The Atheist's Guide to Reality_ Enjoying Life Without Illusions - Alex Rosenberg [87]
What Kandel’s work and a lot of neuroscience going back a hundred years has shown is that, among other things, the brain is at least in part a computer. It’s composed of an unimaginably large number of electronic input/output circuits, each one a set of neurons electrically connected to others through their synapses. The circuits transmit electrical outputs in different ways, depending on their electrical inputs and on how their parts—individual neurons—are wired up together. That’s how the brain works. It’s more powerful and more efficient than any computer we’ll ever be able to build and program. Maybe the brain is a lot of separate computers, wired together in parallel along with other peripheral “devices”—the eye, the tongue, the ear, the nose, the skin. But that it is at least a computer is obvious from its anatomy and physiology right down to the individual neurons and their electrochemical on/off connections to one another.
The brain is a computer whose “microprocessors”—its initial assemblies of neural circuits—are hardwired by a developmental process that starts before birth and goes on after it. Long before that process is over, the brain has already started to modify its hardwired operating system and acquire data fed in through its sensory apparatus. What happens to it doesn’t differ in any significant way from what happens to Watson. Our brain inputs data via changes in air pressure on the eardrum (sounds, noises, words), the irradiation of light photons on the retina (gestures, images, inscriptions), and similar input from the other sense organs, instead of through magnetic or voltage changes that Watson uses. But they are all just physical processes. Just as Watson stores enough information and processes it to win at Jeopardy without any of its states being about anything at all, our brain accomplishes the same trick. Beliefs, desires, wants, hopes, and fears are complex information storage states, vast packages of input/output circuits in the brain ready to deliver appropriate and sometimes inappropriate behavior when stimulated.
The brain’s neural states, like the states of the semiconductor circuits in a Mac or PC (or in Watson for that matter), are not by themselves intrinsically about anything at all. What you have got is a lot of neural architecture geared up to respond with exquisite appropriateness to external and internal stimuli. Its responses produce characteristically human behavior—for example, making noise with your throat, tongue, teeth, and breath (that is, speaking). In addition to the many other effects inside the body that these neural activities produce, they also produce the illusion that the thoughts in there, in the brain, are really about the world. This is such a powerful illusion that it has been with us forever, or at least for a couple of hundred thousand years.
Here’s an analogy that may help illustrate just what sort of an illusion we’re dealing with. Remember, it’s just an analogy, imperfect at best.
A single still photograph doesn’t convey movement the way a motion picture does. Watching a sequence of slightly different photos one photo per hour, or per minute, or even one every 6 seconds won’t do it either. But looking at the right sequence of still pictures succeeding each other every one-twentieth of a second produces the illusion that the images in each still photo are moving. Increasing the rate enhances the illusion, though beyond a certain rate the illusion gets no better for creatures like us. But it’s still an illusion. There is nothing to it but the succession of still pictures. That’s how movies perpetrate their illusion. The large set of still pictures is organized together in a way that produces in creatures like us the illusion that the images are moving. In creatures with different brains and eyes, ones that work faster, the trick