God Soul Mind Brain

machinery for social perception in a mosquito. How about a fish? Again, probably not. How about a dog? Almost certainly. Dogs have a capacity for complex social perception. How about a space alien that lands on Earth? Too bad for the alien, we’d have to run a few psychological tests and then dissect him to study his capacity for social perception.

Consciousness is a process, not a thing

    Where does this discussion leave us? We have gained a great deal of ground on consciousness. We have hemmed it into certain brain circuits (to be discussed in greater detail in the second half of the book) and linked it to the process of social perception. Consciousness is described here not so much as a thing inside us, but as a process of building a perceptual model and then searching that model in order to answer questions about it. The explanation is directed more at how people report that they are conscious, rather than at what consciousness is.

    I am reminded a bit of my son’s third birthday. He woke up, ran to the living room, and excitedly tore open his presents. Halfway through he stopped, looked at the various cars and Dr. Seuss books, and said in astonishment and dismay, “But where’s my birthday go? Where’s my birthday?” He evidently thought that a birthday was a thing he was going to receive, rather than a day-long process. In a similar way we are used to thinking of consciousness as a thing floating inside of us rather than as a process. But it seems to fit the characteristics of a process better.

Chapter 5

    Qualia

    Eventually everyone who writes about human consciousness must face the perennial question: how do we explain qualia?

    To start with, what are qualia (singular: quale)? In brief, “qualia” is the name given in philosophy to the inner, private experiences attached to perception. The most commonly discussed example is color. When you look at red, you experience a “redness” quale and when you look at blue you experience a different, “blueness” quale. One of the conundrums of philosophy is that your private experience of “redness” might be different from mine. There is no way for me to directly compare my qualia to yours. Qualia are, by definition, private experiences that can never be measured and never compared. For this reason, most scientists and philosophers believe that the very concept of qualia is resistant to science—that it cannot be explained in a mechanical or reductionist way. However, it may be possible to resolve the issue of qualia in a simple, logical fashion, which I will get to at the end of this chapter.

    I see two main ways to incorporate qualia into a general brain-based theory of consciousness. Of the two speculations, I find the first intriguing, but the second more compelling.

Speculation 1: Qualia are ubiquitous

    Let us suppose without explanation and without proof that all information processing comes with private qualia. It comes with conscious experience. In Speculation 1, when a flight computer calculates the correct flap angle for an airplane, it experiences a quale of making that calculation. When a microwave computes the time to turn itself off, it experiences a quale of “turn off now.” These experiences are not easily recognizable as mind . After all, these simple devices don’t have any sense of self, because they are not built to compute the boundary between themselves and the rest of the world. They can’t report that they have experiences, because they are not built to report anything. They can’t talk to you because they don’t have any language circuits. But in Speculation 1, they do have a rudimentary consciousness. They are aware of something , if not very much. This view has been championed by the philosopher Chalmers.

    Now consider a human brain. We want to know whether any part of Betsy’s brain is conscious. In Speculation 1, her eyeball is conscious. Why? Because it contains a network of neurons layered onto its inner wall, making elaborate computations about the visual world. If it has computations, then it has qualia. It can’t report on its experiences. It can’t talk. It can’t understand questions. It doesn’t know about itself. But it has some rudimentary conscious experience.

    Her spinal cord is conscious in the same way. It is computing, sending information up and down between the brain and the rest of the body, filtering that information, controlling reflexes. It has quite a lot of computations to