Nice article by Peter Naur, Turing award recipient, in the last Communications of the ACM (January 2007). He takes on the hypothesis that the human mind is nothing by a Turing machine, and tears it apart:
(…) human thinking basically is a matter of the plasticity of the elements of the nervous system, while computers—Turing machines—have no plastic elements.
Naturally, this is not the first time someone objects to this hypothesis which motivates the field of Artificial Intelligence (most famously Roger Penrose also objected with a completely different line of argument).
I’m not sure I understand why we can’t model the neural system in a Turing machine. My concern would be more to see whether we can do so in in almost O(n) time or where n is the number of neurons or another complexity metric. It would suffice that machine intelligence requires prohibitive (not necessarily NP-hard) computations for Naur’s point to hold. Even if, on paper, you could simulate a brain in O(n) time, you still have to demonstrate you have numerical stability.
He takes a shot at Natural Language Processing:
Talking of verbal `word senses’ given by `sets of linguistic contexts’ is an impossible way of describing human linguistic activity. Choosing between alternative senses of a polysemous word does not arise when people speak. (…)Typically the meaning of a word is ephemeral, entirely a matter of the particular conversation taking place.
The guy is interesting and has clearly a sizeable ego:
I have tried to have these articles published in journals, so far without any success. The present presentation, when published in the Communications of the ACM, will in fact be the first presentation of the Synapse-State Theory of mental life to appear in a journal. So I am clearly at the beginning of that twenty year period that it usually takes to have a scientific breakthrough accepted.
He is clearly a trouble-maker and I’m sure that Communications of the ACM debated whether to publish his article. But it is hard to deny publication right to a Turing Award recipient. Maybe some will regret he was awarded the prize in the first place.
I am now expecting a debate to ignite. Naur has made it clear that he expects to be around another 20 years to defend his point. This should prove interesting. Much is at stake.