It's amazing you can read these words.
It took millions of years for humans, and our recent ancestors, to develop the visual and motor and auditory skills that let us function in the complex world we inhabit today. But in less than 5,000 years, a brief span in human history, we learned how to read.
And that skill, or at least our understanding of it, is still evolving.
Scientists are using some of their most sophisticated tools to peer inside the human brain to see what happens when we engage in the process of reading, and they are finding a number of surprises:
-- Reading is a very complex task that requires several different regions of the brain to work together.
-- But surprisingly, we don't use the same neural circuits to read as we grow from infants to adults. So our brains are constantly changing throughout our lives.
-- It appears possible that reading can improve the "connectivity" between the various brain circuits that are essential to understanding the written word.
-- And there is recent evidence that simply reading a good novel can keep that enhanced "connectivity" working for days, and possibly longer, after we have finished the book.
Reading is not just one of the talents we were born with, like seeing and hearing. It is a "recent cultural invention," as one researcher put it. Just a few thousand years ago, some creative human probably carved the first symbol in the wall of a cave, launching his followers on a rich, new adventure -- reading.
But not much evolutionary time has passed between that caveman's attempts to leave a message for someone else and today.
So it seems likely that we are retraining old tools, like sight, for a new purpose, like reading. Only in the last couple of decades have scientists been able to start unraveling that story, and there is still much that is unknown.
One of their main tools is functional magnetic resonance imaging (fMRI,) a scanner that allows them to see what is going on in the brains of human subjects without having to cut their skulls open.
Blood rushes to the parts of the brain that are active, thus telling researchers which areas are responsible for different functions, like dreaming, and reading, and thinking about making love.
Neuroscientists at Emory University in Atlanta have determined that just reading a gripping novel makes changes in the way the brain connects with different circuits, and most importantly, those changes last for at least five days. They may not be permanent, but that at least suggests that the rewards from reading last longer than the act itself.
Emory's Gregory Berns and his colleagues put 21 students (12 females and nine males) through an fMRI for about 30 minutes a day for 19 days to collect their data. During the experiment the participants read the 2003 novel, "Pompeii," by Robert Harris, based on the destruction of that city by the eruption of Mount Vesuvius.
The students were scanned for five days before reading the book, and five days after they had finished. During the intermittent nine days they read one chapter each evening before the scanning the following morning.
The scanner revealed a sharp spike in two neural networks after the first chapter, and that continued throughout the rest of the experiment, including the five days after the reading was over.