Homer Simpson said once that his brain was full and he had to forget old stuff in order to learn new. Clearly the human brain does have a limited capacity. There must come a point when there is just no more room to store fresh information. Do we have any idea what that capacity is? Has anyone, apart from Homer, ever come close to that capacity? If they did approach it could they indeed try to forget things so as to add new? Is it even possible to deliberately forget something?
If I could remember every single thing I did in one day, to run it back like a continuous film, how many days could I store? A week, a month, a year, a lifetime?
And let me apologize for my own poor brain which behind the door marked Cognitive Science has rows upon rows of empty shelves with just a few books by Daniel Dennett and Steven Pinker lying at the end of one of them.
The brain is comprised of millions of synapse’s which tie together in unlimited ways to bring back millions upon millions of memories… And probably more… They build themselves from a lead given by some slight instigation… A name, smell, etc… There are those called savants who can remember everything they’ve ever read… Thousands of books…, and the page numbers it’s on too… And they can speed read when they do that reading too… It’s fairly easy to remember an entire day by seeing a single photograph of something you did that day… There is virtually no limit to what a brain can do…, or store… Except when it’s deprived of the chemicals, amino acids, or whatever healthy brains need to work well.
That’s interesting. I hadn’t thought of the combinatorial power of synapses. Does this indeed then make the brain practically unlimited? For instance, were it possible to get it in there, could all the information on the internet fit inside our brain and still leave room for more?
A related question is how genes “build” brains. The genome is really small relative to the complexity of the brain, so again it’s the power combinatorics, and most likely the genetic changes that tweak the brain incrementally are subtle regulatory changes in level or location of expression of genes. The brain builds up a lot of its synaptic connections by interacting with the environment, but of course the general principles it follows in doing this are genetically determined. And many quite specific behavioral traits have high heritability. It’s a really interesting question just how a genetic mutation directly or indirectly effects a “rewiring” of the brain to produce a specific behavioral phenotype. We know little about this.
The human brain has been estimated to have 150 trillion synapses; each synapse is not a “bit” but is continuously variable. Memories are distributed — instead of making major changes at a few synapses, an event might effect a very tiny change in each of many hundreds of millions of synapses.
Computer algorithms may give some insights. Among various types of “neural network,” an associative memory has been proposed to emulate brain. Another well-known distributed memory algorithm demonstrates that some associative memory tasks have a small fixed cost independent of the complexity of the memorized stimulus.
I found this link, but seeing how the author says the brain has 1 billion neurons (it is actually 100 billion, plus glial cells play a role in memory too and there are 50-100x more of those than neurons) I don’t know how trustworthy it is.
Well, there must be some finite limit to the memory capacity of the brain, given that it’s made up of matter, and a finite number of particles. And of course any estimate based on just the number of particles is going to be a huge overestimate, given that the brain doesn’t store information perfectly optimally.
In practice, though, I suspect that the maximum practical capacity is just one lifespan’s worth of memories, on the ground that there can’t have been any pressure to evolve a system with any more capacity than that.
Yes, that would certainly be a good null hypothesis. The brain burns about 20% of the food & oxygen that we use, so we’d expect strong selection to make a brain only as big it needs to be. Animals in general tend to be only as smart as they need to be, and in many evolutionary niches it’s cheaper to just make “firmware” with relatively inflexible behavior patterns. We lucked out that our in our niche being super-smart with flexible intelligence was an advantage, giving us brains that can do a whole lot of interesting stuff.
I wouldn’t really know how high that limit is… But the hypnotism’s that brings back what are thought to be other lives is now thought to be those of our parents and grandparents memories…, and so on back for many generations I’m sure… Our long strings of so called junk DNA has all this information stored but we don’t know how to access it otherwise… It has all their memories too… The why of with hypnotism that people can all of a sudden play the piano, talk a foreign language, or know other things they do not know in their current life…
It all makes sense… There’s no such thing as ‘instinct’… It’s all remembered things from our parents and on back to distant ancestors… It’s all stored in our genes… Our DNA… And the synapse work to search it out what it’s clued into looking for…
They build themselves from a lead given by some slight instigation… A name, smell, etc… There are those called savants who can remember everything they’ve ever read… Thousands of books…, and the page numbers it’s on too… And they can speed read when they do that reading too… It’s fairly easy to remember an entire day by seeing a single photograph of something you did that day… There is virtually no limit to what a brain can do…, or store… Except when it’s deprived of the chemicals, amino acids, or whatever healthy brains need to work well.