If you study the long history of science, it’s striking how the thought of each age is dominated by some-or-other ruling metaphor that eventually gives way to another. That’s especially true when it comes to explaining human intelligence. (You can learn how in this book.)
Ever since computer technology took off after World War II, our ruling metaphor for the human brain is that it’s like a computer—as one philosophy teacher of mine put it: “a computer made of meat.” So powerful is the metaphor that many people have come to believe the brain just is, quite literally, a computer. But what if that’s just another metaphor it’s time to get past?
That’s the thesis of Dr. Robert Epstein, a senior research psychologist at the American Institute for Behavioral Research and Technology in California. He summarizes it provocatively in a recent article at Aeon entitled “The Empty Brain.”
Of course he doesn’t mean that human brain is literally empty. It never is. What Epstein means is that the brain does not “process” and “store” information as computers do. He calls the belief that it does the “information-processing” (IP) metaphor. Put more abstractly, commitment to the IP metaphor is “[the] mainstream view is that we, like computers, make sense of the world by performing computations on mental representations of it.” What’s wrong with that?
Well, one problem is simply the reason for using the metaphor:
“The faulty logic of the IP metaphor is easy enough to state. It is based on a faulty syllogism – one with two reasonable premises and a faulty conclusion. Reasonable premise #1: all computers are capable of behaving intelligently. Reasonable premise #2: all computers are information processors. Faulty conclusion: all entities that are capable of behaving intelligently are information processors.”
Of course, exposing that argument as invalid doesn’t by itself disprove the value of the metaphor. So, what does?
It’s two facts. One is that the brain does not “store” information in neurons the way computers store data in fixed media (such as hard drives or SSDs) or “memory” (RAM or ROM). In the computer’s case, you can physically locate bits and bytes, as electromagnetically charged regions, in the media or memory. Those are representations of things we want to encode in that form. But there’s nothing remotely similar to locate in a neuron.
Epstein explains, on the basis of observations in experimental psychology and neuroscience, what actually goes on instead when we learn and have learned something. If his explanation is correct, it follows that the brain does not “process” the sorts of “information” that computers do. For there are no encoded representations to process. Nor are we going to find anything like them in the brain.
The scientific truth, as Epstein presents it, is more complicated. It’s so complicated, in fact, that the IP metaphor just gets in the way of making such progress as we can. It’s not just that the brain isn’t a computer; it isn’t even enough like a computer to make the IP metaphor useful.