbols into sounds, and the anterior gyrus in the back of your head converts these sounds into your interior monologue, the voice you hear inside your head. Your left temporal lobe and right cerebellum and Broca’s area are all brought to bear on making meaning out of this flow of sounds.
It’s a complex sausage factory that fits inside your skull, and it moves swiftly, taking no more than 100 milliseconds per word and often less, as long as nothing gets in the way. As long as there are no distractions like strange flickers or ghosts, what you see on an e-reader is just as meaningful to your inner monologue as what you read in a printed book.
Okay, that was all very technical. So let me emphasize the important thing: there’s no cognitive difference in reading a sentence in a print book versus a digital book.
However, there’s more to a book than the sentences inside it. After a lifetime of habitual reading, your brain is used to considering the whole page of a book in its entirety. Your brain is used to having a dialogue, if you will, with the typographer and page layout artist of the book you’re reading. That’s why the occasional use of a new font or a drop-cap—or heck, even an italicized word—helps you stay focused. It keeps your brain from yawning and switching to something else. With e-readers, though, this dialogue often stutters. The digital page is often bereft of nuance, of any anchor besides a list of monotonously formatted words, like plain black beads on an invisible string.
When you talk to neuroscientists about how the brain works, they’ll tell you that a book is meaningless if you don’t actively engage with it. That’s why poets use unexpected word combinations, or why Friedrich Nietzsche used irony, or why David Foster Wallace used footnotes. These touches disorient you as you read, forcing you to put 10.5 watts of energy into the reading process to actually focus on what you’re reading. Why did I say 10.5 watts? It could have been any number, but it was unexpected. It got your attention, and you’re more likely to remember this passage now than you would have been if I wrote it in a dry, journalistic way without any memorable facts to catch your attention.
There’s something important and touching about the palpable physical presence of a book: it engages the senses. In this way, the act of turning pages helps to anchor information, because we have a visual, geometric sense of where one page is in relation to all the others in a book, a tactile dog-eared map. This is something we lose with e-readers. We’re used to processing a 3D world around us in everyday life, and while many e-readers have built-in progress meters to show you where you are within a book, they’re often insufficient.
Such 2D progress meters require some mental agility to use. They’re no better than gas meters on a car, which show you’re halfway through a tank but don’t tell you how many miles or gallons you have to go until empty. By comparison, there’s no ignoring the handiness of the physical presence of a book as you hold it and the sense of achievement in knowing how far through it you’ve come.
With ebooks, we also lose the ability to flip back and forth quickly through pages, as we can in a print book. I can flip through perhaps a hundred pages per second in a print book as I look for a given passage, but even on the fastest iPad, I can only see about ten pages per second. Current e-readers are still ten times too slow to match print books in this respect.
So clearly, in some respects, print books are still superior to digital books. Just as we are what we eat, we are what we read. Literally. The act of reading changes the layout of the brain, rewiring it. The more your brain can engage with a book, the better the reading experience becomes, and the more you remember of what you read. And physical sensations—the texture of the paper, the smell of the ink, the raised or recessed letters on the book cover, a peeling price tag on the spine—all help center you in the reading experience and help distinguish one book from the next in your mind’s mental map.
That’s not to say that e-reading doesn’t have advantages, though. And one key advantage is the ability to store and link the books you read.
Some people take the time to meticulously write down and log each book they read, compiling a lifelong list of books that have influenced them. Digital books can not only enable all of us to keep such a list, but also help us do it better.
More than academic curiosity drives people to log the books they’ve read. In some ways, it’s an intimate journal of your mental development. It gives you a ready way to look back on yourself as you were or to retrace ideas to their origins. It may even serve as a memory aid if you’re searching for a book you know you once read but subsequently forgot. Also, the act of creating this history helps solidify what you read and anchor it in your mind. It’s like you’ve clicked the Save icon on your word processor and are more likely to recall more of what you read because you saved it to memory.
Ebooks could enable this history automatically for everyone, no effort needed. All it will take is one retailer—say, Barnes & Noble—to add a feature to the Nook that creates a website with a reading history of every Nook book you’ve read. Every time you buy a new book, it would add to that list, and you could share it with friends and brag about the books you’ve read.
But I think the biggest boon that digital reading can give us is improved contact between people through better social connections. Reading is often a private experience, and current digital books encourage readers toward even more privacy by allowing them to interact with buttons and joysticks, with toggles and keyboards, instead of directly with other people. It’s so much easier to tweet a passage in an ebook we read than to call someone up and talk about it. Digital books are in some ways hastening the lazy, solipsistic narcissism of our culture. We use our gadgets as proxies for other people and genuine human interaction. And yes, I think that’s bad.
As a species, we seem to be designed for social interaction, so taking that away leads to problems. For example, research has shown that staying socially engaged keeps a brain vital and fit. A 2001 study published by the American Academy of Neurology found that a healthy social life may cut the risk of Alzheimer’s disease by up to 38 percent. Ebooks alone aren’t responsible for reducing the quality of our social interactions—we have telephones and chat windows and Facebook feeds to “thank” for this as well—but clearly, e-reading doesn’t have to be antisocial.
However, the reading experience can change in the future. It can let you bring your friends or family into the book as you’re reading it. Digital books have the promise of giving you the choice, in the moment, of making reading public or private, depending on your mood.
I’ll give some examples of these possibilities later in the book. But I want to pause here and agree with print-book lovers out there, because yes, you’re right. Digital books aren’t quite the same as print books.