[ghurtado]

I realize you're making a joke, but there is no such thing as "unreferenced memories", as in, something that is no longer in use and has been removed from the brain.

Every memory your brain has ever produced is still there, even if most are beyond conscious access. Memories quite literally become a permanent part of you.

A lot of people mistakenly think of human memory as a sort of hard drive with limited capacity, with files being deleted to make room for new ones. It's very much not like that.

[pdonis]

If you are implying that human memory has infinite capacity, that's not possible. The human brain is a finite, physical thing. It can't store an infinite amount of data.

If you just mean that human memory has a finite capacity that's much larger than anyone has come close to reaching by storing the memories of a normal human lifetime, that might make sense.

Do you have any references for your statements about memory? I'm not familiar with whatever science there is in this area.

[jjk166]

The claim that everything is there does not imply infinite, or even large capacity.

Consider an exponentially weighted moving average - you can just keep putting more data in forever and the memory requirement is constant.

The brain stores information as a weighted graph which basically acts as lossy compression. When you gain more information, graph weights are updated, essentially compressing what was already in there further. Eventually you get to a point where what you can recall is useless, which is what we would consider forgotten, and eventually the contribution of a single datapoint becomes insignificant, but it never reaches zero.

[pdonis]

> The claim that everything is there does not imply infinite, or even large capacity.

It implies enough capacity to store everything. But what you describe is not storing everything.

> lossy compression

Which means you're not storing all the information. You're not storing everything.

> When you gain more information, graph weights are updated, essentially compressing what was already in there further.

In other words, each time you store a new memory, you throw some old information away.

Which the person I was responding to said does not happen.

[jjk166]

> It implies enough capacity to store everything. But what you describe is not storing everything.

I am describing what GP is describing. The original comment does not imply storage any more than mine. The comment didn't say anything about storage, you inserted that yourself.

> Which means you're not storing all the information. You're not storing everything.

Again, storing everything was never a requirement. If someone pulls up a JPEG of the Mona Lisa and asks you what it is, you say it's the Mona Lisa, despite the compressed format. Put a gaussian blur over it, make it black and white, reduce it to an 8 by 8 grid, it's still the Mona Lisa. You remember what it looks like, even if you can't perfectly recreate it. Loss of data associated with a memory is not the same as loss of the memory.

> In other words, each time you store a new memory, you throw some old information away.

No, that is not equivalent. Paint a canvas. Then paint more on the canvas. Keep doing it again and again, each brush stroke smearing those beneath. Eventually you won't be able to see your original brush strokes, but at no point in time did you remove any paint from the canvas. Your first brush strokes are still there. They contribute to the final form, even if they've been radically transformed such that their individual contribution could not possibly be isolated.

> Which the person I was responding to said does not happen.

And it doesn't. The original comment stated very clearly that memory does not work like a computer filing system. That doesn't mean the brain works like a computer filing system with unlimited storage capacity, it means the brain uses a fundamentally different architecture without analogues to storage and deletion.

[pdonis]

> storing everything was never a requirement

It might not be for you. I think it was for the poster I originally responded to. If you don't, then I guess we'll just have to disagree about that. From other posts in this discussion, I don't think I'm the only one who was interpreting what that poster said the way I interpret it.

For the rest of your post, it seems to me like you're shifting your ground. At any rate, I don't understand what your model of human memory actually is. If you have some kind of reference that describes it, that would be helpful. Your analogies are not conveying anything useful to me.

[balex]

And this description is based on what?

[ghurtado]

I didn't mean either of the things that you are wondering whether I meant, so i can't give you evidence of those things you made up yourself.

If you have questions about my comment, I'm happy to try to explain myself better

"I didn't understand you at all, so you must have meant either A or B" is not the way to reach an understanding

[pdonis]

> i can't give you evidence of those things you made up yourself.

I didn't ask for that. I asked if you have references for what you said. Even if I misunderstood you, that shouldn't be a reason for you not to give references for your statements, if you have them.

If you don't have any references to back up your statements, then I'm not sure what you're basing them on.

[vanviegen]

Your words: "Every memory your brain has ever produced is still there [..]"

How would that not imply infinite storage?

[dragonwriter]

It wouldn't imply infinite storage because human life is not infinite in time and memories do not accumulate at an infinite rate in storage consumed per unit time, so the total storage over a human lifespan is finite, so the claim can be true with finite storage.

It is almost certainly false, but it doesn't require infinite storage to be true.

[pdonis]

> human life is not infinite in time and memories do not accumulate at an infinite rate in storage consumed per unit time

Which would put it into the category of the second part of my comment--which the person I was responding to said was not relevant to what they meant.

[standardly]

> The human brain is a finite, physical thing. It can't store an infinite amount of data.

True, but it doesn't really detract from his statement because do we really know what that upper bound even is? I don't think we come close to the theoretical storage limit... So saying "every memory you have is permanently stored" is effectively true, at least true enough for a thought experiment like this. Perhaps when people live to be 200 years old and we know more about the brain we can test this, though.

I used to be weary of learning new, complex things, thinking I'd "lose" old knowledge XD

[pdonis]

> I don't think we come close to the theoretical storage limit

That was the point of the second part of my comment--which the person I was responding to said was not relevant to what he meant.

[mym1990]

Knowing almost nothing about memory and the brain, I don't know if I agree with "Every memory your brain has ever produced is still there".

Memories seem to be constructed by a group of neurons together, and it seems clear that neurodegeneration is a thing, whether by trauma or due to aging. When pathways degenerate, maybe you have a partial memory that you brain can help fill the gaps with(and often incorrectly), but that does not make it the original memory.

[vanviegen]

Bullocks. Memories fade. Or do you really believe that 'subconsciously' I still know what I had for dinner today exactly 30 years ago?

The way I understand it, it's just that, unlike on disk, the deletion process is not binary. Weak connections that are not revisited regularly gradually become weaker, until they're undistinguishable from noise (false memories).

[hn_acc1]

I mean, sure, that's true for most people. SOME people have (so-called) photographic memories and CAN tell you what they had for dinner 30 years ago, what day of the week it was, what the weather was like that day, etc..

[lux_sprwhk]

I had this experience at Big Bend State park that makes me think they are. I didn't bring enough water and camped in the primitive area. At night, I was dehydrated pretty bad. When I finally got a little sleep (it was tough to say the least), I had this vivid dream where I put a pebble in my mouth and started sucking on it to make saliva. Then I woke up for real, and I knew it because there was a lot of wind IRL, that wasn't in the dream. So I took out a coin from my back, put it in my mouth to make saliva, and got a little bit of relief. Enough for a couple hours until it was dawn, and had enough light to hike down to the restroom area.

I don't know where I got this trick. Likely some survival show or some novel. But I don't have any background in survival, otherwise, I would have brought a lot more water.

So my brain knew there was a memory that could help and made up a dream about it is my theory.