8 ms·

The hippocampus as a 'predictive map'

201 points by runesoerensen 9y ago

m3kw9 9y ago
Are the structure same throughout the areas where we think in general? Otherwise there could be some sort of programming involved to get the brain to think predictively
gregatragenet3 9y ago
It's too bad, their prior papers were generally open for anyone to read. These new papers appear to be behind paywalls :(
- pazimzadeh 9y ago
  Obligatory Sci-Hub link https://sci-hub.cc/https://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.4650.html https://sci-hub.cc/https://www.nature.com/neuro/journal/vaop...
- sukunrt 9y ago
  It's open for anyone to read, the article links to nature which is behind paywall. https://deepmind.com/research/publications/ https://deepmind.com/research/publications/ the download link is open. https://www.biorxiv.org/content/biorxiv/early/2017/07/25/097170.full.pdf https://www.biorxiv.org/content/biorxiv/early/2017/07/25/097...
- deleted 9y ago
  [deleted]
- return0 9y ago
  i actually have access, but nature.com was down at the moment. Sci-hub it is
- andrepd 9y ago
  Thank god for Sci-Hub, then. That reminds me, I should donate.
pizza 9y ago
Relevant: A compressed sensing perspective of hippocampal function (2014): Hippocampus is one of the most important information processing units in the brain. Input from the cortex passes through convergent axon pathways to the downstream hippocampal subregions and, after being appropriately processed, is fanned out back to the cortex. Here, we review evidence of the hypothesis that information flow and processing in the hippocampus complies with the principles of Compressed Sensing (CS). The CS theory comprises a mathematical framework that describes how and under which conditions, restricted sampling of information (data set) can lead to condensed, yet concise, forms of the initial, subsampled information entity (i.e., of the original data set). In this work, hippocampus related regions and their respective circuitry are presented as a CS-based system whose different components collaborate to realize efficient memory encoding and decoding processes. This proposition introduces a unifying mathematical framework for hippocampal function and opens new avenues for exploring coding and decoding strategies in the brain. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126371/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126371/
dontreact 9y ago
I don't know how this theory fits in with patient H.M. who was still capable of many types of learning and planning, despite having his entire hippocampus removed. https://en.wikipedia.org/wiki/Henry_Molaison https://en.wikipedia.org/wiki/Henry_Molaison At the least such a broad sweeping theory of how a brain region works should address how it fits in with evidence with the most famous lesion (and deeply studied) patient who did not have said brain area?
- saurik 9y ago
  > "The researchers found, to their surprise, that half of H.M.'s hippocampus had survived the 1953 surgery..."
- SubiculumCode 9y ago
  As much as I love the hippocampus (topic of my dissertation), I had to constantly remind myself that there is a lot of other brain.
mh-cx 9y ago
Reading about rewards in AI context makes me wonder, why current AI only focuses on the network topology aspect of natural intelligence. What about the neurotransmitters like dopamine or serotonine? Could they (or more specific: their effects) be key to an AI that feels more “natural“?
- mh-cx 9y ago
  Downvoters please explain what's so stupid about my question.
  - pizza 9y ago
    I upvoted you, and I'm actually glad you asked the question despite downvotes. I imagine those who did are of the opinion that essentially you're ascribing too much function to the neurotransmitters themselves, as opposed to the contexts in which the presence of the neurotransmitters are used as signals. Take a look at this brain schematic here [0]. I vehemently disagree with some of the presented-as-fact ideological aspects of the article, but the depiction of neurotransmitters working differently in different brain regions is illustrative. i.e., a dopamine molecule does not already constitute a meaningful coordinate system -- it doesn't have a meaning in and of itself, such as "the reward molecule", or euphoria/"feel-good"/"addiction trap"/excitement molecule) in the brain. Rather, the dopamine molecule has locally-interpreted semantics. To make this more concrete with examples of different aspects of dopamine alone: - "dopamine is known to encode the confidence level of motor predictions" - Scott Alexander, psychiatrist [1] - saturating the synaptic cleft between neurons with released (or non-recycled) dopamine is a part some euphoric processes (e.g. drugs, orgasm, gambling) in the striatum negra - 'excess' (not a simple thing to determine for individuals imo) dopamine is related with psychosis (not per se causally), and antipsychotics are often designed to blunt dopamine transmission However, - dopamine transmission is also fundamentally necessary for muscle movement, in the motor cortex - additionally, the conscious sensation of dopamine is highly dependent upon the frequency of dopaminergic neuron spikes - Parkinson's disease is (iirc, said to be,) the result of the degeneration of motor neurons; shakiness, problems sleeping; What does that mean for AI? Well, if we want to go beyond network topology, and start to use new varieties of component substrates, the individual types of signals they represent must either a) be fairly meaningless outside of a specific context or b) not be suited for learning from evidence and generalization of data. Check out [2], [3], and [4] for more. [0] http://www.nationalgeographic.com/magazine/2017/09/the-addicted-brain/ http://www.nationalgeographic.com/magazine/2017/09/the-addic... [1] http://slatestarcodex.com/2017/09/12/toward-a-predictive-theory-of-depression/ http://slatestarcodex.com/2017/09/12/toward-a-predictive-the... [2] https://www.edge.org/conversation/stephen_wolfram-ai-the-future-of-civilization https://www.edge.org/conversation/stephen_wolfram-ai-the-fut... (not that i am a huge fan of wolfram :P) [3] https://www.edge.org/responses/what-scientific-concept-would-improve-everybodys-cognitive-toolkit https://www.edge.org/responses/what-scientific-concept-would..., ctrl-f "biological" [4] https://en.wikipedia.org/wiki/Multi-state_modeling_of_biomolecules https://en.wikipedia.org/wiki/Multi-state_modeling_of_biomol...
eli_gottlieb 9y ago
Hmmm. I'll need to read more closely later and make a real comment, but since when did Gershman or anyone at DeepMind get on the predictive-coding train? Nonetheless, this kind of algorithm sounds like exactly what I expect from a predictive brain that cares fundamentally about trajectories.
- mannigfaltig 9y ago
  What are your thoughts on this paper?
shuma 9y ago
Numenta have been doing this for many years now, https://numenta.com/ https://numenta.com/
- eli_gottlieb 9y ago
  Can you and others please stop reading actual neuroscience and saying, "oh, Numenta did this already"? * Firstly, you're reading a neuroscience paper. It's biology! Numenta is not biology. * Secondly, Numenta makes a lot of big claims and then never publishes anything. This has gotten as if we were responding, "Simpsons did it!" to jokes which, in fact, The Simpsons had never aired, based on the supposition that since they once did a joke with vaguely similar vocabulary, it must have been the same as this joke.
rayuela 9y ago
Just $225 to read the actual paper... what a steal! If someone would so kindly share that pdf on here I'd greatly appreciate it. Nvm found it: https://www.biorxiv.org/content/early/2016/12/28/097170 https://www.biorxiv.org/content/early/2016/12/28/097170
- agumonkey 9y ago
  ah well good catch usually I try digging the authors in case preprints are on their own webpage and just in case people miss it, the latest version is also there https://www.biorxiv.org/content/early/2017/07/27/097170 https://www.biorxiv.org/content/early/2017/07/27/097170
- itschekkers 9y ago
  theres a website called sci-hub (which maybe illegal) that you can use to get almost any paper in a STEM field, especially from major journals. you type www.sci-hub.cc/ and then paste the DOI of the paper. it takes you straight to the pdf!
  - SubiculumCode 9y ago
    Or you can contact the researcher, who are generally happy to share our research via email. Or check their researchgate.
    - neurokim 9y ago
      Truth :) https://rdcu.be/wnSU https://rdcu.be/wnSU
  - duozerk 9y ago
    Also if it doesn't work (happens from time to time) or disappears, they have a tor mirror that works consistently: scihub22266oqcxt.onion.
- neurokim 9y ago
  Also final version on readcube: http://rdcu.be/wnSU http://rdcu.be/wnSU
neurokim 9y ago
This link should work for full text, final version, no paywall http://rdcu.be/wnSU http://rdcu.be/wnSU

201 points by runesoerensen 9y ago

Are the structure same throughout the areas where we think in general? Otherwise there could be some sort of programming involved to get the brain to think predictively

gregatragenet3 9y ago

It's too bad, their prior papers were generally open for anyone to read. These new papers appear to be behind paywalls :(

pazimzadeh 9y ago
Obligatory Sci-Hub link https://sci-hub.cc/https://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.4650.html https://sci-hub.cc/https://www.nature.com/neuro/journal/vaop...
sukunrt 9y ago
It's open for anyone to read, the article links to nature which is behind paywall. https://deepmind.com/research/publications/ https://deepmind.com/research/publications/ the download link is open. https://www.biorxiv.org/content/biorxiv/early/2017/07/25/097170.full.pdf https://www.biorxiv.org/content/biorxiv/early/2017/07/25/097...
deleted 9y ago
[deleted]
return0 9y ago
i actually have access, but nature.com was down at the moment. Sci-hub it is
andrepd 9y ago
Thank god for Sci-Hub, then. That reminds me, I should donate.

pizza 9y ago

Relevant: A compressed sensing perspective of hippocampal function (2014): Hippocampus is one of the most important information processing units in the brain. Input from the cortex passes through convergent axon pathways to the downstream hippocampal subregions and, after being appropriately processed, is fanned out back to the cortex. Here, we review evidence of the hypothesis that information flow and processing in the hippocampus complies with the principles of Compressed Sensing (CS). The CS theory comprises a mathematical framework that describes how and under which conditions, restricted sampling of information (data set) can lead to condensed, yet concise, forms of the initial, subsampled information entity (i.e., of the original data set). In this work, hippocampus related regions and their respective circuitry are presented as a CS-based system whose different components collaborate to realize efficient memory encoding and decoding processes. This proposition introduces a unifying mathematical framework for hippocampal function and opens new avenues for exploring coding and decoding strategies in the brain. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126371/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126371/

dontreact 9y ago

I don't know how this theory fits in with patient H.M. who was still capable of many types of learning and planning, despite having his entire hippocampus removed. https://en.wikipedia.org/wiki/Henry_Molaison https://en.wikipedia.org/wiki/Henry_Molaison At the least such a broad sweeping theory of how a brain region works should address how it fits in with evidence with the most famous lesion (and deeply studied) patient who did not have said brain area?

saurik 9y ago
> "The researchers found, to their surprise, that half of H.M.'s hippocampus had survived the 1953 surgery..."
SubiculumCode 9y ago
As much as I love the hippocampus (topic of my dissertation), I had to constantly remind myself that there is a lot of other brain.

mh-cx 9y ago

Reading about rewards in AI context makes me wonder, why current AI only focuses on the network topology aspect of natural intelligence. What about the neurotransmitters like dopamine or serotonine? Could they (or more specific: their effects) be key to an AI that feels more “natural“?

mh-cx 9y ago
Downvoters please explain what's so stupid about my question.
- pizza 9y ago
  I upvoted you, and I'm actually glad you asked the question despite downvotes. I imagine those who did are of the opinion that essentially you're ascribing too much function to the neurotransmitters themselves, as opposed to the contexts in which the presence of the neurotransmitters are used as signals. Take a look at this brain schematic here [0]. I vehemently disagree with some of the presented-as-fact ideological aspects of the article, but the depiction of neurotransmitters working differently in different brain regions is illustrative. i.e., a dopamine molecule does not already constitute a meaningful coordinate system -- it doesn't have a meaning in and of itself, such as "the reward molecule", or euphoria/"feel-good"/"addiction trap"/excitement molecule) in the brain. Rather, the dopamine molecule has locally-interpreted semantics. To make this more concrete with examples of different aspects of dopamine alone: - "dopamine is known to encode the confidence level of motor predictions" - Scott Alexander, psychiatrist [1] - saturating the synaptic cleft between neurons with released (or non-recycled) dopamine is a part some euphoric processes (e.g. drugs, orgasm, gambling) in the striatum negra - 'excess' (not a simple thing to determine for individuals imo) dopamine is related with psychosis (not per se causally), and antipsychotics are often designed to blunt dopamine transmission However, - dopamine transmission is also fundamentally necessary for muscle movement, in the motor cortex - additionally, the conscious sensation of dopamine is highly dependent upon the frequency of dopaminergic neuron spikes - Parkinson's disease is (iirc, said to be,) the result of the degeneration of motor neurons; shakiness, problems sleeping; What does that mean for AI? Well, if we want to go beyond network topology, and start to use new varieties of component substrates, the individual types of signals they represent must either a) be fairly meaningless outside of a specific context or b) not be suited for learning from evidence and generalization of data. Check out [2], [3], and [4] for more. [0] http://www.nationalgeographic.com/magazine/2017/09/the-addicted-brain/ http://www.nationalgeographic.com/magazine/2017/09/the-addic... [1] http://slatestarcodex.com/2017/09/12/toward-a-predictive-theory-of-depression/ http://slatestarcodex.com/2017/09/12/toward-a-predictive-the... [2] https://www.edge.org/conversation/stephen_wolfram-ai-the-future-of-civilization https://www.edge.org/conversation/stephen_wolfram-ai-the-fut... (not that i am a huge fan of wolfram :P) [3] https://www.edge.org/responses/what-scientific-concept-would-improve-everybodys-cognitive-toolkit https://www.edge.org/responses/what-scientific-concept-would..., ctrl-f "biological" [4] https://en.wikipedia.org/wiki/Multi-state_modeling_of_biomolecules https://en.wikipedia.org/wiki/Multi-state_modeling_of_biomol...

eli_gottlieb 9y ago

Hmmm. I'll need to read more closely later and make a real comment, but since when did Gershman or anyone at DeepMind get on the predictive-coding train? Nonetheless, this kind of algorithm sounds like exactly what I expect from a predictive brain that cares fundamentally about trajectories.

mannigfaltig 9y ago
What are your thoughts on this paper?

shuma 9y ago

Numenta have been doing this for many years now, https://numenta.com/ https://numenta.com/

eli_gottlieb 9y ago
Can you and others please stop reading actual neuroscience and saying, "oh, Numenta did this already"? * Firstly, you're reading a neuroscience paper. It's biology! Numenta is not biology. * Secondly, Numenta makes a lot of big claims and then never publishes anything. This has gotten as if we were responding, "Simpsons did it!" to jokes which, in fact, The Simpsons had never aired, based on the supposition that since they once did a joke with vaguely similar vocabulary, it must have been the same as this joke.

rayuela 9y ago

Just $225 to read the actual paper... what a steal! If someone would so kindly share that pdf on here I'd greatly appreciate it. Nvm found it: https://www.biorxiv.org/content/early/2016/12/28/097170 https://www.biorxiv.org/content/early/2016/12/28/097170

agumonkey 9y ago
ah well good catch usually I try digging the authors in case preprints are on their own webpage and just in case people miss it, the latest version is also there https://www.biorxiv.org/content/early/2017/07/27/097170 https://www.biorxiv.org/content/early/2017/07/27/097170
itschekkers 9y ago
theres a website called sci-hub (which maybe illegal) that you can use to get almost any paper in a STEM field, especially from major journals. you type www.sci-hub.cc/ and then paste the DOI of the paper. it takes you straight to the pdf!
- SubiculumCode 9y ago
  Or you can contact the researcher, who are generally happy to share our research via email. Or check their researchgate.
  - neurokim 9y ago
    Truth :) https://rdcu.be/wnSU https://rdcu.be/wnSU
- duozerk 9y ago
  Also if it doesn't work (happens from time to time) or disappears, they have a tor mirror that works consistently: scihub22266oqcxt.onion.
neurokim 9y ago
Also final version on readcube: http://rdcu.be/wnSU http://rdcu.be/wnSU

neurokim 9y ago

This link should work for full text, final version, no paywall http://rdcu.be/wnSU http://rdcu.be/wnSU