# Is there a credible argument that computers cannot replicate the human brain? **URL:** \ **Category:** Factual Questions\ **Created:** [December 8, 2014, 2:14pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654 "2014-12-08T14:14:32Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [December 9, 2014, 4:30am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/41 "2014-12-09T04:30:24Z")
Personally, I think we’d be better off trying to design artificial kindness and artificial wisdom before artificial intelligence. I’ll take nice over smart any day. Penny beats Sheldon. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [December 9, 2014, 4:43am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/42 "2014-12-09T04:43:35Z")
> [@EdwinAmi](#): > > I find it funny people get hung up on this. Just because the atomistic rules/mechanisms a system runs on are deterministic, doesn’t mean the system as a whole is deterministic. Three particle problem, anyone? Complexity? There is a subtle but crucial point here. If the rules are deterministic, the system as a whole **is** also. The n-body problem has no known closed form solution, but that doesn’t mean that it isn’t determined by nothing other than the initial state. Chaotic systems are the enigmatic problem. They are deterministic. But they are ill conditioned, so that even the slightest change in the initial conditions brings about wildly different outcomes. Creating a closed form solution is essentially infeasible. But critically, the system is deterministic, but there is no useful way of predicting it. This sounds like playing with words, but it isn’t, not from the point of view of free will. If the universe is fully deterministic it means that our paths in life are predetermined. That opens a philosophical and ethical can of worms so large you can drown in it. A mathematical example of the nature of deterministic systems is a hash function. Something like SHA-2. If I give you an input, the SHA-512 algorithm will generate 512 bits of output. Perfectly deterministically. However if you change a single bit in the input, the output will vary so wildly from the first hash to be unrecognisable. There is no known feasible way of predicting how. More importantly, there is no known way of working out how to create a given hash result by synthesising the input, bar brute force search. Yet clearly the process is deterministic. If you do find an input that gives the designated output, you can be sure that it always will. ---
**Author:** ![EdwinAmi](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@EdwinAmi](https://boards.straightdope.com/u/EdwinAmi)\ **Post date:** [December 9, 2014, 4:51am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/43 "2014-12-09T04:51:02Z")
ehhh… it is a semantic issue in effect, and so that doesn’t defeat free will. Deterministic people that we can’t even remotely predict is effectively free will. And frankly, on a fundamental level, the idea that the rules of the brain are deterministic is the same as saying that there’s no free will is a false conflation. It’s a deterministic system, but it can respond to conditions. Many of those conditions are themselves may not be deterministic. Even if they are, they are also unpredictable. It’d be like a computer program you could write; while computers are essentially deterministic, they can easily take into account things like weather, which is not, so even with a computer you couldn’t determine the outcome (there is a random number generator that uses weather data, for example). ---
**Author:** ![EdwinAmi](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@EdwinAmi](https://boards.straightdope.com/u/EdwinAmi)\ **Post date:** [December 9, 2014, 4:53am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/44 "2014-12-09T04:53:33Z")
I’ll even go one step above that, claiming that “our lives are predetermined” just because the rules of a system are deterministic, is essentially meaningless because of the vagaries of the nature of time. We’d need to discuss time philosophically before we could even begin to come up with exactly what we mean if we want to say something like that. The human brain can imagine possible future scenarios, but that doesn’t mean that they are fundamentally real in any way. I really doubt that such thoughts would ever have an effect on the actual laws of physics. ---
**Author:** ![EdwinAmi](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@EdwinAmi](https://boards.straightdope.com/u/EdwinAmi)\ **Post date:** [December 9, 2014, 5:00am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/45 "2014-12-09T05:00:02Z")
(cont.) The dilemma reminds me of the Objectivist claim against pro-life people: just because something is going TO BE a baby, doesn’t mean that right now it IS a baby. Time matters, but only actual time, what’s passed by. (Not that I agree fully with the Objectivist take on the issue) ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [December 9, 2014, 5:29am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/46 "2014-12-09T05:29:21Z")
> [@Francis\_Vaughan](#): > > Comparisons about computers being good at maths and not at other stuff is really missing the point hugely. It is comparing at a vastly too low a level. Existing computers are tiny in comparison with even very small brains. They also operate in a fundamentally different manner. What we get computers to do is arguably limited, not by the computer, but by us. We craft the programs that run. > > The obvious thing to do is to take the known structure and operational mechanisms of a brain and get the computer to simulate that… > Then you get the question - how would you know? The canonical answer is the Turning Test. Which isn’t all that satisfactory in many ways, but no-one has really come up with anything better. (Most people also don’t know what the proper Turing Test is, and there have been some very shoddy examples of its supposed application.)… Neural networks are an attempt to create a programming model that is similar to brain neurons. Instead of explicitly coded logic, you start with a set of random states and transitions and let the computer experiment with changing them around until you are happy with its behavior. I’ve seen this modeled with letter-grade feedback, as if the computer was a student in a school. E.g.: You: “What is 1+1?” Computer: “Pie?” You: “F!” Computer: \ “553e6332?” You: “D!” (at least it was a number this time…) Computer: \ “67?” You: “D+!” (getting closer…) Computer: \ “2.7?” You: “B!” Computer: \ “1.9?” You: “B+!” Computer: \ “2?” You: “A!” You: “Now, computer, where is the Eiffel Tower?” Computer: “45?” You: “F!” Computer: \ “764?” You: “F!” Computer: \ “oak?” You: “D-!” Computer: \ “Michigan?” You: “D!” Computer: \ “Normandy?” You: “C-!” etc. So the idea is that you could train a neural network over time the way you would teach a child. It works, a little bit. But nobody has taught a neural network to function like a human being. Also, look up the “Chinese Room” concept. It is more or less a thought argument that says that even if something appears to be intelligent, it might not be, or might not be in the way you suspect. Suppose an automated translator can translate between English and Chinese and back again. It has millions of rules as to when to use this character and when to use that one, and thousands of exceptions to those rules, and a few thousand counter-exceptions. Does the translator actually speak Chinese, in the sense of understanding it? ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [December 9, 2014, 6:31am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/47 "2014-12-09T06:31:41Z")
The idea of the big neural simulators is to somehow pre-program the neural net by scanning a known working brain. The idea that a huge neural net could somehow be taught to think ab-inito is what I am calling a cargo-cult mentality. The idea that somehow something sufficiently big will start to exhibit interesting complex behaviour as an emergent process without some form of existing structure already existing. One of the core issues with neural nets has been that it is essentially impossible to extract information from them about how they work. Not that yields insight into the problem they are being used to solve. Indeed further training of the net with more problems may significantly change the internal weights in an unpredictable manner. This hints at the problem at hand in trying to understand how a wet-ware brain works. Different individuals may have intrinsically different networks that address much the same activity - and it may be close to impossible to tell that they do by external examination of the interconnections. This gets us back to questions of information content. Indeed IMHO questions of determinacy, free will within the context of the history of the universe are best answered by looking at information content and the intrinsic limitations on information capture and content. But, that is MHO, and not pertinent to the OP. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [December 9, 2014, 8:45am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/48 "2014-12-09T08:45:06Z")
> [@Hari\_Seldon](#): > > Sorry to disagree. Penrose committed an error in elementary logic that he still has not acknowledged. Can you be more specific? > [@Habeed](#): > > Different researchers are working on the problem using different approaches. However, in general, whole brain emulation eventually intends to copy a _specific_ brain. […] To get a good image of a single human brain you need to slice it into 50 nanometer slices using several thousand expensive pieces of equipment over a period of years, then scan it would about 1000-5000 several hundred thousand dollar multi-beam electron microscopes. . I would argue that this copy wouldn’t be a computer but an artificial brain. ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [December 9, 2014, 1:52pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/49 "2014-12-09T13:52:34Z")
Thank you to **leahcim** , **septimus** , and **Indistinguishable** for ably answering the questions I posed. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [December 9, 2014, 3:11pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/50 "2014-12-09T15:11:20Z")
> [@Dead\_Cat](#): > > Can you elaborate on the two parts of your post I have bolded? He asserted that we could build a machine (or write a program) that no computer could ever compute would stop or would run forever. This is the “halting problem”. He then asserted that humans could know the answer. What reasoning is available to humans that is not avaiable to computers was never described. This is utter nonsense (unless you believe that god will come and tell you the answer). This elementary error wasn’t even original with Penrose (I think it was originally attributed to someone named Lucas). This was aired in a review of his book published in the American Math Monthly sometime in 1991 or so. Sorry the, online archives don’t go back that far and are, in any case, behind a paywall. I have heard since that he continues to spout this stuff. I can suppose only that it is religiously based. I did just find a citation for that review: Review of The Emperor’s New Mind by Roger Penrose. Amer. Math.Monthly, {\bf97} (1990), 938–942. It should be in any university library. Or maybe can be found on JSTOR, but that requires payment. Sorry, I cannot give a cite for that sorting algorithm. I read it somewhere some years ago and cannot now recall where and when. But I assure you I did read it. Perhaps if you google evolutionary algorithms you might find it. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [December 9, 2014, 3:21pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/51 "2014-12-09T15:21:19Z")
> [@KarlGauss](#): > > The OP and anyone else who’s intrigued by this issue, might find it interesting to read about ‘[The Chinese Room](https://en.wikipedia.org/wiki/Chinese_room)’ thought experiment. (The first paragraphs of the Wikipedia article summarize the central idea at least as well as I might, so just look there if you want to know more about it). > > ETA: To be clear, the Chinese Room ‘experiment’ emphasizes the difference between intelligence and understanding, or of intelligence and consciousness. Do you really think the Chinese room experiment is doable? I don’t. Just think what is being asked. That the operator of the room, while not knowing Chinese, be given instructions whereby, for any input in a language he knows nothing of, he produce an appropriate output. Short of teaching him Chinese, it seems inconceivable to me that this could be done. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 9, 2014, 3:50pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/52 "2014-12-09T15:50:46Z")
The “Chinese Room” thought experiment is bunk. Always has been. It assumes the existence of the perfect set of arbitrary translation rules. Then asks whether an effectively mindless automaton following the rules “understands” the high level result of what it’s doing. All this is classic polemic distraction and prestidigitation. Start by assuming the impossible. Then make a series of assertions operating at very different levels of meta-ness, while deliberately ignoring or papering over the level jumps you’re making. Finally, assume the desired conclusion and shout “ta DA!!!” It has always been a mystery to me why this fraud of a “thought experiment” has any persuasive power with anyone whatsoever. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [December 9, 2014, 8:12pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/53 "2014-12-09T20:12:25Z")
I thought the point of the Chinese Room thought experiment was to demonstrate the strangeness of the assertion that intelligent thought can be reduced to a set of rules. By breaking down the “program” into books and the “processer” into someone with zero insight following instructions, we’re deprived of being able to simply presume that the “black box” _somehow_ acts like a brain. The Chinese Room is simply a de-mystified computer. If you have trouble believing the Chinese Room could give a credible impression of AI, then how is a conventional computer different in principle? ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [December 9, 2014, 8:25pm UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/54 "2014-12-09T20:25:46Z")
Yes. The Chinese Room thought experiment was created by philosopher John Searle as an argument _against_ the idea of artificial intelligence. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 10, 2014, 1:54am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/55 "2014-12-10T01:54:34Z")
It’s still flawed, though. The central argument of the Chinese Room is “A book can’t think. Therefore, a computer can’t think.”. But this ignores the fact that a book is very different from a computer. For one thing, a computer has volatile memory, which a book lacks. If a Chinese-speaker outside of the box feeds in the question “What did I just say?”, there’s no one correct answer: The answer would depend on what, in fact, the Chinese-speaker actually did say. In order for the Chinese room to answer the question, it needs to be able to store all of the inputs it’s received, and use them in constructing outputs. ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [December 10, 2014, 3:20am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/56 "2014-12-10T03:20:07Z")
In Searle’s original paper, he explicitly mentions our Chinese-pretender having the use of “a lot of scratch paper and pencils for doing calculations”, which amounts to a form of memory. That having been said, the protocol he envisions is also one in which all questions arrive in one batch and then the answers are provided in one batch. But regardless, certainly the spirit of the experiment would not at all be disturbed by continuing in an interactive questioning protocol, allowing unlimited use of paper or such things as data storage along the way, according to rules prescribed by the book. The point was simply to imagine someone carrying out mechanically and blindly the instructions of a computer program, just as would the sort of computing machines we call “computers”. I’m not sympathetic to the conclusions Searle draws, mind you. I just don’t think “But what about remembering inputs?” is a very strong objection to the thought experiment. (I’ll note that in Searle’s story, inputs are provided as writing and never removed, so one automatically has a transcript available of all inputs; the reason to provide further paper is just as working memory for calculation) ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [December 10, 2014, 3:30am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/57 "2014-12-10T03:30:14Z")
Incidentally, it may be enlightening to note this passage from the original paper: > [@Minds](#): > > By way of concluding I want to try to state some of the general philosophical points implicit in the argument. For clarity I will try to do it in a question and answer fashion, and I begin with that old chestnut of a question: > > “Could a machine think?” > > The answer is, obviously, yes. We are precisely such machines. > > “Yes, but could an artifact, a man-made machine think?” > > Assuming it is possible to produce artificially a machine with a nervous system, neurons with axons and dendrites, and all the rest of it, sufficiently like ours, again the answer to the question seems to be obviously, yes. If you can exactly duplicate the causes, you could duplicate the effects. And indeed it might be possible to produce consciousness, intentionality, and all the rest of it using some other sorts of chemical principles than those that human beings use. It is, as I said, an empirical question. “OK, but could a digital computer think?” > > If by “digital computer” we mean anything at all that has a level of description where it can correctly be described as the instantiation of a computer program, then again the answer is, of course, yes, since we are the instantiations of any number of computer programs, and we can think. > > “But could something think, understand, and so on solely in virtue of being a computer with the right sort of program? Could instantiating a program, the right program of course, by itself be a sufficient condition of understanding?” > > This I think is the right question to ask, though it is usually confused with one or more of the earlier questions, and the answer to it is no. > > “Why not?” > > Because the formal symbol manipulations by themselves don’t have any intentionality; they are quite meaningless; they aren’t even symbol manipulations, since the symbols don’t symbolize anything. In the linguistic jargon, they have only a syntax but no semantics. Such intentionality as computers appear to have is solely in the minds of those who program them and those who use them, those who send in the input and those who interpret the output. > > The aim of the Chinese room example was to try to show this by showing that as soon as we put something into the system that really does have intentionality (a man), and we program him with the formal program, you can see that the formal program carries no additional intentionality. It adds nothing, for example, to a man’s ability to understand Chinese. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 10, 2014, 4:19am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/58 "2014-12-10T04:19:01Z")
But I think that once you do allow “pencils and plenty of scratch paper” that the argument falls apart. People reflexively say “A book can’t think” (or understand, or whatever), but once you include the scratch paper, it effectively is a computer, and the argument then becomes “Computers can’t think because computers can’t think”. ---
**Author:** ![Indistinguishable](https://avatars.discourse-cdn.com/v4/letter/i/90ced4/32.png) [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)\ **Post date:** [December 10, 2014, 4:39am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/59 "2014-12-10T04:39:49Z")
For what it’s worth, Searle already was willing to get rid of the book. He considers the case of a person who has memorized the rules of the book and just follows them (again, mechanically, opaquely). He thinks, for various reasons, such a person still doesn’t understand Chinese. Like you, I do not share his perspective. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 10, 2014, 4:56am UTC](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654/60 "2014-12-10T04:56:10Z")
I would argue, rather, that the person who memorized the book is not the same person as the person who knows Chinese, but that he rather has another person running on the hardware of his brain. But of course, any rulebook complex enough to model a human mind would be too complex to be memorized by a human, so saying that the man memorizes the book is yet another cheat (unless we assume that the man in the box is some form of superhuman, which makes the experiment less interesting). [Previous page](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654.md?page=2) [Next page](https://boards.straightdope.com/t/is-there-a-credible-argument-that-computers-cannot-replicate-the-human-brain/706654.md?page=4)