A recent TV show interviewed a man who read the Encyclopedia Britannica from beginning to end, attempting to remember most of the data. He claimed to remember a lot, but did not claim to remember all. This got me to thinking about the limits of brain memory capacity.

When I was a teenager, my friend, Steve, and I discussed the memory capacity of the human brain. We wondered if it was analogous to a room full of objects. At some point you would have to throw an old object out in order to make room for a new one. Due to this discussion, we made a list of facts that seemed unworthy of permanent storage in memory. We decided that we would try to not remember such facts.

To this day, I tend not to remember what I ate yesterday. I probably use more brain capacity to suppress the memory than what would be required to remember what I ate.

It is obvious that there is a limit to the memory capacity of the brain, but the analogy with a room full of objects does not come close to modeling that capacity.

The real questions are: Does anybody come close to reaching the limit of their memory capacity? If so, what happens when you get close to that limit? At some point in your life, might it be difficult or impossible to create new memories due to being close to capacity limit? Do you discard some old data to make room for new data? Perhaps no person ever comes close to the limit because there is some regular process that discards data, or because the limit is beyond what is required for a life time of data collecting.

The brain is not organized like a computer. There is no clear divison between data storage and processing storage. The data storage and the functional processes are intertwined some how. We actually change or rewire the circuitry as we store data in our memory. Bits of related data are scattered rather than being in close physical proximity. There is nothing like an index. The organization is more analogous to a large number of hyper-links connecting the various neurons used to store related data.

It seems a bit complicated to discard anything. Far more complex than merely deleting a file from a hard disk. For example, data about Cherry trees is linked to and germixed with data about specific forests, forests in general, other types of trees, vegetation other than trees, squirrels & birds (who live in trees), and who knows what else. Data specifying shapes of the leaves, berries, & flowers are stored separately from the color data, and the motor data required to verbalize the pertinent concepts is stored in another area of the brain.

I am not sure what I have forgotten and what is merely not retrievable. Many times I cannot remember some fact like the name of an actor in a movie seen a long time ago, only to have the name pop up an hour or a day later. At other times , the name seems lost forever unless somebody tells me or I do some research. In the latter case is the data no longer there or is it merely difficult to retrieve?

I remember reading an interesting story about a Russian woman who remembered *everything*. She eventually went nuts and had to be locked up in a mental institution..horrible way to live.

'Forgetting' is an ability we all take for granted. There's no set limit to how much a brain can store, as a person could spend their entire life learning and never fill it up. Its like a special compression, brain performance and intelligence increase the more you know, but begins to decrease as you overload..

If you've got a good brain, it can probably handle way more than one with a low metabolism. But not in a way that can be quantified, such as 'terabytes' since, as you pointed out our brains aren't traditional computers. That said, brain compression is so great that the capacity could be near limitless.

as you learn so many things, the neurons used to store things move closer togetehr allowing for more to be created, essentially, you brain becomes evermore complex in order to store data,

thtink of it as a harddrive, except when the harddrive runs out of space it cuts filaments in half so twice the amount af data can be stored

Vslayer: I would expect the connectivity to become more complex as you learn and remember more data.

I do not believe that the size or spacing of the neurons change significantly. Do you have reference for your statement?

Well, there are autistic savants that can tell you everything that happened to them every day of their lives in exquisite detail. Then they can recite the phone book, encyclopedia, draw a map from memory, multiply 6 digit numbers in their head, or some other amazing "trick" or "feat" of brain power.

The question is, is their amazing recall a tradeoff they receive from lack of social apparatus in the brain? Are the areas normally devoted to such "human" things as gossiping and whatnot instead filled with memory? Or is their memory just like everyone else's memory and they merely have the means of accessing it?

I bet on the latter. I think that memories are stored on top of each other, so that they might be obscured and associated mistakenly with other memories at times, but they never really vanish. They merely lose potency.

You know, when I was 12 years old I was eager to become a boy scout. For the initiation ceremony or whatever it was I had to memorize the scout motto and the scout creed (I think that was what they called it. Could be wrong.) I don't remember the motto, but I learned the creed so well that it is permanently emblazoned in my memory in bold-faced font.

Ready?

A scout is trustworthy, loyal, helpful, friendly, courteous, kind, obedient, cheerful, thrifty, brave, clean, and reverant.

Now, I can say this at the drop of a hat in 15 seconds. I have no clue why this remains so clear. I don't even remember for sure if it's the creed or something else. I barely remember parts of the motto. Wait. Oath. So the above is the motto. Yeah, that's the ticket. So, the oath, barely recall a bit on "I will do my duty to God and to country. Obey the scout law... blah" That's it. But the other remains indelibly marked on my grey matter, ready to be called forth at a moment's notice.

Vslayer,

as you learn so many things, the neurons used to store things move closer togetehr allowing for more to be created, essentially, you brain becomes evermore complex in order to store data,

It's more like a pattern is laid over a pattern is laid over a pattern. That's part of the function of dreams (IMO) to sort these memory patterns to determine which patterns can fit on top of each other and how to associate these stacked patterns with a trigger event such that one specific pattern might be pulled from the pile.

If we could figure out how to do this with computer storage medium, we'd probably have multi-terabyte drives or better.

The problem, of course, is the possibility of error. I imagine that there is some type of error checking in the brain, but memories are notoriously faulty (in most). So, fuzziness at the edges is the price we pay for our astounding capacities.

Fuzziness at the edges is the price of life.

But, if we use redundant storage locations, much of the fuzziness could be removed. An average between varying patterns could be found. Never quite perfect, but approaching perfection. Limiting towards perfection. Follow?

i have no reference but as with all parts of our body, they grow more cells as they develop, so it only makes sense that you would develop new neurens if you wanted to remember more, and if you have limited space but more neeurons they woud be closer togetehr

with muscles we grow them bigger as they get put te use and grow more cells, but with limited skull size it would just group closer

We do not develop new neurones when we run out off 'space' to remember things. You can find out quite easily that the brain stops developing in the early 20's.

Read (http://www.doc.ic.ac.uk/~nd/surprise_96/journal/vol2/cs11/article2.html) the first paragraph for a simple explanation of learning.

It physically stops growing in the early 20's, but it tweaks itself (so to speak) until well past 40.

I have another question : is our intellectual capacity related to the number of convolutions in the neocortex?

1) Adult neurogenesis is well documented in many species. I think it does occur in humans too, but it is extremely limited. In any case it is usually restricted to very specific areas (like the olfactory regions in rodents and the dentate gyrus of the human hippocampus).

2) The physical architecture of the brain continues to change throughout life, but this is mostly due to the modification of existing synaptic connections, the formation of new ones, and the pruning of old ones (not to the addition of new cells in large numbers).

By the way, it is a mistake to think that learning is always mediated by the formation of new connections. The number of synapses in the brain peaks around age four, and declines steadily thereafter. But learning can be embodied in synapse elimination ('synaptic pruning') as well as in synapse addition. If all network connections are set at their maximum strength, you have no variation in which to encode meaning.

3) My personal experience has been that I definitely have less clear space in my brain now than I once did. I relate this specifically to having gone through medical school. The first two years of med school consist of forcing an enormous amount of factual information into your brain. I think I've exhausted my declarative memory. Frankly, I now often find that I cannot remember the names of people I know extremely well, people I've known for years. This had never happened to me before medical school, and I doubt that my organism became so run down in two years as to affect my memory in such an extreme way. I used to be very good at remembering trivia (even played Quiz Bowl in college a bit); now I'm lucky if I can remember the main point of the paper I read ten minutes ago.

Fascinating information on brain architecture and memory storage, folks.

Has anyone else seen the Ben Affleck movie Paycheck? The hero agrees to submit to targeted amnesia of everything he's experienced back to a specific point in time - the impression it gave was that specific synaptic connections could be identified and severed, rather than simply conditioning his mind to block the memories (as a hypnotist could). Might this kind of "hardware" brainwashing be technically possible?

hypatia said 3) My personal experience has been that I definitely have less clear space in my brain now than I once did. I relate this specifically to having gone through medical school. The first two years of med school consist of forcing an enormous amount of factual information into your brain. I think I've exhausted my declarative memory. Frankly, I now often find that I cannot remember the names of people I know extremely well, people I've known for years. This had never happened to me before medical school, and I doubt that my organism became so run down in two years as to affect my memory in such an extreme way. I used to be very good at remembering trivia (even played Quiz Bowl in college a bit); now I'm lucky if I can remember the main point of the paper I read ten minutes ago.



I don't think this is necessarily a bad thing but it shows a sort of trade off. I have been experiencing this same thing for a few years. I am in a business that is fast paced where I have to know a lot about a variety of things but all within the same field. I have never been more mentally exhausted in my entire life. All I do is think, research and solve problems each and every day but always in the same realm...IT.

I find that since this started it is hard for me to focus on a great many things such as my writing and philosophy. Since I have been here I have given myself headaches a few times just reading what some of you people post.

I think that in some way when you get stuck in a rut...or stay in one way or pattern of thinking/learning that it is difficult to move to something different. This does not mean that I have pushed anything out of my head because I haven't practiced or discussed it, it just needs a little defrag.

I also believe that we forget things because at some point subconsciously we consider them to be not of use or most likely something that doesn't matter to you.

For instance. If someone tells me as I walk out the door to not forget to pick up some toilet paper....I will forget it before I turn around the corner. Why? Probably because I don't have to go to the bathroom. It is not my immediate need therefore I file it away and because my head is so busy plotting out my day and fixing things that when I finally remember it's when I'm home after work in the bathroom!

This is a pretty complex subject though and I think a lot of what has been posted so far is excellent.