8 ms·

Does one simple rule underlie learning in the brain?

90 points by ofou 4y ago

teledyn 4y ago
There is the Theory of Everything and we're nearly certain it exists, we're really really close, we can smell it. Until then, we have two not so simple almost rules, quantum chromo-du-jour and pesky relativity. That's just my opinion of course. Who knows, it could be cymatic patterns carving analog ai onto the nerve cell surface, or a schoolmaster with a wooden pointer.
- dwd 4y ago
  Or the universe as we perceive it is a fabrication of our time-bound perception and any "Theory of Everything" is bound to fall short as reality is beyond our human perception. I would be interested to see where experiments with time crystals take us as they could be a key to discovering the true nature of reality not bound by time.
personjerry 4y ago
Can someone explain this in English?
- tgv 4y ago
  The title is clickbait. They've found something that seems to be true for all synapses (even though the article is too vague to make that out, and it only seems to be valid for pyramidal cells; these are important though), and it's about some aspect of plasticity: synaptic change can be predicted from calcium levels. This is not a learning rule, but a small part of the learning process. It also seems to offer a new direction in learning research, namely the influence of one synaptic change on other synapses. So it's interesting, but at a very technical level.
dwd 4y ago
Interested to see how this fits with Hawkin's 1000 Brain theory which was focused on cortical columns as modelling units. This seems to step down a level to individual voting elements.
- HarHarVeryFunny 4y ago
  Well, step down a few levels, if you want to put it that way. This model describes how connections between individual neurons (real physical cells, not abstract "voting units") work. Inter-neuron connections (aka synapses) are the basis of long term memories/learning. The human cortex is a thin sheet (scrunched up in our head) that would stretch out to about the size of a tea towel, that has 6 layers of neurons, with a specific inter-layer connect pattern. A cortical column is what you'd get if you took a cookie cutter and cut a small cylindrical section, like a cookie, through the cortical sheet. It'll have those 6 layers of neurons, but maybe 100 neurons total (not 6) depending on what size cookie/column you're talking about. Any model of the brain (cortex) based on cortical columns is going to be a high level functional model of that mostly abstracts away what the individual neurons are doing. At this level of abstraction, you don't really care about the detailed behavior of individual neurons, since you're assuming that their aggregate behavior can adequately be described by your higher level model.
  - stefantalpalaru 4y ago
sgt101 4y ago
The title is very broad and with it's postulate hints at a massive overclaim, but this paper seems to explain something significant and interesting about how synapses work. None of which generalizes to "the brain" or "learning" really.
usgroup 4y ago
"What underlies learning in the brain might be actually simpler than previously thought despite the brain being one of the most complex objects in the known universe. A collaboration of Scientists led by the EPFL Blue Brain Project has achieved a major advance in accurately simulating the synaptic changes thought to implement learning in the neocortex, opening the door to greater understanding of learning in the brain."
mjburgess 4y ago
Does one simple rule underlie the climate? Biological systems are complex and chaotic. Denying this so that "any old model will do" is pseudoscience; and we should start calling this out.
- zasdffaa 4y ago
  > Biological systems are ... chaotic Are they? Seems they are extraordinarily stable. Tortoises can last two centuries, that's not the signature of chaos. What do you mean by that word?
  - hprotagonist 4y ago
    A good definition of chaos that certainly applies to biological systems: Chaos: When the present determines the future, but the approximate present does not approximately determine the future. Lorenz
    - zasdffaa 4y ago
      A dead tortoise is 100% going to be dead tomorrow. A tortoise alive now is 99.995% likely to be alive tomorrow, if external threats are removed. Pretty sure that is not the behaviour of chaos under your definition.
      - hprotagonist 4y ago
        “is this neuron going to spike and if it does can we say why” is, though. “if external threats are removed” is an attempt to linearize, and therefore remove chaotic behavior. Sometimes you can pull this off and have a reasonable model at the end; sometimes you cannot. This tells you more about your model than it does about the system you’re studying.
        zasdffaa 4y ago
        Name me a stable system that does not become destroyed when an overwhelming amount of energy is applied to it. Is a tortoise with a stick of dynamite attached on a random timer chaotic or not? Seems yes. So what are the limits that define chaos? By that you could say all is chaotic. We lack a suitable definition here.
tremon 4y ago
a flexible framework for studying cortical learning algorithms in silico What does this refer to? Are they talking about (mechanical) simulation of a brain model in a computer program, biological experimentation with chemical processes on a silicon substrate, or about translating these findings to current machine learning systems?
- hocuspocus 4y ago
  > simulation of a brain model in a computer program That one.
iandanforth 4y ago
TLDR; There are lots of types of neurotransmitters and lots of types of neurons, even within the general class of Pyramidal neurons. There seem to be large variations in how and when the types of neurons form and modify synapses (connections) between them. What if there were only a few factors that govern most of that variation? Using computer simulation the authors focus on calcium as a signaling mechanism, the size of synaptic spines, and known behavior of pre and post synaptic structures to create a predictive model of how and when synapses will be modified. They then compare their simulated results and model with results taken from real-world experiments and get good agreement.
- achr2 4y ago
  Thanks. I think this summary helps clarify the statement in the title.
jl6 4y ago
Kind of off topic from the article, but here’s another scenario to add to the AI Risk conversation: Sentience (along with consciousness, sapience, and qualia) turns out to be undefinable woo, leading to a declaration that AI is not sentient and neither are humans, and so rather than treating machines like people, we end up treating people like machines. Yeah, yeah, we already do treat people like machines etc. etc., but we risk further dehumanization if we decide the human mind is nothing special after all.
- telmo 4y ago
  I find that the term "woo" suffered a semantic drift in the last few decades. It used to refer to things that pretend to be scientific by using the terminology and aesthetics of science without being grounded in real empiricism. One classical example of "real woo" is homeopathy. Nowadays, "woo" is being applied to anything that science cannot model or explain. Science cannot explain consciousness? Well it must be woo then! You tell me that you experience your own consciousness, and that you are sure it exists? No, it's an illusion my poor child. An illusion of whom, you ask? That is starting to sound like philosophy, which is not science so it must be woo. Careful. Woo is becoming synonymous with "heretic" and "science" no longer means what I thought it meant. In my view, the defining aspects of science, the ones that make it such a splendorous endeavor, are modesty and doubt. All scientific theories are under the permanent risk of being falsified, otherwise they are not serious theories. There are many things we do not understand, and it might even be that this will always be the case. Some things defy our current understanding or reality, and consciousness is one of them. That doesn't make it woo, and those that pretend that it does are like the fearful religious people of previous ages, as they shout "woo"/"heretic" at those who have the temerity of harboring doubts and questions.
Georgelemental 4y ago
Betteridge's law of headlines strikes again
air7 4y ago
Betteridge's law of headlines applies here. https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headlines https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
seydor 4y ago
This question has been addressed more than decade ago by people like Harel Shouval and Nelson Spruston. Notice the resulting form of STDP which is not quite what is seen in experiments (Whether STDP is a fundamental plasticity rule, or if it even happens in vivo is another question that has been debated). There are a lot of plasticity models proposed, this is another one. Good, but we actually need more experimental data in order to tame the beast.
vjerancrnjak 4y ago
Anyone knows what happened to the 10-part documentary that was supposed to be released in 2020? I'm really interested in the whole history of the Blue Brain project.
- pamplemoose 4y ago
  It was released. https://insilicofilm.com/ https://insilicofilm.com/

90 points by ofou 4y ago

There is the Theory of Everything and we're nearly certain it exists, we're really really close, we can smell it. Until then, we have two not so simple almost rules, quantum chromo-du-jour and pesky relativity. That's just my opinion of course. Who knows, it could be cymatic patterns carving analog ai onto the nerve cell surface, or a schoolmaster with a wooden pointer.

dwd 4y ago
Or the universe as we perceive it is a fabrication of our time-bound perception and any "Theory of Everything" is bound to fall short as reality is beyond our human perception. I would be interested to see where experiments with time crystals take us as they could be a key to discovering the true nature of reality not bound by time.

personjerry 4y ago

Can someone explain this in English?

tgv 4y ago
The title is clickbait. They've found something that seems to be true for all synapses (even though the article is too vague to make that out, and it only seems to be valid for pyramidal cells; these are important though), and it's about some aspect of plasticity: synaptic change can be predicted from calcium levels. This is not a learning rule, but a small part of the learning process. It also seems to offer a new direction in learning research, namely the influence of one synaptic change on other synapses. So it's interesting, but at a very technical level.

dwd 4y ago

Interested to see how this fits with Hawkin's 1000 Brain theory which was focused on cortical columns as modelling units. This seems to step down a level to individual voting elements.

HarHarVeryFunny 4y ago
Well, step down a few levels, if you want to put it that way. This model describes how connections between individual neurons (real physical cells, not abstract "voting units") work. Inter-neuron connections (aka synapses) are the basis of long term memories/learning. The human cortex is a thin sheet (scrunched up in our head) that would stretch out to about the size of a tea towel, that has 6 layers of neurons, with a specific inter-layer connect pattern. A cortical column is what you'd get if you took a cookie cutter and cut a small cylindrical section, like a cookie, through the cortical sheet. It'll have those 6 layers of neurons, but maybe 100 neurons total (not 6) depending on what size cookie/column you're talking about. Any model of the brain (cortex) based on cortical columns is going to be a high level functional model of that mostly abstracts away what the individual neurons are doing. At this level of abstraction, you don't really care about the detailed behavior of individual neurons, since you're assuming that their aggregate behavior can adequately be described by your higher level model.
- stefantalpalaru 4y ago

sgt101 4y ago

The title is very broad and with it's postulate hints at a massive overclaim, but this paper seems to explain something significant and interesting about how synapses work. None of which generalizes to "the brain" or "learning" really.

usgroup 4y ago

"What underlies learning in the brain might be actually simpler than previously thought despite the brain being one of the most complex objects in the known universe. A collaboration of Scientists led by the EPFL Blue Brain Project has achieved a major advance in accurately simulating the synaptic changes thought to implement learning in the neocortex, opening the door to greater understanding of learning in the brain."

mjburgess 4y ago

Does one simple rule underlie the climate? Biological systems are complex and chaotic. Denying this so that "any old model will do" is pseudoscience; and we should start calling this out.

zasdffaa 4y ago
> Biological systems are ... chaotic Are they? Seems they are extraordinarily stable. Tortoises can last two centuries, that's not the signature of chaos. What do you mean by that word?
- hprotagonist 4y ago
  A good definition of chaos that certainly applies to biological systems: Chaos: When the present determines the future, but the approximate present does not approximately determine the future. Lorenz
  - zasdffaa 4y ago
    A dead tortoise is 100% going to be dead tomorrow. A tortoise alive now is 99.995% likely to be alive tomorrow, if external threats are removed. Pretty sure that is not the behaviour of chaos under your definition.
    - hprotagonist 4y ago
      “is this neuron going to spike and if it does can we say why” is, though. “if external threats are removed” is an attempt to linearize, and therefore remove chaotic behavior. Sometimes you can pull this off and have a reasonable model at the end; sometimes you cannot. This tells you more about your model than it does about the system you’re studying.
      - zasdffaa 4y ago
        Name me a stable system that does not become destroyed when an overwhelming amount of energy is applied to it. Is a tortoise with a stick of dynamite attached on a random timer chaotic or not? Seems yes. So what are the limits that define chaos? By that you could say all is chaotic. We lack a suitable definition here.

tremon 4y ago

a flexible framework for studying cortical learning algorithms in silico What does this refer to? Are they talking about (mechanical) simulation of a brain model in a computer program, biological experimentation with chemical processes on a silicon substrate, or about translating these findings to current machine learning systems?

hocuspocus 4y ago
> simulation of a brain model in a computer program That one.

iandanforth 4y ago

TLDR; There are lots of types of neurotransmitters and lots of types of neurons, even within the general class of Pyramidal neurons. There seem to be large variations in how and when the types of neurons form and modify synapses (connections) between them. What if there were only a few factors that govern most of that variation? Using computer simulation the authors focus on calcium as a signaling mechanism, the size of synaptic spines, and known behavior of pre and post synaptic structures to create a predictive model of how and when synapses will be modified. They then compare their simulated results and model with results taken from real-world experiments and get good agreement.

achr2 4y ago
Thanks. I think this summary helps clarify the statement in the title.

jl6 4y ago

Kind of off topic from the article, but here’s another scenario to add to the AI Risk conversation: Sentience (along with consciousness, sapience, and qualia) turns out to be undefinable woo, leading to a declaration that AI is not sentient and neither are humans, and so rather than treating machines like people, we end up treating people like machines. Yeah, yeah, we already do treat people like machines etc. etc., but we risk further dehumanization if we decide the human mind is nothing special after all.

telmo 4y ago
I find that the term "woo" suffered a semantic drift in the last few decades. It used to refer to things that pretend to be scientific by using the terminology and aesthetics of science without being grounded in real empiricism. One classical example of "real woo" is homeopathy. Nowadays, "woo" is being applied to anything that science cannot model or explain. Science cannot explain consciousness? Well it must be woo then! You tell me that you experience your own consciousness, and that you are sure it exists? No, it's an illusion my poor child. An illusion of whom, you ask? That is starting to sound like philosophy, which is not science so it must be woo. Careful. Woo is becoming synonymous with "heretic" and "science" no longer means what I thought it meant. In my view, the defining aspects of science, the ones that make it such a splendorous endeavor, are modesty and doubt. All scientific theories are under the permanent risk of being falsified, otherwise they are not serious theories. There are many things we do not understand, and it might even be that this will always be the case. Some things defy our current understanding or reality, and consciousness is one of them. That doesn't make it woo, and those that pretend that it does are like the fearful religious people of previous ages, as they shout "woo"/"heretic" at those who have the temerity of harboring doubts and questions.

Georgelemental 4y ago

Betteridge's law of headlines strikes again

air7 4y ago

Betteridge's law of headlines applies here. https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headlines https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...

seydor 4y ago

This question has been addressed more than decade ago by people like Harel Shouval and Nelson Spruston. Notice the resulting form of STDP which is not quite what is seen in experiments (Whether STDP is a fundamental plasticity rule, or if it even happens in vivo is another question that has been debated). There are a lot of plasticity models proposed, this is another one. Good, but we actually need more experimental data in order to tame the beast.

vjerancrnjak 4y ago

Anyone knows what happened to the 10-part documentary that was supposed to be released in 2020? I'm really interested in the whole history of the Blue Brain project.

pamplemoose 4y ago
It was released. https://insilicofilm.com/ https://insilicofilm.com/