COMMENSAL ISSUE 92

Here is my contribution to C92; a little more ambitious this time :

Erratum (C91, 32.4) : "... we knew next to nothing about chemistry" should have been "... we knew next to nothing about the chemistry of living things". That makes better sense.

Emergent Properties (C91, 32.6) : I have just finished reading an interesting article about emergent properties : "The Architecture of Life" by Donald E. Ingber in Scientific American, Jan. 1998. If I understand it correctly, he explains emergent properties in terms of "tensegrity", which is a balance between tension and compression, however these are defined at that level of organisation.

The Internet (C91, 5.9) : I did qualify my agreement. I’m not convinced that falling prices will make PCs universally accessible. Some people’s income only goes up with the "standard of living", not with average income !

Free Will (C91, 28.5ff) : I do not see why determinism should cause problems regarding people’s opinions. If I ask someone’s opinion on some matter, I know from experience that it could be wrong. Since it is only an opinion, it may be subjective and differ from my point of view. Alternatively, the other person may be mistaken (ie. he has a "fault" in his mental model of the world (haven’t we all ?)), or he may be lying - for some reason his account of things is at variance with his model of reality.

We judge another’s opinion on the basis of our previous experience of the person; failing that, on our experience of people in general, and we also cross-check with any other knowledge we have. Anything we know about the real world is ultimately empirical anyway, so is subject to the limitations of observation.

Concerning one’s own opinion - well you could be mistaken anyway - you just have to trust your own judgement as being the best you’ve got. At least no-one else has messed it up - you’ve only got yourself to blame if you’ve got it wrong !

I don’t think "free will" helps the situation anyway, because someone with free will is as free to lie or be mistaken as anyone.

Comments on "Dualism" (Roger Farnworth; C91,37-39) : What can I say? I’m impressed by this one, and find myself in agreement with most of it, though I don’t think I’m a dualist !

(... 37.2) : I would claim that hearing is also a major sense, though I don’t think that materially affects the argument, as analogous arguments can be made for hearing.

(... 37.5) : I assume that absence of experience implies absence of consciousness. I’m not sure whether that is always true. I think (as you seem to do) that memory is essential to consciousness. But it is necessary to be careful as there appear to be several distinct kinds of memory. The memory that a certain colour is called red is different in kind from the memory that I saw something red a minute ago.

(... 38.6) : I read of a similar (perhaps the same) experiment in "Consciousness - Science Tackles the Self" by Susan Blackmore in New Scientist, 1st April 1989 (I assume the date is not significant !). The experiment was by Benjamin Libet at the university of California at San Francisco. He found a "readiness potential" - indicating an unconscious brain event - 400 milliseconds before a conscious desire to act.

(... 39.3) : Years ago, I worked with computers, which had systems of "interrupts" to bring about changes in what they were doing. To start the computer inputting something, there would be an interrupt. Then the computer would start merrily reading whatever it was, simultaneously doing some calculations, say, for a different program. When the inputting was complete, there would be another interrupt, and the computer would go back to doing something again for the first program. Some interrupts would occur for faults of various kinds - such as trying to divide by zero, or a peripheral device (such as a printer) failing to respond correctly.

Perhaps consciousness does something like this for us - say, change our "script" when it is no longer appropriate; or make sure we do something when a car heads towards us; etc.

I understand there is considerable evidence that the brain is composed of several relatively independent systems.

(... 39.4 & 38.4) : As you say, we have to avoid an infinite regression of someone inside our head (the "mannequin in the brain" fallacy or something similar, it’s called, and is well known in the trade) to read our thoughts, then someone in his head, and so on. There is no need for this. I know the dangers in taking computer analogies too far, but in a computer, red might be signified by any symbol, say, a number (since everything in a computer is ultimately reduced to numbers), in some chosen memory location. The location is as important as the number in interpreting the symbol. (The computer only knows it is a colour because of where it is stored.)

Similarly, there is no red spot in the corresponding part of the brain. Other parts of the brain "know" that there is something red, and where it is, from the particular neuron(s) fired.

What remains to be done is to clarify this picture, and to find the part, or parts, of the brain involved in consciousness. The latter can only be done by studying brain damage victims, and by using sophisticated scanning machines, such as MRI scanners, to pinpoint various mental activities.

Is consciousness located in one place or is it, as seems likely, spread over many parts of the brain, like memory ?

David Taylor

David : apologies for the missing "its" from "we knew next to nothing about its chemistry" (the chemistry of "protoplasm", that is). Thanks for pointing out the article in January’s Scientific American. Yes, it does use the term "emergent property". I must say, though, that this is all very much engineering - how the robustness of cells emerges from the assembly of microfilaments, intermediate filaments and microtubules that makes up the cytoskeleton rather than from an "inflated balloon" idea and how cell deformations can be used to trigger biochemical events within the cell. However, there didn’t seem to be anything surprising emerging (no consciousness emerging from the microtubules, for instance).

Thanks also for tackling Roger Farnworth’s Dualism article - I got a minor ticking-off at Braziers for side-stepping it ! Which, sadly, I have to do again; now, I plead shortage of space as well as time.

Theo