Their words also make it a lot easier for people to justify that shift – to convince themselves that surfing the Web is a suitable, even superior, substitute for deep reading and other forms of calm and attentive thought. In arguing that books are archaic and dispensable, Federman and Shirky provide the intellectual cover that allows thoughtful people to slip comfortably in the permanent state of distractedness that defines the online life.

Once we bring an explicit long-term memory back into working memory, it becomes a short-term memory again. When we reconsolidate it, it gains a new set of connections – a new context. As Joseph LeDoux explains, “The brain that does the remembering is not the brain that formed the initial memory. In order for the old memory to make sense in the current brain, the memory has to be updated.”30 Biological memory is in a perpetual state of renewal.

Sitting down and going through a book from cover to cover doesn’t make sense,” he says. “It’s not a good use of my time, as I can get all the information I need faster through the Web.” As soon as you learn to be “a skilled hunter” online, he argues, books become superfluous.

Whenever we turn on our computer, we are plunged into an “ecosystem of interruption technologies,” as the blogger and science fiction writer Cory Doctorow terms it.23.

Instead of requiring us to puzzle out where we are in an area, a GPS device simply sets us at the center of the map and then makes the world circulate around us.

The influx of competing messages that we receive whenever we go online not only overloads our working memory; it makes it much harder for our frontal lobes to concentrate our attention on any one thing. The process of memory consolidation can’t even get started.

Differences in brain activity have even been documented among readers of different alphabetic languages. Readers of English, for instance, have been found to draw more heavily on areas of the brain associated with deciphering visual shapes than do readers of Italian. The difference stems, it’s believed, from the fact that English words often look very different from the way they sound, whereas in Italian words tend to be spelled exactly as they’re spoken.21.

Descartes may have been wrong about dualism, but he appears to have been correct in believing that our thoughts can exert a physical influence on, or at least cause a physical reaction in, our brains. We become, neurologically, what we think.

But there is one thing that determinists and instrumentalists can agree on: technological advances often mark turning points in history. New tools for hunting and farming brought changes in patterns of population growth, settlement, and labor.

As more journals moved online, scholars actually cited fewer articles than they had before.