Last modified on Monday, October 19, 1998, by Malcolm R. Forster

That consciousness is nothing more than a "bunch of neurons firing in the brain"

1. Reluctant to accept that a complex system can be explained by the behavior of its parts and the interactions between them.
2. How can you reduce something subjective, like our vivid experiences of ‘red’, to something objective, like neural firings? Support: Does not rule out the existence of neural correlates.
3. How can the reductionist thesis explain the existence of free will? Answer: Our free will may only appear to be free.

1. Is consciousness anything more than a "bunch of neurons firing in the brain"?

Support for the astonishing hypothesis:

1. Reductionism cannot work; ignores that reduction is a dynamic interactive process.
2. Consciousness as a substance is a category mistake. Gilbert Ryle (1900-1976) and the ghost in the machine. E.g., "N. G. gives me the creeps" does not imply the existence of the creeps. "Which building is the university" does not wrongly imply that the university exists, but it does make a mistake about the kind of category to which universities belong. "It has crossed my mind" does is not mistaken about the existence of minds, but does suggest that minds are in the same category as material things, though different in kind (dualism). Hence arises the mind-body problems concerning how these two substances interact, how do they exchange energy, and so on. Ryle thought that dualism arises from a category mistake, similar to the mistake of thinking that there is such a thing as the creeps that N. G. gives me.

1. Can the study of consciousness be reduced to neurophysiology?
2. How can one study consciousness in a scientific manner?
3. Does the fact that neurophysiological experiments are done only on anesthetized animals limit the scientific study of consciousness?
4. Can consciousness be studied by introspection? Too subjective? Not testable, or falsifiable?
5. Or is the use of some introspective evidence unavoidable?
6. Is there a theory in this science? Are there hard core assumptions in Lakatos’s sense?

1. What is observation?
2. Is observation theory-laden?
3. Is observation always a reliable source of information?
4. Is observation objective? Or are there biases that can be built into the observation? (Do we see what we expect to see?)

1. Experiments show how different pieces of information are fed into the visual system. But how are these piece put together again to produce a single visual experience, or perception?

• Is there an analogy between the way that information is processed in science and the way that information is processed by the visual system?

Popular Misconceptions about Seeing:

1. Why should we study something so effortless?
2. We want to cure something when it’s not working, but very few scientists bother asking how my brain works when I see something.

At the root of this misconception is the photographic account of seeing:

The Photographic Account of Seeing:

Since the eye works like a camera, seeing is similar to taking photographs. Therefore, the mind (or the brain) is like a photographic film.

Vision depends on:

1. What is there when you open your eyes (how can it depend on what is not there!).
2. The physical constitution of the observer.
3. The relative position of the observer and the observed, and the environment (lighting, fogginess, and so on).
4. Nothing else.

Consequences of the Photographic Account of Seeing:

1. You are not easily deceived by your visual system. "Seeing is believing." Provided that vision is not impaired, it is a reliable source of knowledge about the external world.
2. Vision is not ambiguous in any way. We all see the same things in the same environment. Vision is not subjective, and not laden with prior expectations (we don’t see what we want to see).
3. The mind is passive in observation. The mind does not construct what we see.

The Fallacies of the Photographic Account of Seeing:

1. You are easily deceived by your visual system.
2. The visual information provided by your eyes can be ambiguous.
3. Seeing is a constructive (active) process.

1. You are easily deceived by your visual system.

1. Side vision is blurry. We have the illusion of seeing clearly everywhere because we move our eyes easily and frequently.
2. Gray on a background gradient.
3. Kanisza’s triangle, illusory contours.
4. The Müller-Lyer illusion

2. Visual system can be ambiguous.

1. Different apparently square shapes produce the same 2D projections.
2. Monocular depth vision.
3. Necker’s triangle.

3. Seeing is a constructive (active) process.

1. Kanisza’s triangle.
2. Blind spot.

Conclusion:

The photographic account does not work because, roughly speaking, it would imply that your television can see. You cannot wire up your TV to sound an alarm each time a dog appears on the screen. Still less, could it ever tell the difference between a dog and a painting of a dog. It only records sequences of colored dots. It cannot interpret or understand what they mean.

The Homunculus Theory of Seeing:

Amend the photographic account slightly by supposing that there is some central "inner" intelligence that monitors and interprets the photographic record of the visual system. This can explain away all the fallacies of the photographic account.

Crick’s astonishing hypothesis is that "it’s all done by neurons", so that neither the homunculus, nor our consciousness, is needed to explain vision. But how can neurons do things as if they were done by a homunculus?