Slashdot Mirror
Volatility of Human Memory
prostoalex writes "Scientific Americans looks into the human brain, trying to figure out why some events just tend to stick in our memories forever, while the others are gone: "How does a gene "know" when to strengthen a synapse permanently and when to let a fleeting moment fade unrecorded? And how do the proteins encoded by the gene "know" which of thousands of synapses to strengthen? The same questions have implications for understanding fetal brain development, a time when the brain is deciding which synaptic connections to keep and which to discard. In studying that phenomenon, my lab came up with an intriguing solution to one of these mysteries of memory.""
Does this article explain the dupes on /. ??
From the recently noted on slashdot Edge poll What do You believe is true even though you cannot prove it, I remember this bit by Terrence Sejnowski caught my attention (I'm pasting it here cause I can't figure out how to link to that specific part of the page):
Forgot what I was about to type...
... but then -- OOH! Shiny!
When scientists figure out how this process works, we should start a fund to genetically enhance the memories of the Slashdot editors, in order to prevent DUPES
...Dory the fish, who suffered from the same condition as HM in the Scientific Americ...Ameri... umm...
Sorry... have we met?
I remember back to when I was only 2 years old- I had had surgery on ... well, we'll call it a sensitive part of the body.
Now I don't remember the surgery, and I don't remember the antics I pulled at showing nurses why I was in the hospital... but I *do* remember the first time I had to goto the bathroom after surgery.
That memory is so seared into my brain I can even recall I was high enough to look out a window over the cityscape, and that there was a bricked church in the background and the window had blinds (the black slatted ones) on it.
And I remember so much so terribly much pain I don't know how I survived it.
My parents tell me that after that brief moment of screaming I was OK... and I don't remember anything else of that event save for that moment.
And just for comparison (of a little kid) I've had 18 kidney stones... I have a good memory for pain. But that memory makes me cringe and shiver every time I have it.
I hate when that happens.
On another note... when I was 13 years old I was walking around the house for about 20 minutes trying to find the screw driver I just had, where the heck could it have gone, I just ... had ... it ... in ... my ... hand. It was still there and at that point I knew what lay ahead for me in life.
A feeling of having made the same mistake before: Deja Foobar
I've been tracking the periphery of AI for quite a while. Even though directly emulating the human brain is probably not the best solution for artificial intelligence, has this research opened any new doors lately?
... I can erase goatse and tubgirl from my memory.
If we can figure out what proteins need to be expressed to convert short term to long term memory and somehow in the future find some sort of drug that ups the expression of that gene we will still have a problem with what do you do when every memory is a lasting one? Do ou need to know the plate# of every car you drove by on the way home or the order of the commercials when watching Oprah? I think if we mess with the number of long term memories we make we may also lose the selectivity which is so important in making sure the brain isn't cluttered with irrelevant memories and we strengthen only important ones.
Increase the signal to noise ratio of my memory, then w're in business.
I don't know when I realized this, but the human mind is like the internet. everything you could ever want to know is probably in there, but you need google to find it all and every search eventually leads to something sex-related.
"Evil will always triumph because good is dumb." -- Dark Helmet
Sometimes our brains can be tricked into remembering things that did not happen. Elizabeth Loftus had done much research in the area of misinformation effect, which actually has legal repercussions.
"The first time I had sex. The second time I had sex. The third time I had sex. How about the fourth time? And the fifth?"
/. And the second time. And of the course the third. But the fourth? And the fifth? Those I don't remember.
That reminds of me of the first time i lied on
I haven't RTFA but...
How does a synapse know whether to remember something or not... answer - it doesn't. What we remember is only related to what synapses still function, so it something breaks, we don't remember that particular piece of information.
I personally think that the source of all human illness is basically the body forgetting how to maintain itself... critical synapses failing. But what would I know?
prostoalex forgot the apostrophe in "Scientific American's ...".
If evolution teaches us anything (no comments from the Intelligent Design category please) it's that our memory is working just fine. The memories that really stick with us and are the most vivid are the huge mistakes and successes. This is for the sole purpose of helping us deal with future situations by drawing on past experiences. So not being able to remember where your keys are when you're late for work may seem like the product of a faulty memory, the brain is simply full of more pragmatic information like 'fire burns' or 'never bet on the Steelers'.
A leitmotif the article turns on is the potential programmability, more than the volatility, of human memory. They discuss how the older view of our memory as volatile and mysterious has been refined, as we've discovered the mechanisms for transition between short and long term memory. From the physiological to the cellular level, the idea here is a familiar one -- we know more than ever, and we're learning faster than we had before, in this case about memory and about learning.
Most intriguing are the material implications of the article -- they find memories transitioning to long term storage when information is reinforced at specific intervals and with specific techniques. This matches some experimental evidence as referred to, like the familiar ideas of studying or preparing in the same location you will test or perform in -- but, its level of specificity begs for more experimentation and refinement of memory management techniques. Learning and memory across the whole human experience can be biologically maximized if we find just the right process -- read that slippery section in x minute increments and take 10 minute brakes between 3 repetitions. Or maybe, do asdf to remember x words by rote for the next 4 hours, and do ;lkj to sufficiently remember x for a month. Without running a cord into your ear, the article is promising for its level of detail in exact ways we might approach finding best practices for our current hardware.
I'm curious generally about how soon articles like this, especially up at the Scientific American level of exposure, translate into experiments at universities (and, self-help books?). I'm tempted to modify my own learning accordingly, n/m waiting.
BG
However, there seems to be another difference...
Data on a hard drive, until the hard drive -does- begin to malfunction, is stored perfectly. That is, if I type a paragraph (or an entire book), save it, come back a year later, and reopen that file, then provided that the hard drive is functioning properly, that book will be pulled right back up, word-for-word. While the brain might remember the -idea- of the book, then chances are, if you are asked to repeat, word for word, the third paragraph on page 287, you will not be able to do so, even five minutes after reading it.
Of course, the ability to condense, interpret, and distill the important points out of information is what makes humans superior to computers. But there's something to be said for having a medium (paper and pen, computer, camera, whatever) that can store something exactly, and pull it up to refresh your memory (which likely still has the outline and highlights of important subjects, but may be missing the details) when the need be.
Also, whatever the brain may do, it doesn't always seem to work flawlessly at distinguishing important from unimportant. I have quite a few things pop into my head, at various times, some from when I was as young as 2. These things weren't really important to me even then, and sure in the hell aren't now. But they stay around. Now on the other hand, I'm sure my boss told me to do something, but I just can't remember what it might've been...
To fight the war on terror, stop being afraid.
The protein you're talking about appears to be CREB (I love how 90% of slashdotters feel compelled to post their opinions without reading the f'ing article :) For a good couple of years now, we've known that transgenic fruit flies -- and recently mice, if I'm not mistaken -- engineered to over-express CREB do have strikingly improved memory... but not in the way you think. These flies don't appear to form "more" memories, instead they just learn faster. In other words long-term potentiation seems to happen with less training/effort.
What this means for us humans -- if it means anything at all -- is pretty questionable. However if you want to go out on a limb here, drugs or genetic modifications to increase CREB production could make you learn things faster, without sacrificing that important relevance filter (i.e. remembering every license plate you see or whatever).
Spoken like a Slashdot nerd who has never actually encountered a real woman.
More accurately:
Men forget but never forgive.
Women pretend to forgive but neither forgive nor forget.
Hmmm. This doesn't exactly explain how one can, with crystal clarity, remember absolutely useless bits of information when not being able to retain information that is far more important to ones success in life. For instance, one can forget ones fiance's birthday or the day you got engaged or little things like Valentine's day, while remembering the gram molecular weight of ethanol or the exact number of Tribbles sat on by James T. Kirk.... so I'm not sure that evolution has strictly wired us for efficiency.
The truth is evolution is a coarse brush. In order for something to offer a significant chance of being genetically propagated, it has to offer a sizeable benefit (25%+ if I recall my conversation with one of the world's better population modellers working for CSIRO). Less than that and it will tend to get lost in the noise.
So I'm sure that memory setup the way it has been (to forget some pains, to remember others) has been something we've grown into, but I'm also sure some element of it prevades almost every intelligent animal as well. I bet our cat has that same setup (well, there is the claim they may in fact remember nothing, but I know too well this is just propaganda...). But I wouldn't say the system was yet 'fully optimized' for being able to deal with future events.
The fact is, there probably is no fully optimized configuration, given an infinite range of possible future events. So we're probably in that fuzzy zone of mostly useful in most situations, which is right where we should be (that is to say though I disagree with the particulars of the comment, I agree with the general conclusion).
Sure, we can probably enhance memory via drugs or nanos eventually for certain things. Handy, perhaps an advantage. We may be able to help blot out trauma (a pill, for instance, for a recent victim of physical trauma so the trauma does not become the stuff of recurrent nightmare but fades from their memory over time). So these applications would have some use. But giving everyone an eidetic memory might not be either a good idea nor terribly feasible.
-- Mal: "Well they tell you: never hit a man with a closed fist. But it is, on occasion, hilarious."
This article is a rehash of basic neuronal theory (known for at least a 100 years ago), and slightly less basic information on Long Term Potentiation (which has been known about since the early 70s, although they have been discovering more in recent years); followed by some guesses at how the calcium influx triggers genetic change, because "genetics" is the trendy branch of Biology that is familiar from the cover of Time.
What we don't know is where and how Long Term memories are stored. We know that they are formed through synaptic input in the limbic system. Presumably, they are then passed to somewhere in the cortex. Why? How? Where? That is what we don't know.
BTW, it is quite easy to do your own experiments on LTP. Although they can be a bit dangerous.
Hopefully I didn't put any [] around my words.
I'm not sure we actually lose memories. I count emotions as heuristics based on our memories, ideas that have a lot of information behind them but we can't really backtrace to figure out what is involved. Our emotions are statistical approximations based on ideas and experiences we can no longer afford to keep in conscious memory.
The appeal of the game Go to me is just that. When you've seen your 1000th game you don't remember all the patterns and sequences in all the previous games. You simply can't keep track of which opening moves lead to which outcomes. There are more moves in the game than molecules in a galaxy so it's silly to expect full recognition. What you do get though is how you felt about certain moves as you saw them. You learned to enjoy the quick attack at the opponent or the slow tactfulness that drew out an opponents mistakes. Read enough Go games and you'll begin to see what an experienced player is feeling as he makes his moves. You'll see it because you'll remember the feeling you got when that kind of move was made before. You won't have at hand a mental reference chart for what was a brutish invasion and what was sly trickery based on the specific pattern of the stones. Instead you'll have an approximation attached to a feeling which makes that move vaguely recognizable even though you've never seen it before.
Computers don't have the capacity for heuristics and pattern recognition that people do which is why a three month Go player can soundly beat any Go computer. People have a complex system of feelings which allow us to index and categorize all the experiences of our lives without ever having to remember those experiences explicitly. Go is deep enough that it will show you how someone's head is connected.
Chess is tricky. Go humbles me.
Direct away from face when opening.
A point of the original article and known from
various studies in neuroscience is that "memory" and "mental activity" can not be fully distinguished from the "architecture" of the nerves themselves. Neurons are connected via synapses on dendrites and connections are being formed and reshaped (new topologies of interconnectness. Thus, as differential activity ensues, differential connectedness and synapse development occurs concomitantly. Some neuronal paths will be selected for, while others will be selected against. Hence, "memories" may be stored as "architecture" as well as by the multiple biochemical pathways modulating the formation and "strength" of different "circuits" that ultimately "add" or "multiply" the effect of the firing patterns on the genetic machinery in the nucleus of the neuron, which are critical to the maintenance of longterm memory. It may be a fundamental mistake to assume that "memories" are individual molecules, even though many molecules ultimately are ultimately involved in their existence.
The article is interesting in that the neuron may in some respects by acting like an antenna, whose cellular/genetic machinery and morphology (architecture of dendrites and synapse topology) are designed to adaptively differentially "tune" for different action potential input/output logic via differential signal strength from relative importance of different connections, different dendrite size, and different numbers of synapses.
Perhaps this may suggest that the path to wisdom is to be found by becoming a much better "listener". Attention to subtle nuance may be far more important than our current political culture admits.
This might also go a long way towards explaining why different species have such different brains, yet brains whose underlying organization is so similar.
Personally, I'd prefer a volatile memory.
There are some good things about a clear memory. Being able to recall things with a minimal amount of effort, and maybe, if it's stubborn, the easy recall of where to find it. Immediate notice of a flaw in a pattern, no matter how miniscule or unnoticeable. Noticing inconsistency in a conversation. Tracking how much money you have left.
However, it does have it's downside.
Ever hear the saying "Someday we'll look back and laugh at this?"
I'm still waiting. I still cringe over every single embarassing memory in the 30-year period that is my life. Those memories, when I recall them, are much too clear, and it feels like it just happened, despite the fact that some of those events had occurred over 20-25 years ago. Sometimes it's so strong, I feel the need to shut down, and lately, it's started to cause nervous reactions; too many things are drawing them up as I work to re-integrate myself into that thing known as "Humanity."
Thankfully, my memory, while vivid, is still selective, and I can find the mercy of forgetfulness. I don't think I could survive a photographic memory with my sanity intact.
It is said that if you recalled every single thing, it would take a strong will not to go mad. I believe it.
The Penguin Producer
It's interesting to read the point of view of others. That generally is the way for us to form opinions, and, well, I have my own opinion formed.
I think it's probably not so much a matter of "strengthening" a synapse to remember more clearly. I think it's more of an associative memory thing. As we all know, remembering certain things are "triggered" by events, occurences and coincidences. Certain things could be remembered during a conversation on a certain topic, for example; haven't we all played that game where someone says how bad a fall they took from their bike when that someone was young, and then we go on to say "Well, check out the fall I took..." and then go on to tell them an even worse fall? I think it's things we see, hear, taste, smell, touch, that trigger these memories into surfacing.
Part of this is associative, and we all do it. But, some events are almost omnipresent in our minds. For example, a rape victim. The victim will remember this event on the premise that so many times she's heard about how bad that could be, how intolerable a behaviour that could be for a human, and we get it drilled in our minds. When the event actually happens to her, it will trigger all these memories of hearing how bad it is all at once.
The reverse will then happen: anytime a rape victim will see a commercial on rape prevention, or a attempted rape scene in a movie, that will in turn trigger all these times that she was told that rape is bad, and the event itself. (Keep in mind here, I'm in no way saying rape is just an "event" - I do NOT condone it. We're just not discussing the moral implications here.)
Associations are made between memories and, in turn, synapses, because of all the possible interconnections they have. Based on all the similarities or closeness of incidents in our lives, we re-associate events that happen daily to old, pushed-away-to-the-side memories. That's how when you see an old friend you haven't seen in so long can "bring back" so many great memories.. and bad ones as well.
I doubt that certain events are more powerful than others, but I think they might be more potent than some, simply by all these things we associate together.
My 2 cents!
Sébastien Ferland couzin2000@gmail.com freedom | liberté | libertad | freiheit | libertà libertade |
In light of this article, perhaps the following mental discipline may be useful:
Every ten minutes, review the important experiences of the preceding ten minutes. Also review the important events of the preceding couple of ten-minute intervals.
I guess this would be like a 'mental heart-beat', that would serve to keep your mind active and your useful memories intact.
Totally off topic. Smoke another one.
More telling, visiting an elderly friend in hospital, he introduced me to the wife of the patient opposite who had stroke-related dementia. They were immigrants and he had spoken both English and another major "second" language fluently before his disability, but now can only use his birth language, which is a lonely way to exist in an English-speaking hospital.
Even my mother, who had a very slight stroke a couple of years ago, now starts many more conversations about things from her childhood than about the last third of her life in the house where she still lives reasonably independently in a community where she played a very active role for most of those years.
So I felt Sejnowski's idea sounded sensible when I first read it. However I don't see it as being inconsistent with the SciAm article linked here. To form something more permanent in the intracellular matrix around a synapse, most likely you are still going to need to start with some special protein finding its way to that particular synapse.
And we still need a credible story as to how one or several persistently strengthened synapses actually encode one of the countless details we accumulate in a life time in all their contextual detail.
-- Our systemic servants do not good masters make.
Maybe we should try and masturbate a bit while learning, maybe the notion of an exam will become more pleasurable. ;)
... you may well laugh, but I spend many hours of the day rubbing my crotch whilst I'm learning stuff.
Did I just say that out loud? Oh crap.
"So there he is, risen from the dead. Like that fella, E. T." - Father Ted Crilly
This kind of research is slowly undermining the legal fiction of eye witness testimony.
If in order to commit something to long term memory you need to reactivate relevant synapses after an interval measured in minutes, then the reactivation will surely be compromised by whatever rationalisation you have managed to do in the interim.
If I recall correctly, there have been controlled experiments done in which a stooge managed to readily convince witnesses that certain details of an event where quite different to what had actually happened.
-- Our systemic servants do not good masters make.
My project wound down in October. Since then I've been doing documentation and non-programming duties.
./ for a few months, fall in Love or perhaps read Thomas Mann "Magic Mountain".
Yesterday I had to add a line to a file.
A simple unix command that a few months ago I could have spitted out like second nature...
was gone!
I walked aimlessly through the cube-maze string at blank faces trying to remember but I couldn't.
Was that a cat command? set? awk?
I asked some gurus and referred my to the >> command. Than I sat back in front of my white board and gently and swiftly the line emerged from my dry marker.
>echo "my line" >> myFile
Panick receded and was replaced with cautious optimism.
The understand the nature of volatile memory one has to read
- these are not the droids you are looking for -