Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!wuarchive!rex!uflorida!gatech!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: lovejoy@alc.com (Alan Lovejoy) Newsgroups: sci.nanotech Subject: Re: Is uploading suicide? Message-ID: Date: 21 Jan 91 18:30:49 GMT Sender: nanotech@athos.rutgers.edu Organization: Ascent Logic Corporation; San Jose, CA Lines: 145 Approved: nanotech@aramis.rutgers.edu In article lovejoy@alc.com (Alan Lovejoy) writes: >Consider, however, this question: when a video camera records a picture on >video tape, is the information on the video tape recorded symbolically >(possibly false) or as tokens (necessarily true)? Now consider the same >question with respect to memories recorded in a brain machine. The relevance >of all this to the original subject should now be starkly clear, I think. > >Although the fact that brain machines communicate--even internally--using >symbols which can signal falsehoods proves that brain machines do store >at least some information symbolically, that fact is not sufficient to prove >that the mechanism of consciousness is a function of symbolic information >processing. However, if it can be shown that all information stored and >processed by brain machines is symbolic, it irrefutably follows that >consciousness is a function of symbolic information processing--just like >the processing that digital computers do! > >So then, are memories symbols or tokens? If memories can be false, they >are symbolic--by definition. Need I say more? To which JoSH comments: >[It should be pointed out that lying (and cheating and stealing) are not > necessarily functions of consciousness, as witness the viceroy butterfly, > the cuckoo, etc. More specifically, sending false signals is likely to > evolve in any situation where there is an agent which (a) does significant > cognitive reduction and (b) has interests opposed to those of the agent > evolving the deception. (a) simply means that you can't fool, e.g., > plants, but only things which make what we might call decisions. > You could arguably call that symbolic, but I don't. A housefly has a > fairly well-understood neural circuit that connects its visual inputs > directly to a stimulus to flight. This circuit can be "fooled"--that > doesn't mean the fly is doing anything symbolic. > --JoSH] I am not sure I understand what motivated this comment. It seems somewhat nonsequitur, so that I feel concern that JoSH may not have completely understood the original posting (which was from me, in case you did not notice). Of course, it is my responsibility as the writer/sender of the message to formulate it in such a way that it is understood. So let me amplify some things that I feel--after considering JoSH's coment, and rereading what I wrote several times--might be more clearly stated. To *formally* define what a symbol is guarantees that everyone is talking about the same subject. It provides a "discovery procedure" for finding symbols that can be applied by anyone anywhere and produce the same results. The justification for the definition I use is an important subject, but perhaps that should be addressed elsewhere. It would be possible to infer from my posting that there is some absolute dichotomy between tokens (from which information can be deduced based on natural law) and symbols (from which information can be deduced by assuming that certain "laws," "invariants," or "symmetries" were operating even though that assumption is not guaranteed to be true by natural law). I wish to explicity disabuse the reader on any such notion. Instead, conceptualize that there is a continuum stretching between pure symbolism and stark reality. Information implies choice. To send me a signal, you must be able to choose between alternate actions. That which you must do willy-nilly is not informative (that is, nothing new is learned by the observer). In order to encode a signal, you must perform optional actions. In other words, when the sole content of the message is the tokens themselves--the measurable, physical embodiment of the message--then the message is not symbolically encoded. Symbolic encoding exists when tokens mean more than just themselves. A thing is only a token for itself--not a symbol. It is only a token for those things NECESSARILY TRUE given the fact of the existence of the thing-token. But it *MAY BE* a symbol for any and all *other* things that are not guaranteed-by- natural-law antecedents, consequences or co-causalities of the thing-token. Let us return to the question of the video camera and the video tape. Is the information on the video tape recorded as symbols or as tokens? You may think that just about everyone would answer this question more or less identically. You would be wrong. It can be fun to start an argument by asking this question of a group, and watching people take sides and thrash back and forth. Obviously, EVERTHYING happens because of the operation of natural law. So why is not all information conveyed by tokens--based on the definition of token? The answer is because 1) natural law does not permit one to *uniquely* compute the actual previous state(s) of the universe, and 2) the previous (or next) state of the universe depends upon the state of the universe as a whole. Therefore, deducing a unique previous state of the universe from a token is not actually practical. One must make certain *ASSUMPTIONS* about the past history of a token in order to "deduce" what object or phenomenon produced that token. What happens to a photon depends on its environment, which varies. Consider how some extraterrestrial technical culture might try to figure out what information--if any--was on a video tape produced by our culture. It is certainly true that the video camera/recorder/tape system operates by natural law, and that therefore what gets recorded on the video tape by the camera can be predicted by applying natural law--and more importantly, it is also true that the inverse calculation can be performed: one can "deduce" what the video camera "saw" by examining the "tokens" recorded on the tape. However, what gets recorded on the tape is NOT just a function of what the camera was pointed at and the physics of the tape. It is also a function of the mechanisms in the camera and the recorder. There is more than one way of implementing a camera/recorder system, even ones utilizing significantly different physical effects/phenomena. Video tape players are able to recover the information on the tape by *ASSUMING* that the tape was recorded--and the image was encoded--by one of the many possible techniques for doing so. There is a wide variability in the qaulity, magnitude and quantity of the assumptions that must be made in order to interpret the significance of a token correctly. As the quality, magnitude and quantity of such assumptions increases, so does the degree to which the information conveyed by the token is symbolic rather than "inherent" or "necessarily true." Conversely, the fewer assumptions that must be made in order to interpret the significance of a token, the less risk one takes that the information deduced from that token will be false. It's a question of degrees of freedom. The more arbitrary (unconstrained) the relationship between information content and its carrier, the more the carrier of the information acts as a symbol. One might imagine that the extraterrestrials attempting to decipher our videotape might feel somewhat inclined to posit that the information on the tape was stored symbolically. There are just so many ways it could have been encoded!!! And so it is with the brain. There is more than one way to symbolically encode the same information. The reason we have not yet deciphered the code used by the brain for storing memories is precisely because it is symbolic. The relation between a symbol and its referent is arbitrary--that is, the symbol could just as easily refer to something else, or the referent could just as easily be referenced by some other symbol. The actions of the neurons in JoSH's housefly only have meaning in the context of the housefly as a whole. The meaning of the positions of the molecules in the synapse of some housefly neuron depend very much on the fact that they are where they are. In some other, arbitrary context, those same molecules either mean something else or nothing at all. To "decipher" the meaning of those molecules, one must *ASSUME* what their context is--or was. So the information in the housefly neural network is symbolically encoded. The bad news about symbolically encoded information is that it can be false. The good news about symbolically encoded information is that it can exist as multiple copies encoded in an infinite number of ways. -- %%%% Alan Lovejoy %%%% | "Do not go gentle into that good night, % Ascent Logic Corp. % | Old age should burn and rave at the close of the day; UUCP: lovejoy@alc.com | Rage, rage at the dying of the light!" -- Dylan Thomas __Disclaimer: I do not speak for Ascent Logic Corp.; they do not speak for me!