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Oh dear. This isn’t my field at all, and maybe I’m just doing a bad job of understanding their point, but this sounds completely bogus. Really...the brain does

by baddox 8y ago

Oh dear. This isn’t my field at all, and maybe I’m just doing a bad job of understanding their point, but this sounds completely bogus. Really...the brain doesn’t create representations of visual stimuli or store memories? Under what possible definitions of those words can this statement be sensical? Surely the author believes that visual stimuli cause measurable changes in brain state, and that people can indeed remember past visual stimuli. Then how is it true that brains don’t create representations of visual stimuli and store and retrieve them? I’m at a loss here. Perhaps the author means that the brain doesn’t do these things in the same way as digital electronic computers we’re familiar with. That’s certainly the case at the most basic level.

lisper 8y ago
> this sounds completely bogus It is. http://blog.rongarret.info/2019/01/are-you-turing-machine.html http://blog.rongarret.info/2019/01/are-you-turing-machine.ht...
skywhopper 8y ago
Yes “computer” here means “digital electronic computer” and yes the storage, retrieval, and processing all happens very differently in the brain than digital computers are capable of. You may think these are dumb points for the author to make, but it’s not clear to me at all that the media or the VCs who buy the hype about machine learning, AI, and self-driving cars realize just how different they are.
- naasking 8y ago
  > Yes “computer” here means “digital electronic computer” and yes the storage, retrieval, and processing all happens very differently in the brain than digital computers are capable of. No, it's incorrect to use "digital computer" here. More correct might be a von Neumann architecture computer. But then that shows that the author is attacking a strawman: people comparing brains to computers aren't limiting themselves to such an architecture.
  - ChrisSD 8y ago
    Are you sure? This mostly comes up in pop sci explanations where von Neumann architecture may as well be synonymous with "digital computer" because it's all the vast majority of readers are familiar with.
    - naasking 8y ago
      A "digital computer" is simply one in which information is represented in binary. The encoding of information does not alter the process of computation, so that's an irrelevant detail to compare to. We have plenty of Harvard architecture computers (eg. DSPs), and there are plenty of other computational architectures (DNA computing, optical computing, quantum computing).
      - ChrisSD 8y ago
        Sure but my point is they aren't what people think about when you say "digital computer" or use that as an analogy. People think about what they are familiar with in their every day lives.
        naasking 8y ago
        I don't see how that's relevant. The article is attacking the claim "the brain is a computer". That means all computers. The fact that the article's example were of a specific type of computer architecture, and had nothing specific to do with digital computers per se despite the article claiming it does, just proves my point that the argument is flawed.
        ChrisSD 8y ago
        Because it's about people's mental models. When you use an analogy ("like a digital computer") to examine another phenomena than of course people will interpret that in terms they are familiar with. Otherwise what's the point in using an analogy?
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TheOtherHobbes 8y ago
I'm not sure I understand the piece either, but I think it's trying to say that human memories are associative, sequential, and distributed rather than localised. So there isn't "a representation" in the discrete sense. It's more like the entire system changes, and it's impossible to physically scan specific elements of it to retrieve selected content. You can trigger selective recall, but you're triggering a complex and noisy process which generates an experience that may include remembered elements - not pulling out a predictable bit pattern. There isn't an exact equivalent in CS. Traditional binary memory is obviously nothing like human memory. Neural nets have some superficial similarities, but they lack generality. I'm not completely convinced by the argument, but I'm glad someone is making it. The problem with it is that we can remember specific discrete facts quite easily. If you ask me how many flats the key of F major has, I can tell you without being distracted by other memories. What we don't know is how that fact is represented, how exactly my brain changed after I learned it, how similar those changes would be to changes in other brains learning the same fact, whether everyone has similar subjective experiences on recall, or how to scan someone's brain to check whether or not the fact is known.
- behringer 8y ago
  I think researchers are working on this very thing, and it seems like the brain does store "visual representations" or at least it can't be ruled out at this point. https://www.theregister.co.uk/2013/08/20/mindreading_mri_spots_letters_in_the_brain/ https://www.theregister.co.uk/2013/08/20/mindreading_mri_spo... And of course, why wouldn't the brain store a visual representation of what you remembered. That would be the easiest way to store and retrieve it, which is why we do that on computers as well.
  - slowmovintarget 8y ago
    > Why wouldn't the brain... Because it isn't how brains work. Recollection is re-experience. The article you link says researchers taught a model how to match patterns to letters, given the presumption that they are letters, for a single subject's MRIs taken while they were experiencing the sight of words and letters. Not at all the same as saying a brain stores data.
barberousse 8y ago
>Surely the author believes that visual stimuli cause measurable changes in brain state They repeat throughout that it does > and that people can indeed remember past visual stimuli. They agree also >Then how is it true that brains don’t create representations of visual stimuli and store and retrieve them? >Perhaps the author means that the brain doesn’t do these things in the same way as digital electronic computers we’re familiar The author is definitely in agreement with the second statement from what I understand. However, I think where people are getting lost is that they expect the author to resolve definitions for "cognitive"/information processing terms (because in our day and age, they are identical) when actually the author is rhetorically refusing them validity, and on purpose. Hence why in those places where the author is expected to supply an equivalently robust counter-definition they instead pose a far more general definition, such as, with respect to learning, "the brain changes". The name for this rhetorical strategy is "refusing the blackmail of the Enlightenment".
bkdbkd 8y ago
Totally with you here. Not a neuroscientist. But I am a computer scientist. Lots of strong opinions, not a lot of strong facts. The analogies are interesting but they break down quick. "We don't create representations of visual stimuli"..."We don't retrieve information or images or word from memory registers" Neither do computers in many cases. It's as if the author is saying because in the brain isn't a tape recorder or film camera then it doesn't work like a computer. Nope. Studies show that much like a computer we encode information as we store it. Because we encode it fancy ( or weird :-) doesn't mean its not encoded or retrieved. The Dollar Bill example is a red herring. Just ppitballing here: What if, instead of creating an image for the dollar, the subject's mind created a visual'thumbnail' and 'hash' of the real dollar. The thumbnail she can recall easily and lets her draw 'enough' of the bill to be vaguely recognizable. The hash, lets her recognize the real deal whenever she sees it. She simply compares the hash of this new object with list of hashes, and if its a dollar the mind finds a match. Of course, it far more sophisticated, but these simple methods, cleanly account for what the author observed.

by baddox 8y ago

lisper 8y ago

> this sounds completely bogus It is. http://blog.rongarret.info/2019/01/are-you-turing-machine.html http://blog.rongarret.info/2019/01/are-you-turing-machine.ht...

skywhopper 8y ago

Yes “computer” here means “digital electronic computer” and yes the storage, retrieval, and processing all happens very differently in the brain than digital computers are capable of. You may think these are dumb points for the author to make, but it’s not clear to me at all that the media or the VCs who buy the hype about machine learning, AI, and self-driving cars realize just how different they are.

naasking 8y ago
> Yes “computer” here means “digital electronic computer” and yes the storage, retrieval, and processing all happens very differently in the brain than digital computers are capable of. No, it's incorrect to use "digital computer" here. More correct might be a von Neumann architecture computer. But then that shows that the author is attacking a strawman: people comparing brains to computers aren't limiting themselves to such an architecture.
- ChrisSD 8y ago
  Are you sure? This mostly comes up in pop sci explanations where von Neumann architecture may as well be synonymous with "digital computer" because it's all the vast majority of readers are familiar with.
  - naasking 8y ago
    A "digital computer" is simply one in which information is represented in binary. The encoding of information does not alter the process of computation, so that's an irrelevant detail to compare to. We have plenty of Harvard architecture computers (eg. DSPs), and there are plenty of other computational architectures (DNA computing, optical computing, quantum computing).
    - ChrisSD 8y ago
      Sure but my point is they aren't what people think about when you say "digital computer" or use that as an analogy. People think about what they are familiar with in their every day lives.
      - naasking 8y ago
        I don't see how that's relevant. The article is attacking the claim "the brain is a computer". That means all computers. The fact that the article's example were of a specific type of computer architecture, and had nothing specific to do with digital computers per se despite the article claiming it does, just proves my point that the argument is flawed.
        ChrisSD 8y ago
        Because it's about people's mental models. When you use an analogy ("like a digital computer") to examine another phenomena than of course people will interpret that in terms they are familiar with. Otherwise what's the point in using an analogy?

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TheOtherHobbes 8y ago

I'm not sure I understand the piece either, but I think it's trying to say that human memories are associative, sequential, and distributed rather than localised. So there isn't "a representation" in the discrete sense. It's more like the entire system changes, and it's impossible to physically scan specific elements of it to retrieve selected content. You can trigger selective recall, but you're triggering a complex and noisy process which generates an experience that may include remembered elements - not pulling out a predictable bit pattern. There isn't an exact equivalent in CS. Traditional binary memory is obviously nothing like human memory. Neural nets have some superficial similarities, but they lack generality. I'm not completely convinced by the argument, but I'm glad someone is making it. The problem with it is that we can remember specific discrete facts quite easily. If you ask me how many flats the key of F major has, I can tell you without being distracted by other memories. What we don't know is how that fact is represented, how exactly my brain changed after I learned it, how similar those changes would be to changes in other brains learning the same fact, whether everyone has similar subjective experiences on recall, or how to scan someone's brain to check whether or not the fact is known.

behringer 8y ago
I think researchers are working on this very thing, and it seems like the brain does store "visual representations" or at least it can't be ruled out at this point. https://www.theregister.co.uk/2013/08/20/mindreading_mri_spots_letters_in_the_brain/ https://www.theregister.co.uk/2013/08/20/mindreading_mri_spo... And of course, why wouldn't the brain store a visual representation of what you remembered. That would be the easiest way to store and retrieve it, which is why we do that on computers as well.
- slowmovintarget 8y ago
  > Why wouldn't the brain... Because it isn't how brains work. Recollection is re-experience. The article you link says researchers taught a model how to match patterns to letters, given the presumption that they are letters, for a single subject's MRIs taken while they were experiencing the sight of words and letters. Not at all the same as saying a brain stores data.

barberousse 8y ago

>Surely the author believes that visual stimuli cause measurable changes in brain state They repeat throughout that it does > and that people can indeed remember past visual stimuli. They agree also >Then how is it true that brains don’t create representations of visual stimuli and store and retrieve them? >Perhaps the author means that the brain doesn’t do these things in the same way as digital electronic computers we’re familiar The author is definitely in agreement with the second statement from what I understand. However, I think where people are getting lost is that they expect the author to resolve definitions for "cognitive"/information processing terms (because in our day and age, they are identical) when actually the author is rhetorically refusing them validity, and on purpose. Hence why in those places where the author is expected to supply an equivalently robust counter-definition they instead pose a far more general definition, such as, with respect to learning, "the brain changes". The name for this rhetorical strategy is "refusing the blackmail of the Enlightenment".

bkdbkd 8y ago

Totally with you here. Not a neuroscientist. But I am a computer scientist. Lots of strong opinions, not a lot of strong facts. The analogies are interesting but they break down quick. "We don't create representations of visual stimuli"..."We don't retrieve information or images or word from memory registers" Neither do computers in many cases. It's as if the author is saying because in the brain isn't a tape recorder or film camera then it doesn't work like a computer. Nope. Studies show that much like a computer we encode information as we store it. Because we encode it fancy ( or weird :-) doesn't mean its not encoded or retrieved. The Dollar Bill example is a red herring. Just ppitballing here: What if, instead of creating an image for the dollar, the subject's mind created a visual'thumbnail' and 'hash' of the real dollar. The thumbnail she can recall easily and lets her draw 'enough' of the bill to be vaguely recognizable. The hash, lets her recognize the real deal whenever she sees it. She simply compares the hash of this new object with list of hashes, and if its a dollar the mind finds a match. Of course, it far more sophisticated, but these simple methods, cleanly account for what the author observed.