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Science

Our Brains Don't Work Like Computers 737

Roland Piquepaille writes "We're using computers for so long now that I guess that many of you think that our brains are working like clusters of computers. Like them, we can do several things 'simultaneously' with our 'processors.' But each of these processors, in our brain or in a cluster of computers, is supposed to act sequentially. Not so fast! According to a new study from Cornell University, this is not true, and our mental processing is continuous. By tracking mouse movements of students working with their computers, the researchers found that our learning process was similar to other biological organisms: we're not learning through a series of 0's and 1's. Instead, our brain is cascading through shades of grey."
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Our Brains Don't Work Like Computers

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  • by Doc Ruby ( 173196 ) on Wednesday June 29, 2005 @08:31PM (#12946689) Homepage Journal
    Each neuron is like a tiny, slow analog DSP, feeding back FM around a base frequency (eg. about 40Hz in the brain's neural tract). The neurons have feedback among themselves locally, and send out some larger feedback in fiber bundles, signalling other clusters along the way. It's like a teeming kazoo symphony, without a conductor.
  • Newsflash (Score:5, Informative)

    by tupshin ( 5777 ) <tupshin@tupshin.com> on Wednesday June 29, 2005 @08:35PM (#12946721) Homepage
    Headline: Brains More Like Neural Nets Than Traditional Programs

    Who woulda thunk it.

    ftp://ftp.sas.com/pub/neural/FAQ.html%23A2 [sas.com]

    'Most NNs have some sort of "training" rule whereby the weights of connections are adjusted on the basis of data.'

    Insert joke about the 1980's (or 60's/50's/40's) calling). Somehow I don't think Norbert Weiner would be the slightest bit surprised.

    -Tupshin
  • huh? (Score:1, Informative)

    by guardiangod ( 880192 ) on Wednesday June 29, 2005 @08:36PM (#12946723)
    Like them, we can do several things 'simultaneously' with our 'processors.'

    How so? Last time I checked 'computer brain' (cpu) cannot do multiple operations at the same time, unless you have dual core/cpus.

    CPU just switch from one task to the other at break neck speed (yes I am ignoring pipelines and branch prediction - they are only use in streamlining the operations).

    Human brain work the same way- it may be able to take in multiple informations (sight, feel, sound, smell) at the same time, but human brain has adapted a "filtering" system for unimportant sensor input. Thus you cannot say human brain does parallelistic operations at the same time.
  • Re:huh? (Score:4, Informative)

    by Bloater ( 12932 ) on Wednesday June 29, 2005 @08:48PM (#12946821) Homepage Journal
    > Last time I checked 'computer brain' (cpu) cannot do multiple operations at the same time, unless you have dual core/cpus.

    Yes it can, many have several ALUs and FPUs, and also more than one stage in their pipelines. The above hasn't been true since sometime in the nineties at the latest.
  • by SilentChris ( 452960 ) on Wednesday June 29, 2005 @08:55PM (#12946884) Homepage
    Well, actually, from the article it sort of sounds like a multibranch computing article I read a while back. I'm not sure if Intel actually went through with this, but the idea was to have a CPU process multiple "paths" ahead of time.

    So, for example, for a simple if statement waiting on user input, part of the CPU would process the "true" result of the statement and part would process the "false" one. When the user made a decision, one would be used and one would be thrown out. In theory, computing these branches ahead of time was supposed to be faster than doing things linearly.

    Again, though, I'm not sure Intel went through with this. They were the subject of the article.
  • also worthy of note (Score:5, Informative)

    by twiggy ( 104320 ) on Wednesday June 29, 2005 @09:17PM (#12947025) Homepage
    The book "On Intelligence" [amazon.com] by Jeff Hawkins (of Palm fame) and Sandra Blakeslee is all about how the brain works, and why people's approach to AI is not going to come anywhere near emulating the brain...

    Figured it was worth mentioning given the subject matter of the thread... I liked it.. good read, if a bit dry at times...
  • by DynaSoar ( 714234 ) * on Wednesday June 29, 2005 @09:39PM (#12947128) Journal
    "In this model, perception and cognition are mathematically described as a continuous trajectory through a high-dimensional mental space; the neural activation patterns flow back and forth to produce nonlinear, self-organized, emergent properties -- like a biological organism."

    Fine, let's see the math. Let's see the trajectory calculations. How about those calculating the space? Calculating the number of dimensions the space has, and how fast that number changes over time?

    40 years ago brain scientists realized that computer architecture made a good metaphor for how the brain works. (They did NOT assume there was no feedback, contrary to the article). It made a handy and productive way to look at things so they could figure out more about what was really going on.

    10 years ago brain scientists realized that they could use the way cool chaos stuff the describe the way the brain works. Believe me, I know; I've been to the Santa Fe Institute twice. It worked particularly well for me because I'm essentially a signal analyst -- I HAVE to define a set of variables, estimate how well they work, and decide how many of my arbitrary variables to keep or throw out.

    It's still only a metaphor. And unlike the specific specific processes described by cognitive science, the dynamic system stuff remains nebulous. It claims a mathematical legitimacy which it can really claim only in concept because the actual math of the acutal operations are is beyond the abilities of anyone making the claims. The fact that it *can* be described this way is no less trivial than the fact that processes can ge grouped according to the traditional cognitive science concepts.

    Trajectories on phase space are soooooooo sexy. But if it's any good, it'll result in something more concrete than more people picking up this flag and waving it while shouting the new slogans and buzzwords. Until that happens I peg this with the study that "calculated" the "fractal dimension" of the cortex just because it has fold and folds in the folds.... so fsking what.

  • Re:Fascinating (Score:5, Informative)

    by nmoog ( 701216 ) on Wednesday June 29, 2005 @09:44PM (#12947168) Homepage Journal
    Thats why everyone needs to install this super dooper greasemonkey script: De-Piquepaille Slashdot [daishar.com]

    It blocks stories submitted by Roland. Of course, you'd have to have installed greasemonkey. Which I forgot to do on re-install and hence saw this fucking stupid article.
  • predictive branching (Score:5, Informative)

    by rebelcool ( 247749 ) on Wednesday June 29, 2005 @09:48PM (#12947202)
    Modern processors do in fact, do this. They maintain statistics on the branches and go forward on the branch deemed most likely to be taken. Its based on a simple principal - if you've taken the same branch a few times before, you're likely to keep taking it from now on. Think of how loops work.

    Granted, if the processor is wrong, it has to clear the pipeline and start anew (which is costly), but the benefits outweigh the negatives.

  • by Anonymous Coward on Wednesday June 29, 2005 @10:38PM (#12947470)

    The article seems to assume that the only type of computer is a _binary_ computer.

    No, it assumes that any computer is equivalent in computational ability to a binary computer. This is a paraphrase of the Church-Turing thesis, and it is widely accepted as being true.

  • Re:comparisons (Score:2, Informative)

    by fatman22 ( 574039 ) on Wednesday June 29, 2005 @11:06PM (#12947596)
    4 8 15 16 23 42

    I hate it when someone presents a string of numbers like that. The brain involuntarily goes into 100% utilization until the answer comes out. The sum of the differences between the first five numbers in sequence plus the fifth number equals the sixth number. 4+7+1+7=19 19+23=42
  • by Anonymous Coward on Wednesday June 29, 2005 @11:14PM (#12947637)
    It's not branch prediction, but it's related. It's actually an extreme form of speculative execution, where you execute stuff that you don't know if you're going to use. The reason why it isn't used is that you're essentially doubling your silicon requirements for a marginal gain in performance--branch prediction gets you maybe 90% of the performance gain with a fraction of the hardware (compare a simple go-this-or-that-way unit to replicating all the hardware twice or more).

    This sort of problem of execution ILP (instruction-level parallelism) to turn sequential programs into parallel programs by throwing lots of hardware at the problem topped out at around the 8 pipelines in most modern CPU cores. Hence the move towards multiple CPU cores and explicit thread-level parallelism. Like any process, you can only push things so far at one level until you need to move up to the next level of meaning to extract more than marginal gains.
  • Re:Evolution (Score:2, Informative)

    by cabjoe ( 725109 ) on Wednesday June 29, 2005 @11:24PM (#12947683) Journal
    A great intro to the subject is Steven Pinker's How the Mind Works. While it doesn't (obviously) fully explain how our brain works, it does a great job of explaining how evolution has moulded our ways of thinking.
    One fascinating nugget, humans find certain logic puzzles difficult but if equivalent questions are phrased in such a way as they become tests to detect other humans cheating, they solve them with ease.
  • Re:comparisons (Score:3, Informative)

    by mjspivey ( 896286 ) on Wednesday June 29, 2005 @11:26PM (#12947694)
    The reason one might expect mouse movements to go intially all the way to a competitor object is because when my colleagues and I recorded people's eye movements in previous research, that's exactly what they did. The mouse movements show much more clearly (than previous work) that the competition from the similar-named object is continuous rather than discrete.
  • No, they are not (Score:3, Informative)

    by autopr0n ( 534291 ) on Wednesday June 29, 2005 @11:32PM (#12947724) Homepage Journal
    Yeah, they are totaly diffrent. For example a computer would probably never try to base philosophical arguments on a slashdot blurb.

    Seriously, computers can work with things more complex then 'ones and zeros'. They can be programed to deal with shades of grey as easily (well, maybe not 'easily' but it definetly can be done)

    The fundemental part of the human brain is the neuron, and it's either firing or not. 1 or 0 just like a computer. What triggers it is a bit more complicated, but the process can be emulated by a computer, and eventualy comptuers will be fast enough to do just that.
  • Re:OH MY GOD (Score:2, Informative)

    by int999 ( 775497 ) on Thursday June 30, 2005 @12:49AM (#12948024)
    didn't claim that he did. All I claimed was that Goedels theorem "... shows [read: 'it is reasonable to conclude'] that there are some types of mathematical proofs that a human mathematician can demonstrate to be true, but a turing machine ( read: any current technology computer ) cannot."

    Umm... when you say "theorem A shows B" it means that theorem A proves B. Not that it's "reasonable to conclude". It is "reasonable to conclude" just about anything from just about anything - because "reasonable" is a subjective term.
  • Re:comparisons (Score:5, Informative)

    by MarkusQ ( 450076 ) on Thursday June 30, 2005 @01:23AM (#12948138) Journal

    But a computer cannot demonstrate this truth. I don't claim to understand why not, but it clearly says in the wikipedia article that it can't.

    Short answer: you're incorrect.

    Long answer: The reason you seem to think that you are correct is also, I believe, incorrect. Godel's proof basically involves forming the statement "this statement is false" in a specialized language that allows you to do so without reference to pronouns--instead, he assigned each symbol a unique integer, and worked out ways of manipulating them both with and without regard to their "meaning". That part would be easy to do with a computer (e.g. asci/text editor/compiler).

    Next, he posited a string of symbols where the meaning was related to the process for the manipulation of the meaningless symbols (this is also easy on a computer--sort of like using an editor to edit its own source code).

    Using these, he constructed a relatively normal argument about the meaning level that coresponded to an argument at the symbol level--an argument that said "the argument represented by this long string of digits is unprovable"--but the kicker was the long string of digits was the coded representation of the argument itself. If false, the system could obviously not prove it (since we are assuming here that it only proves things that are true). Therefore it must be true, but that means it can't be proven within the system. Tricky, but there was nothing magical about the logic--no quantum mechanical must-derive-this-step-from-the-sprit-world voodoo that would make it impossible for a computer to follow.

    --MarkusQ

    P.S. A computer might not be able to understand the proof, but that shouldn't be held against it--after all, most of the people who discuss it don't understand it either.

  • by tgv ( 254536 ) on Thursday June 30, 2005 @03:07AM (#12948480) Journal
    First of all, I happen to be doing computational modelling of psycholinguistic processes, and I know (some of) Spivey's work.

    The claims that are made in the article do not contradict the idea of continuous attraction, but they do not prove it either. There is a much simpler explanatation, which is hinted at near the end of the article: one or more processes that try to solve the problem using competition. As a matter of fact, this study simply provides a little bit more evidence of what has been en vogue for a long time.

    This behaviour *can* be mimicked quite easily using digital computers, and is definitely not shown by all biological processes.

    So, our minds don't work like digital computers in the sense that they cannot store and delete information in the same way. That's been known for a long time, and this experiment doesn't prove it.

    Some of the basic cognitive processes can be modelled on a computer, though, but that's not surprising either, since computers are supposed to be able to compute "everything computable" and there is still no reason to assume that the workings of our brain cannot be approached by a computational model.

    So, nothing to see, only of interest to psycholinguistic experts. Move on, please.
  • Re:comparisons (Score:2, Informative)

    by stymyx ( 862298 ) on Thursday June 30, 2005 @04:24AM (#12948668)
    No. In fact, a non-deterministic Turing machine is exactly equivalent in computational power to a deterministic one.
  • Re:comparisons (Score:3, Informative)

    by orthogonal ( 588627 ) on Thursday June 30, 2005 @07:59AM (#12949143) Journal
    Just from the linked article, I'm not sure that I buy the premise.*

    HOWEVER, it appears the parent poster is one of the three authors of the paper under discussion, so somebody ought to mod the parent post up as "Informative".

    *(Just for a start, the article quotes the researcher as saying,
    "In thinking of cognition as working as a biological organism does, on the other hand, you do not have to be in one state or another like a computer, but can have values in between -- you can be partially in one state and another, and then eventually gravitate to a unique interpretation, as in finally recognizing a spoken word," Spivey said.
    But a computer can and routinely does represent multiple or partial states.

    A multiple state representation: const ONE_STATE = 0x1; const ANOTHER_STATE = 0x2 ; int currentState = ONE_STATE | ANOTHER_STATE ; while( dataSupportsEitherState() ) getAdditionalData() ;

    A partial state, or a "value in between": double quantity = 0.5 ;

    (A purist will point out that multiple or partial states are implemented as additional states; but it's the interpretation, not the implementation, that matters.))
  • Re:Misleading (Score:3, Informative)

    by mikael ( 484 ) on Thursday June 30, 2005 @08:44AM (#12949304)
    From research carried out on retinal cells, it the time between pulse (depolarization/repolarization of the synapse) that conveys the most information - stronger stimulation => more frequent pulses.

    And there is a minimum time between such pulses. For a higher response rate/precision, more cells are used.

    A single neuron will take in inputs from up to as many as 10,000 other neurons, with a threshold that has to be exceeded before it will fire itself. And each inputs can have the effect of increasing or decreasing the chances of firing.
    There's some debate as to whether an individual neuron implements basic logic operations or whether it's a weighted sum calculation.

  • Re:Yes they do (Score:2, Informative)

    by mjspivey ( 896286 ) on Thursday June 30, 2005 @10:00AM (#12949773)
    Some examples of people who continue to argue for sequential processing and/or discrete representation and/or modular cognitive architectures are Jerry Fodor, Zenon Pylyshyn, and Eric Dietrich (Philosophy of Mind), John Anderson and Art Markman (Cognitive Psychology), Doug Lenat (Artificial Intelligence), Steven Pinker and Elizabeth Spelke (Developmental Psychology), Leda Cosmides and Nancy Kanwisher (Cognitive Neuroscience)... the list goes on.

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