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The hippocampus as a 'predictive map'

deepmind.com

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Re: The hippocampus as a 'predictive map'

#41

Post by kortex »

mh-cx wrote: post #11
mh-cx wrote: post #10

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“?

Downvoters please explain what's so stupid about my question.

I suspect it comes across as slightly naive to this audience. The comparison between ANNs/AI and the actual human brain comes up a lot in the general media, and this leads to lots of misconceptions about AI/ANNs/deep learning, and this makes (my opinion) people in both the fields of neuroscience and machine learning a bit salty.

Inescapably, much of the high level ideas in ANN-based machine learning ("connect a bunch of nodes", "integrate and fire", "convolutional neurons/ receptive field") are cribbed directly from neuroscience.

Spiking Neural Networks (see SpiNNaker) and Hierarchical Temporal Memory (see numenta/nupic) aim for more biological plausibility, directly.

*ANNs == artificial neural networks

Re: The hippocampus as a 'predictive map'

#42

Post by [deleted] »

gnaritas wrote: post #34
dwringer wrote: post #24

Earlier quoted context omitted.

If someone only has familiarity with AI from reading passing news stories, it is reasonable to think they would have such a perception of the field. I think your diagnosis of the downvoters might be correct, but "not even wrong" seems a bit extreme. AFAIK somebody out there is probably trying to do a research paper on simulated neurotransmitters as we speak. More interesting would be if anyone had links to existing r…

> it is reasonable to think they would have such a perception of the field. It really isn't; what's reasonable is to always assume whatever you thought of in 10 seconds, has been deeply researched regardless of whether you're aware of it or not. What's reasonable is to assume researchers are vast leagues ahead of whatever shallow thoughts you have on a subject since you "know" you have a shallow understanding. The re…

[deleted]

Re: The hippocampus as a 'predictive map'

#43

Post by [deleted] »

gnaritas wrote: post #34
dwringer wrote: post #24

Earlier quoted context omitted.

If someone only has familiarity with AI from reading passing news stories, it is reasonable to think they would have such a perception of the field. I think your diagnosis of the downvoters might be correct, but "not even wrong" seems a bit extreme. AFAIK somebody out there is probably trying to do a research paper on simulated neurotransmitters as we speak. More interesting would be if anyone had links to existing r…

> it is reasonable to think they would have such a perception of the field. It really isn't; what's reasonable is to always assume whatever you thought of in 10 seconds, has been deeply researched regardless of whether you're aware of it or not. What's reasonable is to assume researchers are vast leagues ahead of whatever shallow thoughts you have on a subject since you "know" you have a shallow understanding. The re…

[deleted]

Re: The hippocampus as a 'predictive map'

#45

Post by mh-cx »

gnaritas wrote: post #34
dwringer wrote: post #24

Earlier quoted context omitted.

If someone only has familiarity with AI from reading passing news stories, it is reasonable to think they would have such a perception of the field. I think your diagnosis of the downvoters might be correct, but "not even wrong" seems a bit extreme. AFAIK somebody out there is probably trying to do a research paper on simulated neurotransmitters as we speak. More interesting would be if anyone had links to existing r…

> it is reasonable to think they would have such a perception of the field. It really isn't; what's reasonable is to always assume whatever you thought of in 10 seconds, has been deeply researched regardless of whether you're aware of it or not. What's reasonable is to assume researchers are vast leagues ahead of whatever shallow thoughts you have on a subject since you "know" you have a shallow understanding. The re…

Ok, then please forgive my ignorance. Basically that's what I was asking for (links or sources with deeper informations on the subject).

Of course I made the mistake to use “only“ where it should have been “so much“ or something. Sorry again.

Re: The hippocampus as a 'predictive map'

#46

Post by gnaritas »

mh-cx wrote: post #45
gnaritas wrote: post #34

Earlier quoted context omitted.

> it is reasonable to think they would have such a perception of the field. It really isn't; what's reasonable is to always assume whatever you thought of in 10 seconds, has been deeply researched regardless of whether you're aware of it or not. What's reasonable is to assume researchers are vast leagues ahead of whatever shallow thoughts you have on a subject since you "know" you have a shallow understanding. The re…

Ok, then please forgive my ignorance. Basically that's what I was asking for (links or sources with deeper informations on the subject). Of course I made the mistake to use “only“ where it should have been “so much“ or something. Sorry again.

Not criticizing you dude, just commenting on why there may have been down-votes; people don't like it when you imply even unintentionally that researchers are stupid and aren't looking at the right things. I have no expertise in this area so I can't point you at any relevant research, but you can bet if there's something you have a question about, someone out there has a PhD in that topic.

Re: The hippocampus as a 'predictive map'

#47

Post by pizza »

chiggins wrote: post #40
pizza wrote: post #13

Earlier quoted context omitted.

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…

Not to derail this further, but your description of Parkinson's disease is incorrect. Dopamine plays a role, but it isn't degeneration motor neurons themselves. There are many effects, but the primary symptoms WRT motor control are caused by death of dopaminergic neurons whose cell bodies reside in the substantia nigra but innervate and regulate firing of corticostriatal pre-motor pathways. [0] I did my PhD on this […

TIL, thank you

Re: The hippocampus as a 'predictive map'

#48

Post by derefr »

eru wrote: post #18
mh-cx wrote: post #10

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“?

Current AI approaches don't have that much to do with the biological brain. Despite the name 'neuronal networks' that we have history to thank for, it's better think of them as just long compositions of functions with a lot of parameters one can tweak. Historically researchers looked at activation functions that are at least somewhat justified by nature, like the sigmoid. More recently people have focused on the math…

Sure, but (our models of the functions of) neurotransmitters don't have that much to do with biology, either. For example, the local level of dopamine in a neuron is understood to be something like an encoding of a confidence interval associated with the computation, such that where synapses in the sensory (NMDA-excited) and model-predictive (AMPA-excited) regions of the brain come into contact, the dopamine in each region bubbles up as a bunch of coefficients that adjusts how comparisons between data and predictions shake out, temporarily biasing whether "branches" to error states (i.e. the activation of higher-layer neurons) are taken.

This works just as well whether you are modelling biological synapses with plasticity, or compositions of functions with training via backpropagation.

The only real difference is that NNs aren't usually "physically embodied" (i.e. embedded in a metric space with radiative signalling to non-connected but "local" neighbours) in the way they'd have to be to get the "area-effect excitation" effects of neurotransmission.

Re: The hippocampus as a 'predictive map'

#49

Post by derefr »

_0ffh wrote: post #30
dwringer wrote: post #24

Earlier quoted context omitted.

If someone only has familiarity with AI from reading passing news stories, it is reasonable to think they would have such a perception of the field. I think your diagnosis of the downvoters might be correct, but "not even wrong" seems a bit extreme. AFAIK somebody out there is probably trying to do a research paper on simulated neurotransmitters as we speak. More interesting would be if anyone had links to existing r…

IIRC there was at least some work done in the 80's and 90's about neural networks where neurons were located in a 2- or 3-D space and could emit "chemicals" that would "diffuse" through the simulated environment and influence neurons' behaviour depending on local concentration. Nothing new here, but maybe the idea is worth another look. Wouldn't be the first time an old idea turns out to be a really good one decades…

Do you know the name of the embedded-in-space work? I'd like to read more about it, but my google-fu isn't turning up anything.

Re: The hippocampus as a 'predictive map'

#50

Post by eli_gottlieb »

shuma wrote: post #20

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

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.

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