How Long Would It Take to Run Out of Memory Room?

Imagine a world were human beings lived forever. Not very likely in the near future, I realize. But my question is simply this: If humans could live forever, how long would it take before they ran out of memory room in their brains?

Thank you in advance to all who reply:)

Not a problem. Every time I learn something knew, I forget something old. I can’t remember my 8th grade locker combination. C’est le vie.

We don’t know enough about how the brain works to answer this question. Apparently some new knowledge triggers new neuron connections but I doubt if anybody knows what the exact parameters for this are.

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The things is the brain isn’t a computer, and it doesn’t work like one. Computers store information as a series of bits, literally as the presence or absence of information. Thus when a computer stores a memory of a face for example it literally memorises what parts of the face contained nose, and what parts didn’t, so a person with a large nose will simply have more information in the ‘nose’ part of the picture and less in the ‘cheek’ part pf the picture. That sort of processing works well for retaining very fine detail but it is hard to compress. It is also wasteful of space because in order to memorise a person the computer needs to memorise the face as a whole, the body as a whole, specific identifying markings at an appropriate level of detail. Then it needs to store different pictures of the person when happy, when sad and so on.

In contrast the human brain, as far as it is understood, stores information as reference information. So when a person starts life they memorise a specific face, presumably their mother’s. That initial memorisation is probably just as memory intensive as the way computer does it, relatively. But the efficiency of the brain is that every other face is stored as a reference to that. So Dad is stored as Mom with a narrower face and a beard, that’s all the information needed to distinguish those faces. Then Uncle Dave is Dad without a beard and with glasses. And the babysitter is Uncle Dave without the wrinkles, and with a longer nose. And that goes on throughout life.

The beauty of that system is that, in theory, the memory capacity of the brain is nearly infinite. Every new piece of information is referenced to previously memorized information, meaning that as the amount of information increases the amount needed for the next piece is reduced in proportion. The first face might take 10, 0000 ‘bits’, but the second face will only take 500 bits because it is just a header file referring to the first face and with a simple instruction to narrow the first face and add a beard. The next face might only take 100 bits because it’s just the first face + the second + instructions to subtract 20 years, and so forth. By the time a person knows 100 faces they can probably store the whole of humanity with header files saying “Person7s chin, person 8’s ears, person 179’s smile” and so forth. No new information is being stored per se, it is just a matter of cross-referencing existing information.

Now all those header and reference files will take up some space, so the brain will become full eventually, but it so over engineered that nobody has ever lived long enough to experience anything approaching it. People of 120 can still remember what their parents looked like, can draw pictures of their school and so on. Memories fade because of disuse, not because the brain runs out of memory capacity. As such it’s impossible to know what might happen if the brain ever reached capacity.

[QUOTE=Blake;11236213. As such it’s impossible to know what might happen if the brain ever reached capacity.[/QUOTE]

Interesting take on how the brain stores information Blake.

Well, it would seem reasonable to suppose that if the brain does reach capacity and isnt able to erase on demand (which would be my WAG), then BAD, or at least rather odd things would happen.

Of course, I seriously doubt that the brain is okay one day, then when that last tiny piece of information is input the person freezes up like a robot who has had the power switchted to off.

That actually sounds like video compression on some of the security DVRs here at work.
Products from an Israeli DVR vendor, NICE [1], have features much like what you described.
Base image, then pixel changes, then if 90% of the scene changes, new base image, then pixel changes.
I suspect DVD/etc compression works in similar fashion, just not as good as the human brain.


My theory is that by 40 years old we have used all the space we have and each new thing we learn must replace something. And we have no control over what gets replaced. That is the reason I can’t remember anything from my college years. Just watching a single episode of “I’m a Celebrity …” could cause me to forget my wife’s birthday AND where I put my keys. It’s just not worth the risk.

Speaking of which, I haven’t heard anything recently about research into analog memory. Our brains are analog, right? I remember reading about attempts to develop an artifical brain.
What Blake says sounds similar to what I remember, in that our brains remember “cues”, and are able to assemble a full memory around that cue. Maybe that’s why it sometimes takes us a moment to recall things.

Thanks, Blake. That was extremely informative.

Judging by my sons report card, approximately two school days.

Our memories of things are much closer to imagining those things than we realize. If you close your eyes, you can remember what your living room looks like. But you aren’t seeing a memorized photograph of your living room, you’re constructing an imaginary living room in your head–over there’s the TV, the walls are white, the couch is here, the kid’s LEGO is over there, and so on.

Bottom line, our memories are pretty weird and often don’t work the way we think they work.

This is also why we’re so remarkably good at remembering things that never happened. Get the wrong cue in there, and the brain can construct a full scene around that cue, with as much detail as any real memory of a real event.

Exactly. Remembering is more an act of artistic creation than accurate re-creation.

Our brains pulls “cues”, references and experiences and creates the memory from scratch every time we remember. And that memory WILL be affected by other things such as your current mood, a suggestion, or some other unrelated cue.

So on your 10 year anniversary you remember your first kiss with your wife for the 10,000th time. Everyone of those times that memory was re-created by your brain and affected by many other factors. Meaning that every time your recalled that first kiss, the less accurate the memory of your first kiss became.

This time as you are remembering it, it just happens to be raining and your brain suddenly and for some random reason uses that “cue” as it re-creates the memory. Now you will swear that that first kiss took place during a rainy day, even though it was actually sunny with not a cloud in the sky.

I thought this would be a great excuse to use the last time I forgot my anniverssary: “But honey! I DON’T WANT to remember it, because I want it to be as accurate as possible!”.

She didn’t buy it :frowning:

It seems the answer to that would be dependent on the technology to keep humans immortal. You also have issues with mental health of a 10,000 yo person. I would think memory would tough to gauge when all your immortals were stark raving mad or senile. The mechanism in this technology that fights senility would really explain all of this.

Not to be dismissive but one of my pet peeves is hearing people come up with a magical technology and then try to explain it in real world terms. A lot of the questions introduced by this technology is answered by this technology. You cant just have immortality medical procedures without addressing brain aging. So its all magic.

Im also curious as to what you think about the memory of a 30 year old person. I cant remember events in my youth as well as I did when I was, say 20. There’s something to be said that you’ll just continue to overwrite the past and never have issues with capacity.

You ask to be excused.

If we assume that long term memory is substantially stored as the inhibitory and excitatory connections between neurons (research appears to support this but the brain is complex so who knows what the final picture will look like) then there is some math you can do to guesstimate the upper limit of information based on number of neurons and synapses.

The problem is translating that number into anything meaningful because (as mentioned earlier), the brain is efficient and imprecise, it only needs to be precise enough to be effective.

If Mr. Osborne is Ozzy, he’ll totally understand.
Maybe he won’t.
I saw his Samsung Jack commercial last night, in which he discovers a new part of his house. Can’t help but love the guy. :stuck_out_tongue:

I hope it doesn’t cause a zombie issue, but I have to post to say that I googled this random question, not expecting much, and somehow just wasn’t much surprised to find this thread at the top of the results list. :stuck_out_tongue:

I’ve got no complaint.

Beautiful, Reg.