7 ms·

Cracking the Brain’s Codes

sj4nz 12y ago
There is probably not going to be any singular common code for all brains, this is pattern recognition in a fatty sponge that grew from a single cell. There will be families of similar neural networks in roughly the same locations according to where the input/outputs are. My best intuition is for some people who have "savant"-like powers are they were fortunate to grow exceptionally useful networks for their needs. If you're a bio-hacker with a penchant for hardware upgrades, I think that you don't need to wait for anyone to discover "the encoding" to install an interface to your mind. Just do it, and like everything else in your brain, you'll spend a few weeks training your mind to use the new sense and digital motor skills. Bio-feedback technology is already here.
- negativity 12y ago
  I pretty much agree with this sentiment. They point out that information seems to directly correlate with synaptic structures, so if that's true then it's pretty doubtful that we'd be able to come up with a codified syntax for the definition of memories, and then readily implement the syntax upon a living creatire in a healthy (and cost-effective/legal) way, at least insofar as directly enforcing synaptic structures known to provoke the recall of memories. Meanwhile, preparing experiments for creatures not yet alive is an altogether different game. Growing a structure, by controlling chemical pathways, or physically restricting the movement of neurons trained or genetically modified to fire according to pre-defined external stimuli seems to be what the article is driving at. But what good will that do me, if I'm already alive? Maybe a tiny lobotomy for me, and then drop in a blob vat grown cells, that brain slug their way into place? Would I still be me after that?
  - sj4nz 12y ago
    That would be a pretty macabre experiment. But I would guess that you would still be you, but with the after effects of a stroke. The larger the volume of the cut, the larger the damage. That would be the a form of brain transfusion---an installation of living blank media. I am unsure of how you would mentally direct the brain to use the new resource.
    - negativity 12y ago
      Well, ideally, the "new resource" is also genetically matched living brain, and given the plasticity of brain tissue, and maybe by way of a novel as-yet-uninvented means of coaxing, the two would mutually recognize the severed gap between the two pieces, and heal back together. I mean I'm not a brain surgeon, so I'm operating with possibly a great deal of very wrong assumptions about how the brain recovers and heals from lacerations. Would it be like trying to mend a spinal cord injury, which we still haven't quite mastered? Or since it would be surgery, would the brain take to it like rejoined pieces of healthy brain tissue, after the removal of a malignant tumor? I suppose a lot of that would depend on the quality of the custom grown tissue, and the technique of the operation. Either way, nerve cells are essentially highly specialized finicky amoeba, with dendrites acting as elaborately decorated pseudopods. They don't quite "swim" like white blood cells, but sort of creep along, and test each other out, delicately and selectively. And apparantly human cells can specialize to the point where a single cell can recognize key concepts of individualized external human identities (the article mentions Jennifer Aniston and Luke Skywalker). So, in the sense that dendrites are pseudopods, and pseudopods are, along their external surface, celluar membranes (lipid bi-layers, decorated with embedded proteins), the proteins are the specialized structures that ultimately drive the behavior of the cell to direct it's psuedopods this way or that way. It's a mixture of chemical reactions all the way down, even if there is a layer of very fundamental electrical processes mixed in, due to the deliberately maintained PH value, and shifting electrolytic potential of the chemicals involved. There was an article describing brain behavior as analogous to a swarm of ants. This makes sense, since ant communities guide their collective behavior by tagging their territories with scent, which gets reinforced with increased ants marching along pathways. So, at the end of the day, some kind of transplant process would probably require an arm of research tackling the micro-scale and nano-scale structures and living behavior of the tissue, but also the chemical aspects of how neurons sniff each other out, and decide to stimulate each other through the electric polarity fluctuations of their electrolyte juices.
closetnerd 12y ago
If you wan't a good intuitive understanding of the neocortex then I seriously suggest reading up on Sparse Distributed Representations. A theory refined by Gerard Rinkus and Jeff Hawkins.
- sj4nz 12y ago
  Is this akin to Kurzweil's [Pattern Recognition Theory of Mind][0] that estimates about 300 million pattern recognizers in the brain? [0]: https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_Recognition_Theory_of_Mind https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_R...
  - closetnerd 12y ago
    Honestly, for me at least, the ideas that Kurzweil puts forwards are repetitive of the same things Hawkins discusses in his book [On Intelligence][0]. Sparse Distributed Representations are a newer idea that Kurzweil hasn't yet discussed. Actually there was a Google Talk that Hawkins gave about Sparse Distributed Representations and Kurzweil was present. [0]: http://en.wikipedia.org/wiki/On_Intelligence http://en.wikipedia.org/wiki/On_Intelligence
    - sj4nz 12y ago
      For anyone else following along there is the [Sparse Distributed Representations][0] write-up at Numenta's GitHub. [0]: https://github.com/numenta/nupic/wiki/Sparse-Distributed-Representations https://github.com/numenta/nupic/wiki/Sparse-Distributed-Rep...
ivan_ah 12y ago
> What matters most is not precisely when a particular neuron spikes but how often it does; the rate of firing is the main currency. I'm not too sure about that. My gut feeling is that at least half of the information in the brain is encoded in the exact timing of the spikes. In a model that takes time into account, certain neurons function as a "coincidence detector" sensitive to certain events. e.g. your brain deduces which direction a sound is coming from by analyzing the delay difference for the sound input from each ear to arrive to the brain. Specifically, sound-orientation detector neurons read from neurons of different lengths to each ear. You know the sound is coming from front-and-left if the coincidence-detector neuron that has a short lead to the left ear and a long lead to the right ear fires.
- joeyo 12y ago
  There are clear examples where spike timing matters a great deal and the Jeffres model of sound localization, as you point out, is a great example of this. However, spike timing codes seem to be more prevalent in the periphery; rate codes dominate in central structures, and in particular the cortex. The receptors of sensory afferents faithfully report the timing of individual events (of photons, pinpricks of the skin, etc) with single spikes. But after a few synapses the pattern of spikes looks much more like a (noisy) rate code. The origin of the noise, whether it even is noise, how the temporal code is transformed into a rate code, and many other questions along these lines are active research topics. All that aside, Koch is well aware that there is evidence for both rate and temporal codes. As he wrote, "spikes mean different things in different contexts."
collyw 12y ago
Starts with the assumption that brain / brain activity = conscious self. I am not aware of any evidence that this is the case. (That is not to say that I think the two are unrelated, I just think this assumption ought to be challenged, rather than taken for granted).
- macspoofing 12y ago
  >Starts with the assumption that brain / brain activity = conscious self. It's not assumption that there is nothing more to the mind than the material brain. This is based on very strong empirical evidence. We have about 100 years worth of Neuroscience. We also have fundamental physics and laws of chemistry. There is no reason or evidence to believe that something magical is happening in the brain, or that somehow particles which behave according to the laws of physics outside of the brain, somehow don't, when part of the brain. We have a very good understanding of all the fundamental forces that govern the physics of our everyday experience. > I just think this assumption ought to be challenged, rather than taken for granted Challenge it then. What is your reason to believe the laws of physics are broken in the brain or that the mind is more than the material brain? Is there even one shred of evidence for that?
  - aethertap 12y ago
    I would just add that the mind probably is partially an outgrowth of the entire connected body system rather than just the brain in isolation. The feedbacks between the hormonal system, parasympathetic/sympathetic nervous system, and various other influences in the body have definite effects on the function of the mind, assuming that mind encompasses behavior. There's a fascinating course on this topic available from The Great Courses: http://www.thegreatcourses.com/tgc/courses/course_detail.aspx?cid=1597 http://www.thegreatcourses.com/tgc/courses/course_detail.asp...
    - macspoofing 12y ago
      That's an interesting theory. I could see how that could, in principle, be true. There's no reason why the neurons that make up our nervous system wouldn't play a part in creating the mind.
tokenadult 12y ago
I liked this article after reading it. Before I read it, I thought it would be yet another Technology Review article by a staff writer, a superficial look at unreplicated research, but I find as I reach the end of the article that the two co-authors are both leading researchers on the topic and the second co-author is Gary Marcus, a psychology professor who is a diligent author of popular books about psychology to explain the latest findings from neuroscience-based psychology to the public. This is worth a read. It's not the last word on the subject, as the title alone should make clear, but it's a good introduction to the current research program and the complications it is discovering as scientists seek to develop a deeper understanding of the function of the human brain.

sj4nz 12y ago

There is probably not going to be any singular common code for all brains, this is pattern recognition in a fatty sponge that grew from a single cell. There will be families of similar neural networks in roughly the same locations according to where the input/outputs are. My best intuition is for some people who have "savant"-like powers are they were fortunate to grow exceptionally useful networks for their needs. If you're a bio-hacker with a penchant for hardware upgrades, I think that you don't need to wait for anyone to discover "the encoding" to install an interface to your mind. Just do it, and like everything else in your brain, you'll spend a few weeks training your mind to use the new sense and digital motor skills. Bio-feedback technology is already here.

negativity 12y ago
I pretty much agree with this sentiment. They point out that information seems to directly correlate with synaptic structures, so if that's true then it's pretty doubtful that we'd be able to come up with a codified syntax for the definition of memories, and then readily implement the syntax upon a living creatire in a healthy (and cost-effective/legal) way, at least insofar as directly enforcing synaptic structures known to provoke the recall of memories. Meanwhile, preparing experiments for creatures not yet alive is an altogether different game. Growing a structure, by controlling chemical pathways, or physically restricting the movement of neurons trained or genetically modified to fire according to pre-defined external stimuli seems to be what the article is driving at. But what good will that do me, if I'm already alive? Maybe a tiny lobotomy for me, and then drop in a blob vat grown cells, that brain slug their way into place? Would I still be me after that?
- sj4nz 12y ago
  That would be a pretty macabre experiment. But I would guess that you would still be you, but with the after effects of a stroke. The larger the volume of the cut, the larger the damage. That would be the a form of brain transfusion---an installation of living blank media. I am unsure of how you would mentally direct the brain to use the new resource.
  - negativity 12y ago
    Well, ideally, the "new resource" is also genetically matched living brain, and given the plasticity of brain tissue, and maybe by way of a novel as-yet-uninvented means of coaxing, the two would mutually recognize the severed gap between the two pieces, and heal back together. I mean I'm not a brain surgeon, so I'm operating with possibly a great deal of very wrong assumptions about how the brain recovers and heals from lacerations. Would it be like trying to mend a spinal cord injury, which we still haven't quite mastered? Or since it would be surgery, would the brain take to it like rejoined pieces of healthy brain tissue, after the removal of a malignant tumor? I suppose a lot of that would depend on the quality of the custom grown tissue, and the technique of the operation. Either way, nerve cells are essentially highly specialized finicky amoeba, with dendrites acting as elaborately decorated pseudopods. They don't quite "swim" like white blood cells, but sort of creep along, and test each other out, delicately and selectively. And apparantly human cells can specialize to the point where a single cell can recognize key concepts of individualized external human identities (the article mentions Jennifer Aniston and Luke Skywalker). So, in the sense that dendrites are pseudopods, and pseudopods are, along their external surface, celluar membranes (lipid bi-layers, decorated with embedded proteins), the proteins are the specialized structures that ultimately drive the behavior of the cell to direct it's psuedopods this way or that way. It's a mixture of chemical reactions all the way down, even if there is a layer of very fundamental electrical processes mixed in, due to the deliberately maintained PH value, and shifting electrolytic potential of the chemicals involved. There was an article describing brain behavior as analogous to a swarm of ants. This makes sense, since ant communities guide their collective behavior by tagging their territories with scent, which gets reinforced with increased ants marching along pathways. So, at the end of the day, some kind of transplant process would probably require an arm of research tackling the micro-scale and nano-scale structures and living behavior of the tissue, but also the chemical aspects of how neurons sniff each other out, and decide to stimulate each other through the electric polarity fluctuations of their electrolyte juices.

closetnerd 12y ago

If you wan't a good intuitive understanding of the neocortex then I seriously suggest reading up on Sparse Distributed Representations. A theory refined by Gerard Rinkus and Jeff Hawkins.

sj4nz 12y ago
Is this akin to Kurzweil's [Pattern Recognition Theory of Mind][0] that estimates about 300 million pattern recognizers in the brain? [0]: https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_Recognition_Theory_of_Mind https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_R...
- closetnerd 12y ago
  Honestly, for me at least, the ideas that Kurzweil puts forwards are repetitive of the same things Hawkins discusses in his book [On Intelligence][0]. Sparse Distributed Representations are a newer idea that Kurzweil hasn't yet discussed. Actually there was a Google Talk that Hawkins gave about Sparse Distributed Representations and Kurzweil was present. [0]: http://en.wikipedia.org/wiki/On_Intelligence http://en.wikipedia.org/wiki/On_Intelligence
  - sj4nz 12y ago
    For anyone else following along there is the [Sparse Distributed Representations][0] write-up at Numenta's GitHub. [0]: https://github.com/numenta/nupic/wiki/Sparse-Distributed-Representations https://github.com/numenta/nupic/wiki/Sparse-Distributed-Rep...

ivan_ah 12y ago

> What matters most is not precisely when a particular neuron spikes but how often it does; the rate of firing is the main currency. I'm not too sure about that. My gut feeling is that at least half of the information in the brain is encoded in the exact timing of the spikes. In a model that takes time into account, certain neurons function as a "coincidence detector" sensitive to certain events. e.g. your brain deduces which direction a sound is coming from by analyzing the delay difference for the sound input from each ear to arrive to the brain. Specifically, sound-orientation detector neurons read from neurons of different lengths to each ear. You know the sound is coming from front-and-left if the coincidence-detector neuron that has a short lead to the left ear and a long lead to the right ear fires.

joeyo 12y ago
There are clear examples where spike timing matters a great deal and the Jeffres model of sound localization, as you point out, is a great example of this. However, spike timing codes seem to be more prevalent in the periphery; rate codes dominate in central structures, and in particular the cortex. The receptors of sensory afferents faithfully report the timing of individual events (of photons, pinpricks of the skin, etc) with single spikes. But after a few synapses the pattern of spikes looks much more like a (noisy) rate code. The origin of the noise, whether it even is noise, how the temporal code is transformed into a rate code, and many other questions along these lines are active research topics. All that aside, Koch is well aware that there is evidence for both rate and temporal codes. As he wrote, "spikes mean different things in different contexts."

collyw 12y ago

Starts with the assumption that brain / brain activity = conscious self. I am not aware of any evidence that this is the case. (That is not to say that I think the two are unrelated, I just think this assumption ought to be challenged, rather than taken for granted).

macspoofing 12y ago
>Starts with the assumption that brain / brain activity = conscious self. It's not assumption that there is nothing more to the mind than the material brain. This is based on very strong empirical evidence. We have about 100 years worth of Neuroscience. We also have fundamental physics and laws of chemistry. There is no reason or evidence to believe that something magical is happening in the brain, or that somehow particles which behave according to the laws of physics outside of the brain, somehow don't, when part of the brain. We have a very good understanding of all the fundamental forces that govern the physics of our everyday experience. > I just think this assumption ought to be challenged, rather than taken for granted Challenge it then. What is your reason to believe the laws of physics are broken in the brain or that the mind is more than the material brain? Is there even one shred of evidence for that?
- aethertap 12y ago
  I would just add that the mind probably is partially an outgrowth of the entire connected body system rather than just the brain in isolation. The feedbacks between the hormonal system, parasympathetic/sympathetic nervous system, and various other influences in the body have definite effects on the function of the mind, assuming that mind encompasses behavior. There's a fascinating course on this topic available from The Great Courses: http://www.thegreatcourses.com/tgc/courses/course_detail.aspx?cid=1597 http://www.thegreatcourses.com/tgc/courses/course_detail.asp...
  - macspoofing 12y ago
    That's an interesting theory. I could see how that could, in principle, be true. There's no reason why the neurons that make up our nervous system wouldn't play a part in creating the mind.

tokenadult 12y ago

I liked this article after reading it. Before I read it, I thought it would be yet another Technology Review article by a staff writer, a superficial look at unreplicated research, but I find as I reach the end of the article that the two co-authors are both leading researchers on the topic and the second co-author is Gary Marcus, a psychology professor who is a diligent author of popular books about psychology to explain the latest findings from neuroscience-based psychology to the public. This is worth a read. It's not the last word on the subject, as the title alone should make clear, but it's a good introduction to the current research program and the complications it is discovering as scientists seek to develop a deeper understanding of the function of the human brain.