Except that this would be a mistaken conclusion in this case because, as Sacks reminds us, writing was invented only around five thousand years ago, far too recently to have affected our brains. In fact, most of us don't have to look back more than several generations to find ancestors who couldn't read.

How, then, do we have reading areas for a brain that didn't evolve to read?

Stanislas Dehaene, neuroscientist and author of Reading in the Brain, argues that our brains have undergone "neuronal recycling," where writing has shaped itself over time to be easy on our visual systems.

And what's the trick to getting writing to fit into our illiterate visual system?

In my own research I have suggested how it happened: culture shaped letters to look "like nature."

Oliver Sacks describes the research this way:

"Such a redeployment of neurons is facilitated by the fact that all (natural) writing systems seem to share certain topological features with the environment, features that our brains have evolved to decode. Mark Changizi and his colleagues at Caltech examined more than a hundred ancient and modern writing systems, including alphabetic systems and Chinese ideograms, from a computational point of view. They have shown that all of them, while geometrically very different, share certain topological similarities. (This visual signature is not evident in artificial writing systems, such as shorthand, which are designed to emphasize speed more than visual recognition.) Changizi et al. have found similar topological invariants in a range of natural settings, and this is has led them to hypothesize that the shapes of letters "have been selected to resemble the conglomerations of contours found in natural scenes, thereby tapping into our already-existing object recognition mechanisms."

It is worth delving much more deeply here into our ability to read, where I will try to better communicate how powerful reading is, and how our brain has come to cope with a capability it never evolved to accommodate. I will take you through several topics, eventually moving more closely to what I call "nature-harnessing", the method culture used to turn our non-reading visual system into reading machines.

Super Reading Medium

Communicating with the dead is a standard job requirement for a psychic such as the infamous medium John Edward of the television show Crossing Over who claims to be able to listen to what the deceased family members of his studio audience have to say. Hearing the thoughts of the dead would appear to be a power we certainly do not possess. Surely this power must remain firmly in the realm of fiction (Edward included). However, a little thought reveals that we in fact do this all the time. ...by simply reading. With the invention of writing, the ability for the dead to speak to the living suddenly became real. (Progress in communicating in the other direction has been slower going.) For all you know, I'm dead, and you're exercising your spirit-reading skills right now. Good for you!

Before the advent of writing, in order to have our thoughts live on after we had gone we had to invent a great story or catchy tune and hope that they're singing it by the fire for generations. Only a few would be lucky enough to have a song or story with such legs (e.g., Homer's Illiad), and at any rate, if our ancestors were anything like us, their greatest hits probably tended to include "ooh-la-la" and "my baby left me" much more often than "here's my unsolicited advice" and "beware of milk-colored berries." Getting your children to be your audio tape in this fashion is probably futile (and aren't they just as likely to purposely say the opposite?), but at least it relies on spoken words, something readily understandable by future generations. The problem is getting your voice to last. Voices are just too light and insubstantial, like a quarterback finding an open receiver and throwing to him a marshmellow. Marshmellows are great to hold, but impossible to throw far. I suppose if you were to speak loudly enough during a heavy volcanic ash storm, ripples on the rapidly accumulating layers of ash might record your spoken words, one day to be recovered by clever archeologist decoders. However, much of what you're likely to say in such circumstances will be unrepeatable in polite company.

What prehistoric people did successfully leave behind for us to read tended to be solid and sturdy, like Stonehenge or the moai statues of Easter Island. These were quarterback passes that got to the receiver all right, except that now the quarterback is throwing something that is uncatchable, like porcupines or anvils. Massive monuments are great if your goal is to impress the neighboring tribes or to brag to posterity. But if your goal is to actually say something that can be understood, this tact is worse than writing abstruse poetry, and literally much heavier. The only thing we're sure of about such communications is that they had too much free time on their hands. Not the most informative spirit-reading.

The invention of writing changed spirit-reading forever. It also changed the world. Reading now pervades every aspect of our daily lives, so much so that one would be hardpressed to find a room in a modern house without words written somewhere inside. Lots of them. Many of us now read more sentences in a day than we listen to. And when we read we must process thousands of tiny shapes in a short period of time. A typical book may have more than 300,000 strokes, and many long novels will have well over one million. Not only are we highly competent readers, but our brains even appear to have regions devoted to recognizing words. Considering all this, a Martian just beginning to study us humans might be excused for concluding that we had evolved to read. But, of course, we haven't. Reading and writing is a recent human invention, going back only several thousand years, and much more recently for many parts of the world. We are reading using the eyes and brains of our illiterate ancestors. And this brings us to a deep mystery: Why are we so good at such an unnatural act? We read as if we were designed to read, but we have not been designed to read. How did we come to have this super power?