How much information can the brain hold?

The people who have super memories actually have a certain part of their brain that is physicaly larger. They see some evidence of people in professions that require a lot of memory also have a slightly larger area of the brain that hold memory. Professions like doctors and scientists. But, we use only a small portion of our brains, so for the most part I would say as far as the average person is concerned the possibility is, or at least would be perceived as, infinite from our perspective. But, it isn’t infinite for everyone. A friend of mine works with retarded children and their capacity for memory is extremely low.

We can work on our memories, make a conscious effort to remember. Actress Marilu talks about growing up playing memory games and that she does it with her children, but they don’t seem to have the same extreme of super memory that she does.

I am working on a research project studying those people with abnormally good autobiographical memory (people with Highly Superior Autobiographical Memory [HSAM] or hyperthymesia).

One thing we’ve found about memory in general, that seems to also apply to these people, is that memory doesn’t work like a video. Instead, memories are reconstructed out of bits and pieces of things that are in your brain.

When we recall memories, it feels like we are recalling a static recording of something that happened—but what we are really doing is constructing a plausible series of events that may have happened based on the information available to use at the time we recall it. So all you need to reconstruct those memories are small bits and pieces—kind of like how, to construct every word you know, you don’t need to create each word fresh; you can build it out of the letters of the alphabet.

People with HSAM are reconstructing memories in the same way that you and I are. They just seem to be better at elaborating and building big, rich networks of memories—their memories appear to be more interconnected with each other, which makes them easier to reconstruct and easier to recall.

So this is a long and roundabout way of saying that in order to store all of those memories, your brain doesn’t actually need to store a ton of information—it just needs to be able to connect pieces together very well.

@nikipedia I was thinking about that. I took cognition and learned that whole “memory isn’t recorded like a video” analogy, which makes sense. The way I see it then, is like the brain uses “legos” to construct a memory. But then, well, how many “legos” can the brain hold to construct memory then?

@nikipedia Years ago I was taught that people with good memories have a better filing system, so they can retrieve memories with many different cues. It also might explain how IQ is connected to memory, because people with high IQ can pull on previously learned information and relate it to new information, whether it be the same topic or even a different one.

I also have heard that memories tied to emotion are “etched” pretty deep in the brain, and triggering that same emotion can bring up the memories of the traumatic incident, which might explain PTSD.

Where is the research on those things? I wonder if emotion sometimes interferes with memory also? I know when I go through an extended bad time my memories kind of fog over. I think it is a gift most of the time.

2.5 petabytes

@ScottyMcGeester, I don’t think there’s any way to answer that. If you could define what each unit of memory was, we could try to estimate how many units the brain could hold, but I would get stuck on that first step, myself.

That said, people have tried to estimate how many “bytes” of information the brain can hold: http://www.slate.com/articles/health_and_science/explainer/2012/04/north_korea_s_2_mb_of_knowledge_taunt_how_many_megabytes_does_the_human_brain_hold_.html

@JLeslie, it’s true, emotion does tend to have an enhancing effect on memory. Usually when scientists talk about this, they’re talking about emotions that are strong enough to elicit a physiological stress response (release of cortisol or norepinephrine). But only certain kinds of situations will elicit those responses (physical pain, social stress) and the effects of emotion on memory extend beyond that. The problem is that emotion is not very well-defined and is hard to study—it is similar to mood, or affect, but not really the same as either one.

I think what you are talking about is more like mood—there are studies that show that people who are having symptoms of depression (even if not full-on depression) have some memory impairments, but they also tend to have general fogginess—difficulty concentrating, etc.

@nikipedia How do you feel about using the forget drugs to treat people who went through or witnessed traumatic events of violence? I don’t remember the name of the drugs they use for this.

The point you make about mood is very interesting. So, people who are happier possibly tend to have stronger memories?

@JLeslie, people have tried to use beta-blockers (propranolol) to do this—they were originally prescribed as blood pressure medication. It seems to work, kind of. It seems harmless to me—the drugs don’t make you forget anything, they just dampen the emotional impact, so instead of having a SUPER strong memory, you have a normal strength memory. It could be a very good thing. If they really interfered with your memory we probably would have seen that in the people using them for heart medicine over the years.

Here is something related that I think is even more interesting—one of the girls in my lab published a study a few years ago showing that rape victims who were given a specific kind of morning after pill had fewer PTSD symptoms 6 months later.

@nikipedia Interesting. I wonder if it is hormones, or some sort effect from feeling like something is actively being done. Kind of like having some control over the situation when that type of violence is such an extreme loss of control.

@JLeslie, they studied 2 emergency contraception pills, 1 that was a progestin + estrogen, and one that was progestin-only, and only one of them had an effect. So it looks like it was the hormones.

Good point. I was overlooking that one pill was more effective.

I used to know this….

I have seen suggestions that memory and other brain functions are due to emergent behavior, analogous to the behavior of an ant colony or beehive. Individual ants and bees are not capable of complex behavior but when they get together, they can do some pretty sophisticated things due to the way that they interact.

I wonder if there might be a random component to neural behavior. What if neurons occasionally send out random signals that are usually not very helpful or harmful but which occasionally lead to a spark of creativity?

All of it.

That is a wonderful question. Unlike a computer, the capacity of the brain can not be measures only in terms of the amount of data it can store or the number of computational operations it can perform per second.

When it comes to raw data capacity or number of operations per second the best human brain can perform, the computer would seem to win every time.

When we look at the kind of operations that can be performed by even the average human brain that every the most mighty super computer has yet to be able to do we must look beyond capacity.

The finely tuned and well educated human brain is capable of defining and operating of types of problems that computers show no capacity to undertake. Humans seem to be able to design a wide range of unique solutions to a range of problems that it is still difficult to even adequately express in any computer language.

Computers had do mathematical operations on large collections of numbers at amazing speed with no requirement for rest. Some can even be programmed to draw on the recorded results of previous attempts to solve similar problems which resembles what we call learning. When it come to writing programs to attempt to resolve the many kinds of human problems that do not easily lend themselves to being expressed in any of the many computer languages, the best computer scientists acknowledge that despite their capacity and computational speed, even the best computers still seem rather incompetent to even express the kind of problems that most human brains can, with experience, understand and sometime develop many alternate solutions to deal with those problems.

To get to the root of your original question, given adequate time to interpret, categorize and encode the pieces of information and how they relate to each other, the capacity of the brain to retain and retrieve such information continues to exceed all apriori estimates. In other words, we continue to be amazed at how much information the brain can hold of things it understands.

Computers can store huge amount of numbers that mean nothing at all to the computer.

Yes, there’s a physical limit, but this doesn’t pose a problem, because the brain reuses unused neurons and is able to grow new synapses. A more interesting question is: How much information can be readily accessed by the brain? Use it or lose it.