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Study reveals how, when a synapse strengthens, its neighbors weaken

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Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#31
How interesting.

This looks like a lateral inhibition effect running on biochemical means that are persistent compared to the transient electrochemical phenomena of classic neuronal lateral inhibition. The latter does lots of signal processing in visual and other systems. [1]

[1] https://en.wikipedia.org/wiki/Lateral_inhibition

Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#33
post #11

Earlier quoted context omitted.

I'm still wondering about the natural equivalent of back-propagation.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673183/ Citations here: https://scholar.google.com/scholar?cites=6395717759743355511

those are backpropagating spikes, not errors

Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#34
post #27

Earlier quoted context omitted.

Amen to that, we are starting to get some of the groundwork but are far far away from a “standard model”, neuroscientists,psychiatrists and AI developers oversell their understanding in order to keep their jobs and funding.

I know of no psychologist or neuroscientist who even try for a 'standard model' level of understanding of brain function.

It’s really just the AI folks.

Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#36
post #35

So this is how Eg brainwashing works? Repeating a message strengthens the new pathways until the old connections are too weak to fire?

I would think any kind of training would have this effect. In mechanism—not purpose or ethics—brainwashing doesn’t strike me as all that different from ordinary practice.

Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#37
post #11

Earlier quoted context omitted.

I'm still wondering about the natural equivalent of back-propagation.

Isn't that mostly a supervised learning technique? Maybe the larger question is whether learning in the brain is better described as unsupervised or supervised.

I don't know how babies learn to initially use words but after that entails 99% supervised learning through school IMO nowadays. I would even argue that most new economic growth is the also the result of general supervised learning (aka, learning from others because the wealth of human knowledge is way more than anyone can learn in a million lifetimes and so the economic growth comes from continuously combining new ideas that combine other new ideas).

Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#38

My naive take on this is that it makes biologically sense to keep net expected electrical impulses approximately the same before and after strengthening. At the end of the day the brain has energy constraints. This can-be/is done functionally in ANNs but achieves a different end (avoids over-fitting) but doesn't reducing energy(compute) expenditure in dense ANNs since activation and non-activation is computed in expe…

And apart from speeding things up, it could also have a regularizing effect.

Re: Study reveals how, when a synapse strengthens, its neighbors weaken

#39
post #37

Earlier quoted context omitted.

Isn't that mostly a supervised learning technique? Maybe the larger question is whether learning in the brain is better described as unsupervised or supervised.

I don't know how babies learn to initially use words but after that entails 99% supervised learning through school IMO nowadays. I would even argue that most new economic growth is the also the result of general supervised learning (aka, learning from others because the wealth of human knowledge is way more than anyone can learn in a million lifetimes and so the economic growth comes from continuously combining new i…

But we aren't beating kids when they get facts wrong and we aren't giving them candy when they are right. So studying how the reward signal is computed should be interesting.
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