Thomas Ash

Many theories have been put forward to explain the relationship between what we call your mind (defined as the concious thinking 'you' which experiences your thoughts) and your brain. In fact, it's fair to say that this is one of the fields of philosophy which is most up in the air (though, of course, all of philosophy is up in the air to some greater or lesser extent!)

However, it's also one for which the advancing discipline of neuroscience holds out some hope of a solution. In the last half of the 20th century we have learnt how to actually 'see' thoughts play out in the brain on magnetic imaging devices which show activity in different areas of the brain. We have learnt which parts of the brain perform which functions, although 'narrow localisation' as in once-popular phrenology is of course an oversimplification.

To some this has seemed to point to epiphenomenalism. Epiphenomenalism is the idea that conciousness is simply an effect of neural events in your brain. If you can see thoughts go on in the brain, the modern reasoning goes, and they seem to follow certain logical patterns as activity in one area of the brain (say recalling a memory of a pleasant meal) causes activity in another (feeling the emotion of pleasurable nostalgia), all thought must go on in the brain. It is in many ways an appealing philosophy of mind, seeming to solve one of the most mysterious problems in philosophy, and was very popular in the 19th century, but there is a problem with it I've come up with which seems intractable to me.

This is the problem that we can have thoughts about conciousness itself (as you are doing at this very moment.) The problem this poses for epiphenomenalism is: how did these thoughts get into your head in the first place. If the experience of conciousness is simply a kind of shadow to the light cast by the firing of neurons in the brain, then the knowledge that we are having this experience shouldn't be able to enter the causal chain of firing neurons in this place, any more than the light knows about or can be affected by the shadow it's casting.

This inexplicable entry into the chain of causes which make neurons fire also poses a problem for determinism as simply understood as the following of physical laws in the brain which make one state of all the neurons in the brain necessarily lead to the next state, and then the next state after that, and so on, all in accordance with the laws of electricity and chemistry. However, this does not deal a fatal blow to determinisnm. Most theories of determinism are more complex than that, and indeed can be made completely irrespective of any "appeal to neurons."

It does however, seem to deal such a fatal blow to epiphenomenalism. Because if conciousness is just a sort of secondary effect of brain activity, an experience it generates for the person in which it takes place, it shouldn't be able to be affected by it any more than anything else in the physical world could.

What does all this point to? Well besides showing that epiphenonalism cannot in fact be an accurate picture of the mind's relationship to the brain, it points to one of four other theories.

The first is one which may suit the more traditionally, or religiously, inclined, as well as seeming to provide something of a basis for free will. (Though it is actually only a superficial one - causes and reasons for thoughts and actions should exist just as much in the mental realm as in the physical one.) This is more or less the direct opposite of epiphenomenalism; rather than mental events being a direct result of physical ones, it is the other way round, and the brain merely reflects what is going on in the mind. But this has a lot of problems, not least that purely physical neuroscience (which contrary to popular belief is actually quite an advanced science, with ample evidential backing, and not speculative at all), seems to show that a lot of what goes on in the brain can be explained by the interaction of neurons, rather than being a puppet for a separate mind.

The second is the idea that the mind and the brain are a two-way street; perhaps most of the time it is the brain calling up memories, doing calculations in mathematics tests and so on, but the mind also provides feedback, at least in the case of letting us think about conciousness. However, this faces a problem that the first theory, 'reversed epiphenomenalism', also shares. This is of saying exactly what 'the mental' is, how it exists if it is not an effect of brain activity, the way in which it and the brain are linked and can share each other's thoughts, and how it can initiate thoughts of its own. Given that the mind is presumably taken to be a non-physical thing (if not, where can we find it?), and thus completely different from anything we have knowledge of so far, it requires a lot of explanation. It also requires some quite significant justification, on the basis that extraordinary claims (and a non-physical mind is extra-ordinary precisely because it is so different from anything else we ordinarily experience) requires extraordinary evidence.

The third theory is somewhat out there, but is worth mentioning because it provides a novel solution to the difficulty of relating the physical to the mental. This is the idea first introducing by the 18th century philosopher - and Bishop - George Berkeley, that there is no physical, and that mental events are all that exist. The reasoning behind this was that it is difficult to see how an event of one kind can cause an event of a totally different kind. And yet in the effect the physical world has on our minds, and our minds have on our decisions to interact with the physical world, they seeming do all the time. Therefore, given the choice, we should choose mental events, which are the only type of event we directly experience, and thus know for sure exist. The mental experience of a rose is thus all there is. To explain why we all experience the same rose when there is no underlying physical reality we all live in, Berkeley responded that the rose exists as an idea in the mind of God, which we are all free to access. Of course, this God's existence is in need of some additional justification beyond his being convenient for Berkeley's theory.

Berkeley's theory faces several problems, but one will suffice for now. This is that if the mental is all that exists, it is hard to see why there would be such a complex 'illusion' as the physical brain, with all the complex neuroscience that explains how it seems to think thoughts and store memories.

The fourth and final solution is that of Identity Theory. This holds that the problem of the relationship between neural and mental events is non-existent - they are in fact the same thing. At first the problem with this seems obvious: they aren't. There is a world of difference between the physical firing of a neuron and another neuron responding to this electrical signal, and a concious mental event. However, perhaps mental events, which are after all little understood, simply do equate to physical events and are an integral part of them. This would provide a convenient explanation of how we are able to think about our mental events - it simply equates to thinking about our neural events. One problem with Identity Theory is that it would imply that every physical event, from the 'decisions' of a vending machine to the action of a doorhinge, has a mental correlate. The other problem is that it is very hard to prvide evidence for: we don't have access to the mental events physical actions other than those in our brain do or do not cause.

This is a problem shared by all theories of the mind-brain relationship. Conciousness is by definition a private experience, accessible only to the person it belongs to, unlike other physical phenomena. This is what takes it outside the realm of science and the scientific method and into the realm of philosophy, though neuroscience can still make valuable contributions. Were it not for the problem of our ability to think about conciousness, epiphenomenalism would be the most obvious explanation. But that problem scuppers it, and suggests that there is some more significant reality to mental events than that of merely a shadow. Given our lack of understanding as to just what that nature is, and the scientific method's inability to tackle the question, it's best to admit that the question of how the mind and the brain are related remains something of a mystery... at least for now.

______________

See also:

For more interesting (hopefully! ) essays on philosophy, see the philosophy section of my website, Big Issue Ground.
For essays and more on atheism, see my specifically atheist website, Atheist Ground.

wordfailure

The light and shadow analogy may be unhelpful, shadow not really being something that exists but rather a way of describing absence of something else that exists. Im not prepared to concede that consciousness is a phenomenon without physical coordinates. The old analogy of epiphenomenalism as steam from a locomotive is more helpful, IMO. Not to imply that the steam from the stack effects the actions of the boiler, or is even detected by it, but that it is there in physical space to be detected. Not to imply that I'm any closer to comprehending consciousness than you. In my humble, ignorant, worthless, epiphenominal opinion your conclusions overstep the evidence. But I really enjoyed the post.

Thomas Ash

That's a good point. Come to think of it, I should really have used the analogy of a light and the light cast by it, say on a piece of paper, as this is much more a direct phenomenon, rather than, as you correctly point out, shadow which is the absence of light cast by something blocking the light. Thanks for the correction .

You said that my "conclusions overstep the evidence." Could I ask what conclusions you mean? Given you talk about your "epiphenomenal opinion", does this mean that you think epiphenomenalism is still justified. If so, how do you avoid the 'thoughts about conciousness' problem. I'm really curious.

NumberTenOx

I'll take a stab.

First, to state that conciousness is distinct from neurons firing in the brain is requires that you offer an alternative physical mechanism. Otherwise we're arguing metaphysics: how much does the soul weigh? How can something that isn't physical affect the physical?

Second, even if conciousness is simply a "shadow" of the workings of the brain that can't affect the brain, doesn't mean that the brain can't produce the idea of concousness. The reason is that the brain's production of conciousness and the mind's idea of conciousness aren't necessary the same conciousness.

Heres an example. A movie projected on a screen won't affect the projector, however the projector can produce an image of a movie being filmed and projected (e.g. the end of "Get Shorty", or even see Woody Allen's "Purple Rose of Cairo" where a movie actor comes out of the screen and interacts with characters in the "real world").

John Page

Glad you put 'see' in quotes. The MRI data on brina activity can be correlated to certain thoughts or types of thought. It seems to me we still don't know how we think.
Logical patterns? Some might think that I have not a logical thought in my head! Humans can be illogical therefore human thought is illogical - is this reasonable.

I'm puzzled by this objection, I don't see contemplation about something called the self and different than contemplating somebody else (except that one must be one's own subjective reference point). We can know that we think by asking ourselves "Now why did I do that" and analyze the way we interact with our environment. Seems to me we can think about anything we're aware of from sense data, including our own self awareness.
Inexplicable? There are many things we do not understand but (most of them?) don't seem to cause trouble for determinism.
But we are part of the physical world that experience and are aware of other parts of the physcial world.
How about supervenience as a modification of simple deterministic epiphenomenalism? The concept is the abstract life of material stuff.

Interesting web site BTW.

Cheers, John

ComestibleVenom

Tom Ash
What? That has nothing to do with it. Does a doorhinge have memory? Does it have unitary access to diverse vector transformations? Does it have time degrading information access?

No, no no. It has nothing in common with the sort of systems known as mental.

I think your whole post has it backwards. Our descriptions of internal experience, as a matter of fact, originate within the brain. As such, the problem is not that we don't have access to mental events (we do!), but that we are stuck with the idea that our access to mental events is fundamentally discontinuous with our access to other physical events. This misconception is the root of a great deal of contradiction and wasted motion in the mind sciences.

sophie

Whenever I view this problem, a basic of philosophy pops into mind!

TO KNOW ANYTHING one has to have information.

How does information about an event come to be communicated? This in itself entails information must be communicated out of itself for some other process to have acces to its condition. Logically there are only two possibilities, the first is a primary source of information and its information is a direct result of the process itself broadcasting the information. In this case a process A is composed of A1 & A2. A2 splits off and carries information about A, while A1 retains its character as A. One of the most familiar characteristics we have of A2 is decay. The second which is a secondary source of information because it is an indirect source of information is correspondent to information transferred by light.

Once we realise our universe is set up to communicate information, information about consciousness itself seems an obvious part of existence. NOTE, we are not conscious of the hardware of the brain except when we think too much and our head hurts.

In this light, I must ask you to reconsider your options and any insights you and the world may have on consciousness.

ComestibleVenom

Or when we drink too much, that tends to make us painfully aware of the physiological nature of our experience.*ack*

God Fearing Atheist

That the mind is *ontologically* distinct from what goes on in the brain is, I think, clear enough.

Otherwise, you're commited to absurd conclusions like the logical impossibility of zombies, that brain and mind are rigid designators (ala Kripke's argument against indentity theory), that a complete knowledge of neurophysiology would allow us to understand conscious phenomenon without first having experienced them (ala Jackson), and so forth.

On the other hand, substance dualism is equally silly. This is the 21st century; everyone knows (or should know) that the brain causes the mind.

-GFA

Thomas Ash

But where does the brain get its idea of conciousness from? Assuming it's not an inborn idea, it must be gained from perception somehow, but this is impossible if it's just a one-way projection of the brain.