Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Computational Power Found in the Arms of Neurons

quantamagazine.org

Post reply on HN
Print view View original

11–20 of 78 posts

Re: Computational Power Found in the Arms of Neurons

#11

Post by svara »

bonoboTP wrote: post #10

Knowing little about neuroscience outside of biology class, I've always wondered why neurons would be so simple as to just compute weighted sums and thresholds. I mean there are unicellular creatures that can do incredibly complex things, and neurons, as all cells, are ultimately the descendants of such unicellular organisms, "teamed up" into a multi-cellular creature. They have a lot of internal structure, organelle…

This is an intuition that many neuroscientists have shared, it's just that direct experimental evidence of 1) it happening at all in a non-trivial way and 2) it being relevant to the behavior of an animal is somewhat scarce.

Plus, the sum and threshold model actually gets you pretty far, as evidenced by artificial neural networks, so there might be some resistance to adding complexity that might not be necessary.

Edit: Google "dendritic computation" if you want to dig deeper.

Re: Computational Power Found in the Arms of Neurons

#12

Post by kaffeemitsahne »

ASlave2Gravity wrote: post #6

So does this point to us being biological machines? Is it already accepted that we are biological machines?

I would guess that this is near-universally accepted among neuroscientists, and people in the exact sciences in general.

Although I don't see how it would make a difference to this question where in the brain the computational power arises from.

Re: Computational Power Found in the Arms of Neurons

#14

Post by ASlave2Gravity »

valvar wrote: post #8
ASlave2Gravity wrote: post #6

So does this point to us being biological machines? Is it already accepted that we are biological machines?

You'll have to be more specific with what you mean by "machines". In what ways would machines be different from non-machines?

That's a good question.

I guess I'd say a Turing machine is my definition of a machine.

And I suppose the implication is that if we are machines, operating on a stream of input, does that make us deterministic?

EDIT: What I'm ultimately interested in is if we, as humans, are operating in a realm that logic cannot operate in. If that makes any sense? I'll probably have to define realm!

Re: Computational Power Found in the Arms of Neurons

#17

Post by buboard »

svara wrote: post #11
bonoboTP wrote: post #10

Knowing little about neuroscience outside of biology class, I've always wondered why neurons would be so simple as to just compute weighted sums and thresholds. I mean there are unicellular creatures that can do incredibly complex things, and neurons, as all cells, are ultimately the descendants of such unicellular organisms, "teamed up" into a multi-cellular creature. They have a lot of internal structure, organelle…

This is an intuition that many neuroscientists have shared, it's just that direct experimental evidence of 1) it happening at all in a non-trivial way and 2) it being relevant to the behavior of an animal is somewhat scarce. Plus, the sum and threshold model actually gets you pretty far, as evidenced by artificial neural networks, so there might be some resistance to adding complexity that might not be necessary. Edi…

clarifying that dendritic computation has been studied for decades, this one is just a new type of dendritic spike

Re: Computational Power Found in the Arms of Neurons

#18

Post by buboard »

Galaxeblaffer wrote: post #15

Anybody know where these super neurons are supposed to be located in the brain ? Are they exclusively located in the Neo Cortex ?

neocortex, from the anterior temporal lobes of epileptic patients . This kind of dendritic response has not been found the dendrites of other mammals so far. it's not a new type of neuron

Re: Computational Power Found in the Arms of Neurons

#19

Post by buboard »

bonoboTP wrote: post #10

Knowing little about neuroscience outside of biology class, I've always wondered why neurons would be so simple as to just compute weighted sums and thresholds. I mean there are unicellular creatures that can do incredibly complex things, and neurons, as all cells, are ultimately the descendants of such unicellular organisms, "teamed up" into a multi-cellular creature. They have a lot of internal structure, organelle…

they are not. the current consensus in computational neuroscience is that a neuron can be equivalent to a 2-layer or 3-layer ANN with point nonlinearities.

Edit: i am blocked from posting, so here are the refs:

https://www.ncbi.nlm.nih.gov/pubmed/20800473

https://www.ncbi.nlm.nih.gov/pubmed/25554708

https://sci-hub.tw/https://www.sciencedirect.com/science/art...

Re: Computational Power Found in the Arms of Neurons

#20

Post by buboard »

haffi112 wrote: post #5

I wonder if this is also the case for neurons in other animals. Probably it is, but it would be a stunning revelation if it is not the case.

notably this kind of dendritic spikes has not been found in other animals which have been investigated for dendritic spikes extensively (mice, rats, monkeys)
Post reply on HN