Information

11 September 2005

I am not a number

'Information' is a slippery but seductive term. The concept of information is clearly tied up with many of the essential issues of consciousness, but it isn't easy to come up with a snappy definition which covers all the uses of the word. Paul Young says the word "has no definition that establishes its identity as a physical phenomenon valid for all its uses". His view, set out in his book 'The Nature of Information' and now handily summarised in a shorter paper of the same name, seeks to elucidate the matter and open the way to a solution of many mysteries, consciousness among them. (You can see selections from the paper on his site; to buy the whole thing costs $20.)

Others have thought that an analysis of information might be the crucial place to crack the problem, of course. David Chalmers notably included some speculative reflections on information as the basis of consciousness in The Conscious Mind. I think it may be the very ambiguity of the concept, the way it seems to have a foot in both camps, which suggests it might be the elusive bridge between the physical and the mental.

But the same ambiguity involves a considerable danger; that of switching senses in mid-stream. Now whatever vagueness may be attached to the word in general usage, it does have at least one meaning which is clear and useful, namely the sense given to it within the information theory attributable to Claude Shannon. Shannon was concerned with the transmission of messages, and his theory allows useful calculations about quantities of information, transmission channels, compression, and related matters. But this is a rather specialised and limited sense; above all, it has nothing to do with semantics or meaning. In real life the messages sent down a wire generally have a meaning, of course, but so far as this kind of information theory is concerned, the meaning is irrelevant: the message is merely a specified set of binary digits. In Shannon's sense, information is everywhere, and the chance variations in the surface of a cliff carry just as much information as one which has an inscription carved into it. This is at odds with the more normal everyday sense, in which by contrast, meaningfulness is the essence of information. In this sense, we might say that data is just numbers: it only becomes information when it has an interpretation - when it means something.

The danger, when talking about consciousness, is apparent. One of the key mysteries of consciousness is meaningfulness or intentionality; the semantics which Searle insists you can't get from mere syntax. If we start our discussion with one sense of information, it seems clear that we are talking in simple physical terms; if we then, perhaps without even noticing it, slip into the other sense, we smuggle meaningfulness into the discussion without having given a proper explanation.

Young is too clear and careful to fall into the trap quite as easily as that, but some kind of evasion along these lines remains the most obvious threat to his account. He sets out the stages of his proposed progress, however, with exemplary clarity, as follows.

1. Information, in every sense in which it is or could be used, both within and outside science, will be seen to be the exact equivalent of what generally is known as form. 2. Form will be redefined as a mass-energy or physical, rather than an abstract phenomenon. 3. The fundamental creative and control mechanisms of the universe will be seen to be embodied in its use of forms as information – i.e., all information is the processing of mass-energy forms. 4. All mental events, including cognition, feelings, volition, and all forms of consciousness, including consciousness of self, will be able to be defined as flows of mass-energy forms, and whatever it is we call mind will be seen as a wholly mass-energy, form-manipulating process. 5. The universe then can be defined as a mass-energy system that exercises its creative, control and communication functions by manipulating forms of itself – i.e., structures, patterns, shapes and arrangements or organizations of matter, many of which retain their identity through inward and outward flows of mass-energy, allowing us to see ourselves as forms of a self-organizing, self-controlled, mass-energy universe. As physicist, Victor Weisskopf wrote, “Nature, in the form of man, begins to recognize itself.”

Most of these proposed steps look ambitious to me, but perhaps stage 2 is the most challenging of all. Isn't form irreducibly abstract, by its very nature?

Form is, in any case, the key concept in Young's exposition, with faint echoes of Plato. Form is constituted by sets of relations between physical (or as Young would say, mass-energy) objects, and the flow of form, expressing it with extreme brevity, is information. There is a sense in which Young seems to want to have his cake and eat it; he doesn't want form to be an abstraction, but clearly, as he acknowledges, a form has to be divorced from any particular physical expression of it, and it's rather hard to see how it can remain a concrete fact while retaining such generality of application. There's a certain form which is common to the paper text of Pride and Prejudice, a magnetic tape recording of a reading, and a stream of electronic digits which encodes a video version, but the three examples have nothing physical in common so far as I can see.

That said, the account is generally a reasonable and persuasive one. As a point of view, or a perspective, it seems unexceptional; but does it amount to a theory? I gradually came to feel that I was being offered a plausible but general account of the physical correlates of mental processes, but that the vital and long-awaited moment when the lead of mere physics turned into the gold of conscious experience never really came. There are few statements in the paper I felt strongly moved to disagree with, but I did finally part company with the author over neurons. After describing the way neurons process their inputs, and giving a quotation from Theodore Holmes Bullock ("The neuron is like a miniature person... it speaks finally with one voice, which integrates all that went before.") he declares that "This activity by a single neuron is de facto concept formation - abstraction..." Maybe it is, but I don't see how or why the activity of a single neuron can accomplish such a feat. I can see how sets of neurons in the visual system manage to respond only when presented with a line orientated a particular way, but does that amount to having the concept of a line? More seems to be required, though since I haven't read the book-length version I might, in fairness, be missing something.