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Comment by hirundo | Hacker News Reader

"NIH researchers found that our brains may store memories in neuronal firing patterns that are replayed fractions of a second before remembering."

So it's like a phonograph record. First the track is inscribed from the source sound (storing a memory). Then the needle is placed in a groove (by some triggering experience). Then the needle traverses the inscription, playing back the recording (remembering). The brain just does it on a different chemical medium than vinyl.

To me the most magical part is however the brain so deftly places the needle in the right groove as a response to the triggering experience. That seems to go beyond the phonograph metaphor.

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That said, unlike an old gramophone which has a pretty direct linkage the final sound-waves, I believe the hints/associations that are retrieved are then subject to an astonishing amount of inference and extrapolation.

We don't remember things so much as imagine them.

The much more magical part to me is how firing these patterns of electrical activity gives rise to an experience of remembering...

Also, how exactly do they know the neuronal firing patterns happen before remembering? If you have to signal you remembered something (as in the article, a word pair), isn't there always a delay between the experience of remembering and signalling your recall? Isn't it more accurate to say the electrical signals are fired fractions of a second before communicating what you recalled? How to know if what you remember doesn't correspond 1-1 with the neuronal firing patterns taking place (or even before the electrical activity).

To me, it much more closely resembles a key-value retrieval system. I wonder if we could learn anything about that by training an artificial neural net to perform key-value storage?

Machine Learning phd student here! I am currently working on a branch of ML called Continual Learning that deals with this theme exactly. It turns out Artificial Neural Networks have a hard time recalling things they they see in the past [1].

One of the most effective strategies to counter this issue is storing and periodically replaying old training items (i.e. “memories”) for the network [2]. There are also approaches that set out to mimic what we understand of the brain and adopt cue-based approaches [3], but they don’t seem to have reached meaningful outbreaks just yet...

[1] https://en.wikipedia.org/wiki/Catastrophic_interference [2] https://arxiv.org/abs/1902.10486 [3] https://arxiv.org/abs/1711.10563

I think it's more like a graph with edges between associated bits of information. It's easy to remember things in order, but random access is hard unless you've established links for it. For example, if you memorized how to play a song, each part links to the next but harder to ask someone what is the n-th note in a song, even if they can play the song. It would explain why making associations is a useful memory technique. Traversing this graph when you aren't near what you're looking for can be hard ("it's on the tip of my tongue").

Not only that, but sometimes as happened to me recently with my own song, you completely forget how to play it until you hear it and start playing it, then suddenly you remember every little note and nuance you do did, but only while you're playing it and good luck explaining to someone what you're doing even as you're doing it.

It's odd, because it very much resembles relational memory for me. I can summon no memory just by it's name, only from it's association. The space for sole base values is very limited. The plus side is that i can generally remember every caveat and detail there is to doing a thing once I've seen it once.

Yes, this idea is called sparse distributed memory https://en.m.wikipedia.org/wiki/Sparse_distributed_memory

Yeah, my brain can prolly be 80% modeled as a Redis fork...

Content addressable memory more like.

I’ve been saying for years that it’s like a hashtable, where the key itself is hashed in a predictable quickly retrievable pattern or namespace

This article does not invalidate the idea

I wonder if you could measure someone remembering an incident, and then measure them remembering the same incident but with different imagined outcomes to find a sort of style gan embedding space for qualities of the memory?

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