While I wouldn’t endorse the 2.5 PB figure itself, I would caution against this line of argument. It’s possible for your brain to contain plenty of information that is not accessible to your memory. Indeed, we know of plenty of such cognitive systems in the brain whose algorithms are both sophisticated and inaccessible to any kind of introspection: locomotion and vision are two obvious examples.
It might be right, I don’t know. I’m just making a local counterargument without commenting on whether the 2.5 PB figure is right or not, hence the lack of endorsement. I don’t think we know enough about the brain to endorse any specific figure, though 2.5 PB could perhaps fall within some plausible range.
a gpu contains 2.5 petabytes of data if you oversample its wires enough. if you count every genome in the brain it easily contains that much. my point being, I agree, but I also see how someone could come up with a huge number like that and not be totally locally wrong, just highly misleading.
To me any big number seems plausible, given that AFAIK people don’t seem to have run into upper limits of how much information the human brain can contain—while you do forget some things that don’t get rehearsed, and learning does slow down at old age, there are plenty of people who continue learning things and having a reasonably sharp memory all the way to old age. If there’s any point when the brain “runs out of hard drive space” and becomes unable to store new information, I’m at least not aware of any study that would suggest this.
My immediate intuition is that any additional skills or facts about the world picked up later in life, wouldn’t affect data storage requirements enough to be relevant to the argument?
For example, if you already have vision and locomotion machinery and you can play the guitar and that takes X petabytes of data, and you then learn how to play the piano, I’d feel quite surprised if that ended up requiring your brain to contain more than even 2X petabytes total of data!
(I recognise I’m not arguing for it, but posting in case others share this intuition)
I don’t immediately see the connection in your comment to what I was saying, which implies that I didn’t express my point clearly enough.
To rephrase: I interpreted FeepingCreature’s comment to suggest that 2.5 petabytes feels implausibly large, and that it to be implausible because based on introspection it doesn’t feel like one’s memory would contain that much information. My comment was meant to suggest that given that we don’t seem to ever run out of memory storage, then we should expect our memory to contain far less information than the brain’s maximum capacity, as there always seems to be more capacity to spare for new information.
Sure, but surely that’s how it feels from the inside when your mind uses a LRU storage system that progressively discards detail. I’m more interested in how much I can access—and um, there’s no way I can access 2.5 petabytes of data.
I think you just have a hard time imagining how much 2.5 petabyte is. If I literally stored in memory a high-resolution poorly compressed JPEG image (1MB) every second for the rest of my life, I would still not reach that storage limit. 2.5 petabyte would allow the brain to remember everything it has ever perceived, with very minimal compression, in full video, easily. We know that the actual memories we retrieve are heavily compressed. If we had 2.5 petabytes of storage, there’d be no reason for the brain to bother!
If we had 2.5 petabytes of storage, there’d be no reason for the brain to bother!
I recall reading an anecdote (though don’t remember the source, ironically enough) from someone who said they had an exceptional memory, saying that such a perfect memory gets nightmarish. Everything they saw constantly reminded them of some other thing associated with it. And when they recalled a memory, they didn’t just recall the memory, but they also recalled each time in their life when they had recalled that memory, and also every time they had recalled recalling those memories, and so on.
I also have a friend whose memory isn’t quite that good, but she says that unpleasant events have an extra impact on her because the memory of them never fades or weakens. She can recall embarrassments and humiliations from decades back with an equal force and vividity as if they happened yesterday.
Those kinds of anecdotes suggest to me that the issue is not that the brain would in principle have insufficient capacity for storing everything, but that recalling everything would create too much interference and that the median human is more functional if most things are forgotten.
EDIT: Here is one case study reporting this kind of a thing:
We know of no other reported case of someone who recalls
personal memories over and over again, who is both the
warden and the prisoner of her memories, as AJ reports. We
took seriously what she told us about her memory. She is
dominated by her constant, uncontrollable remembering,
finds her remembering both soothing and burdensome, thinks
about the past “all the time,” lives as if she has in her mind “a
running movie that never stops” [...]
One way to conceptualize this phenomenon is to see AJ as
someone who spends a great deal of time remembering her
past and who cannot help but be stimulated by retrieval cues.
Normally people do not dwell on their past but they are oriented to the present, the here and now. Yet AJ is bound by
recollections of her past. As we have described, recollection
of one event from her past links to another and another, with
one memory cueing the retrieval of another in a seemingly
“unstoppable” manner. [...]
Like us all, AJ has a rich storehouse of memories latent,
awaiting the right cues to invigorate them. The memories are
there, seemingly dormant, until the right cue brings them to
life. But unlike AJ, most of us would not be able to retrieve
what we were doing five years ago from this date. Given a
date, AJ somehow goes to the day, then what she was doing,
then what she was doing next, and left to her own style of
recalling, what she was doing next. Give her an opportunity
to recall one event and there is a spreading activation of recollection from one island of memory to the next. Her retrieval
mode is open, and her recollections are vast and specific.
That memory would be used for what might be called semantic indexing. So it’s not that I can remember tons of info, it’s that I remember it in exactly the right situation.
I have no idea if that’s an accurate figure. You’ve got the synapse count and a few bits per synapse ( or maybe more), but you’ve also got to account for the choices of which cells synapse on which other cells, which is also wired and learned exquisite specifically, and so constitutes information storage of some sort.
I got that from googling around the capacity of the human brain, and I found it via many sources. I definitely think that while this number is surprisingly high, I do think it makes a little sense, especially since I remember that one big issue with AI is essentially the fact that it has way less memory than the human brain, even when computation is similar in level.
Many of the calculations on the brain capacity are based on wrong assumptions. Is there an original source for that 2.5 PB calculation? This video is very relevant to the topic if you have some time to check it out:
Reber (2010) was my original source for the claim that the human brain has 2.5 petabytes of memory, but it’s definitely something that got reported a lot by secondary sources like the Scientific American.
Do you feel like your memory contains 2.5 petabytes of data? I’m not sure such a number passes the smell test.
While I wouldn’t endorse the 2.5 PB figure itself, I would caution against this line of argument. It’s possible for your brain to contain plenty of information that is not accessible to your memory. Indeed, we know of plenty of such cognitive systems in the brain whose algorithms are both sophisticated and inaccessible to any kind of introspection: locomotion and vision are two obvious examples.
I do want to ask why don’t you think the 2.5 petabyte figure is right, exactly?
It might be right, I don’t know. I’m just making a local counterargument without commenting on whether the 2.5 PB figure is right or not, hence the lack of endorsement. I don’t think we know enough about the brain to endorse any specific figure, though 2.5 PB could perhaps fall within some plausible range.
a gpu contains 2.5 petabytes of data if you oversample its wires enough. if you count every genome in the brain it easily contains that much. my point being, I agree, but I also see how someone could come up with a huge number like that and not be totally locally wrong, just highly misleading.
To me any big number seems plausible, given that AFAIK people don’t seem to have run into upper limits of how much information the human brain can contain—while you do forget some things that don’t get rehearsed, and learning does slow down at old age, there are plenty of people who continue learning things and having a reasonably sharp memory all the way to old age. If there’s any point when the brain “runs out of hard drive space” and becomes unable to store new information, I’m at least not aware of any study that would suggest this.
My immediate intuition is that any additional skills or facts about the world picked up later in life, wouldn’t affect data storage requirements enough to be relevant to the argument?
For example, if you already have vision and locomotion machinery and you can play the guitar and that takes X petabytes of data, and you then learn how to play the piano, I’d feel quite surprised if that ended up requiring your brain to contain more than even 2X petabytes total of data!
(I recognise I’m not arguing for it, but posting in case others share this intuition)
I don’t immediately see the connection in your comment to what I was saying, which implies that I didn’t express my point clearly enough.
To rephrase: I interpreted FeepingCreature’s comment to suggest that 2.5 petabytes feels implausibly large, and that it to be implausible because based on introspection it doesn’t feel like one’s memory would contain that much information. My comment was meant to suggest that given that we don’t seem to ever run out of memory storage, then we should expect our memory to contain far less information than the brain’s maximum capacity, as there always seems to be more capacity to spare for new information.
Sure, but surely that’s how it feels from the inside when your mind uses a LRU storage system that progressively discards detail. I’m more interested in how much I can access—and um, there’s no way I can access 2.5 petabytes of data.
I think you just have a hard time imagining how much 2.5 petabyte is. If I literally stored in memory a high-resolution poorly compressed JPEG image (1MB) every second for the rest of my life, I would still not reach that storage limit. 2.5 petabyte would allow the brain to remember everything it has ever perceived, with very minimal compression, in full video, easily. We know that the actual memories we retrieve are heavily compressed. If we had 2.5 petabytes of storage, there’d be no reason for the brain to bother!
I recall reading an anecdote (though don’t remember the source, ironically enough) from someone who said they had an exceptional memory, saying that such a perfect memory gets nightmarish. Everything they saw constantly reminded them of some other thing associated with it. And when they recalled a memory, they didn’t just recall the memory, but they also recalled each time in their life when they had recalled that memory, and also every time they had recalled recalling those memories, and so on.
I also have a friend whose memory isn’t quite that good, but she says that unpleasant events have an extra impact on her because the memory of them never fades or weakens. She can recall embarrassments and humiliations from decades back with an equal force and vividity as if they happened yesterday.
Those kinds of anecdotes suggest to me that the issue is not that the brain would in principle have insufficient capacity for storing everything, but that recalling everything would create too much interference and that the median human is more functional if most things are forgotten.
EDIT: Here is one case study reporting this kind of a thing:
Perhaps you are thinking of this (i think) autobiographical essay by Tim Rogers? He also talks about it in his 5th chapter of his boku no natsuyasumi review.
That memory would be used for what might be called semantic indexing. So it’s not that I can remember tons of info, it’s that I remember it in exactly the right situation.
I have no idea if that’s an accurate figure. You’ve got the synapse count and a few bits per synapse ( or maybe more), but you’ve also got to account for the choices of which cells synapse on which other cells, which is also wired and learned exquisite specifically, and so constitutes information storage of some sort.
I got that from googling around the capacity of the human brain, and I found it via many sources. I definitely think that while this number is surprisingly high, I do think it makes a little sense, especially since I remember that one big issue with AI is essentially the fact that it has way less memory than the human brain, even when computation is similar in level.
Many of the calculations on the brain capacity are based on wrong assumptions. Is there an original source for that 2.5 PB calculation? This video is very relevant to the topic if you have some time to check it out:
Reber (2010) was my original source for the claim that the human brain has 2.5 petabytes of memory, but it’s definitely something that got reported a lot by secondary sources like the Scientific American.
This thing?
https://www.scientificamerican.com/article/what-is-the-memory-capacity/
Yep, that’s the source I was looking for to find the original source of the claim.