Studying how the brain relinquishes childhood memories | Hacker News Reader

Studying how the brain relinquishes childhood memories

nautil.us

153 pointsjohnny31329 comments

Aside from the changes to the brain hardware, I'd imagine the way in which we construct memories changes to a much higher level of abstraction in early childhood (e.g. building "photographic" memory from a set of concepts around location, lighting and types and condition of objects rather than simply colours and shapes, building our memory of human interaction from a mental model which assumes the other people have motivations and personality traits not just tones of voice etc). So even if some of the information from earlier years is actually preserved, our older brains may not be able to parse it unless it was important enough to reconstruct with a different mental model.

This really interesting and something I never thought of. I've always told people I have a bad memory, but only recently did I realize that just my episodic memory is abysmal; my conceptual memory is quite good. The difference is so stark that I wonder if I simply don't save/parse anything that can't be abstracted well.

Yes, we can only think about problems i.e. ideas/memories which conflict. Once we have improved our explanations of the world sufficiently the conflicts are resolved and old details become unmemorable.

I have a vivid memory of my early childhood. Can tell you where things were, events, even the directions things faced. Conversations, times of day, etc...

I happened to revisit those frequently as a kid. Trying to figure things out. That same process continues to this day.

IMHO, I got lucky as the basic process on all that happened to be viable. As a result, my life is largely one stream of experience going back to toddler age.

One thing that does happen, appears fairly unique to me, is when something new happens, poses a question:

I go into record mode. I seem to capture a lot. If the question resolves, much of that comes rushing back, and the answers click into place.

Unanswered things just percolate, and I revisit them sometimes. That seems to drive the recall of very early events.

One example was me and my parents visiting neighbors. I was little, like 3. Met their kid named cash. Cash was a thing to me, and I remember that question vividly.

Why name a person a thing?

I "recorded" that afternoon, while interacting with cash. Only murky memories after.

Later, at 17, I recalled all that, combined life experience and asked my mom why we went to see thieves.

See, cash took me downstairs to show me all the stuff they had.

Mother dropped her fork, and said they moved that year out of concern.

Now, having an answer, some of that has faded, but the core bits remain.

I think people can recall more when they connect experiences. When we do that, it all gets refreshed.

Life breaks into eras as we wake up, mature. Get lucid.

I was fairly lucid a kid. Not everyone was. We all very widely in how that all happens, all of us eventually arriving at that lucid state, unless we are broken somehow.

Young children deal with memories on perceptual level - images, smells, feelings. Adults deal with memories on a conceptual level - words.

My wife is a clinical psychologist specialized in the treatment of adult survivors of childhood sexual abuse. For her dissertation, she developed a new treatment that takes these memory processes into account, and it is extraordinarily effective.

Adults in this population are often totally unable to articulate and reason about their childhood experiences, acting out emotionally and developing secondary psychological issues. But it turns out they are able communicate and treat terrible deeply held beliefs through art.

It is not my subject area and I can't explain it with justice, but just wanted to point out that your intuition is on the right track.

Could we get a link, perhaps? I'd like it very much to read more about the method.

I try very hard to avoid making myself special in amongst the general case. But, I came here to observe I had verified memories from close to pre-verbal times, something I am told is not common.

If these were subsequent implants from conversation or comment from my elders, it was pretty subtle. The memories are far weaker now, but up to my twenties they were strong, lasting visual impressions of three specific locations.

(I'm in my fifties now)

I believe I remember potty training but my parents said I learned at 13 months. I'm likely misremembering using a tiny plastic toilet in the bathroom from that age to 2-3.

I can almost certainly remember the daunting climb onto a full sized toilet between age 3-4.

I remember waking up in a cot and shaking the bells on my legs deliberately to get my mother’s attention. I had a picture in my mind of my mum responding to the shaking of my leg, I shook my leg and my mother responded in the exact way I thought she would.

I remember the first day I was at kindergarten, I remember distinctly talking with my classmates about our ages. I remember answering I was 2. (2 years 9 months)

Right. Yet we're told there are few retained memories from this time. Maybe what they meant is each of us retain only one or two.. but all of us retain some.

Not sure that's quite right either. I have no recollection of any events before the age of 10 or so.

I am also like this, I basically remember nothing before grades 5/6 and all of my "Memories" are derived from stories told by others.

I think my earliest memory was standing at the door to my basement with one hand on the door knob and the other hand counting, saying something along the lines of "I'm 3 now" or something. Either that or it was some sort of daycare visit. Order is difficult to remember.

As I began typing this I just remembered this football toy chest I used to have in my basement.

The earliest thing I don't remember for which there is (was?) recorded evidence of, is me as a toddler picking up giant carpenter ants and trying to put them in my mouth before a parent came over and stopped me.

Football toy chest! I had one of those. I remember climbing inside it -- being able to fit inside it even. I remember, when I was older, trying to climb inside but backing out because I was afraid of getting stuck in there (and trying to imagine how they would cut me out of the thing, that kind of gives me the heebie jeebies even now).

Lol, yeah, I think everyone that had one of those must have climbed in at some point. Me and my cousins used to put the lid on and roll each other around probably giving us brain damage in the process. I think the last time I got in was after one time when my older cousins were torturing me by sitting on the lid and not letting me out.

I have this memory of the first time I seen a ladies breasts. It was a lady from church who was breastfeeding at our house (it was hippy-ish Vineyard church, there was no hiding it under a blanket). I was somewhere between 3 and 4, so I wasn't that young. But it was a very personal experience, obviously.

What's interesting, to me, is how the memory changed over the years. The colors, and ..um.. shapes have distorted, enlarged, and some details have disappeared completely. It's changed so much that it's probably completely degraded, but it was such a shocking event that I can't forget the memory itself.

Near my work, a heavy gate has fallen on a people. One of my colleagues was a witness and has been asked for his testimony one week latter. There was also a video recording of the events and he was told all the mistakes he has made in his testimony. He was stunned how his memory was so unreliable.

I've been remembering a lot of my childhood lately. Perhaps it's due to recently adding DHEA to my supplement stack, though not exactly sure what the cause is, but it feels good and sad at the same time.

I've wasted a lot of my life due to reasons both within and out of my control.

In any case, one memory that came to mind recently was the ponzi scheme I tried starting around 4th grade -- I think it was? -- when playing around with Print Master Deluxe's fun "ye olde" paper background template. I called it "Joe's Money Club". The point of the club was that people would join and pay dues on a certain schedule, and we'd use those funds to try to make money. I'm joking partly about it being a ponzi scheme ... I think; the story is more fun if I play it up that way, but as I think about it, I don't think it was technically a ponzi scheme, because I do remember trying to sell ear plugs (my dad worked in a factory and had a ton of these packs of orange ear plug pairs). In any case, the club disbanded around a week later due to lack of interest, and I tried to give the money back from dues, but everyone just let me keep it.

wow, this article explains why I don't remember my childhood and the most part of my teenage years, and even later memories are registered as some facts, not actual memories. I always thought it's a protective mechanism my brain developed to get rid of all the negative things, but the authors say it is just the price for being physically active (I run 10k every day, play Ultimate, + martial arts, mountaineering/alpinism and other extreme sports) => growing new neurons:

"A few years back, Frankland and his wife Sheena Josselyn—also a neuroscientist at the Hospital for Sick Children—started to notice that the mice they studied performed worse on certain kinds of memory tests after living in a cage with a running wheel. As the couple knew, exercise on a running wheel promotes neurogenesis—the growth of whole new neurons—in the seahorse-shaped hippocampus, a brain region that is essential for memory. But while neurogenesis in the adult hippocampus likely contributes to the ability to learn and remember, Karl Deisseroth of Stanford University and others had suggested5 that it might also necessitate a certain amount of forgetting. Just as a forest has room for only so many trees, the hippocampus can hold only so many neurons. New brain cells might crowd the territory of other neurons or even replace them altogether, which could in turn break or reconfigure the small circuits that likely store individual memories. Perhaps, then, the especially high rate of neurogenesis in infancy was partly responsible for childhood amnesia."

And this also explains why I always try to schedule my long runs after the calls to my mother (they are stressful), and add more miles if I have more stress in my life in general:

"when adults ran on a hamster wheel after the shocks—thereby stimulating neurogenesis—they started to mirror infants in their forgetfulness. Prozac, which also encourages neural growth, had the same effect. Conversely, when the researchers hindered neurogenesis in infant mice with drugs or genetic engineering, the young animals formed much more stable memories."

My anecdotal observation is that very smart people have few early childhood memories, whereas less smart people have many early childhood memories. Possibly the brains of the smarter people accomplished a more efficient restructuring in which essentially all storage resources became available for adult memories.

If this were true, I wonder if anyone would try to exploit it in contexts such as job interviews. Specifically, could the ELI5 concept be repurposed? Do I ask an applicant to "Explain When You Were 5" and, if they have a coherent response, put that person at the bottom of the pile?

That assumes that "smart" is what you need. What about things like discipline, consistency, honesty, cooperativeness, etc? For example some smart people think that only they are right, and if you task them to do something they don't fully agree with they lose all motivation, even if the "right" in that context is subjective and/or a matter of taste. In some organizations and jobs, the ability to work together as to allow business continuity and redundancy is more valuable than the heroic contributions of any one person. Some smart people also hate unchallenging work, but not all work can be challenging -- indeed a lot of my work as an entrepreneur and supervisor is boring but it is necessary.

You also assume that "smart" has a single definition -- or a good definition at all. What about two different people who are smart in different ways, but only one of those ways is correlated to childhood memories?

What if you are simply observing someone's communication style, and merely interpreting a certain communication style as "less smart"? For example, some people are extraverted and respond really quickly, but on the other hand they didn't really think things through, miss details and change their minds often. Other people could be described as more introverted, don't respond quickly and need to think about something for a couple of nights, but when they come back to you they've really given it a thought and understand all the details and don't change their mind quickly. People in the former group and more easily perceived as "smart" and "a leader" while people in the other less so.

I've seen the definition of IQ. I've studied a bit of psychology. The more I know about those two the more I think that the concept of "IQ" and "smart" are bullshit. There is often no "more/less smart", there is only "different".

I did some meta-learning where I wrote out my thought process while learning and then came back 3 months later to verify retainment as well accuracy.

From doing this I have a few theories about memory (All from my mind. We could record memory different.):

- Memory is read once write many. That is, every time we retrieve a memory we rewrite it back, modifying it slowly.

- The emotional state of the recorded memory combined with the last few recalls determines how easy the memory will automatically pop up, without digging for it. This is based on the emotional state while retrieving the memory. (eg, studying in a class room increases test scores do the environment being the same. Depression, manic depressive, DID, and many other emotional states determine what memories or thoughts will arise in the mind next in relation to the current moment.)

- Memories of just the individual moment (usually slices in time or elements of spacial awareness) are in a sort of tree structure. Details of an event are recursively retrieved while the most important parts to that moment to the individual usually sit higher in the tree. (eg, near photographic memory shows a person who constructs a deep tree, and usually recurses it quickly.)

- The key aspects of a "concept" (a unconscious part of a knowledge instance, not the whole piece) are retained through the distance of neighboring similar concepts (metaphor, or literal), and by how many neighboring concepts there are. This makes a graph. I originally suspected you'd want 3 neighboring concepts, but 2 seems to work perfectly fine for long term memory retainment (if not 1 neighboring node), as long as the neighboring concepts are not too distant. The distance between concepts strongly determines the "pressure" on the mind during learning, the resolution of the knowledge learned, and ultimately if it is retained or not. Oddly, this seems to be somewhat black and white for long term memory: you either retain the concept or you do not, even if that concept is not used, as long as the mind has some level of importance tied to it enough to record it to begin with.

- The finer details of what the patterns the mind processes is a difference between two or more patterns in space and/or time. This functions similar to a video codec where the entire detail is not recorded, but just the relational change. Without this difference between two or more patterns, we may not be able to record anything. (eg, the static on an analog tv. The difference to 'not-static' is recorded, but it is a higher level concept. The individual squares on the screen are not recorded into memory, but instead only the details that can be pattern matched to a neighboring pattern.)

- Neighboring aspects within concepts can and do bridge multiple domains of pattern matching sensory experience, but usually do not unless necessary. I've labeled these axoms and they take longer to learn / more pressure on the mind than normal concepts. (eg, learning addition is more difficult than learning multiplication, because addition crosses from the abstract into the concrete, but multiplication only requires the knowledge of addition to be learned.)

- The name of word that represents a concept can be learned through neighboring word concepts, as it is somewhat like a concept on top of a concept, but I've found the easiest way to remember the name of a thing or the vocabulary word coupled with the concept is to build a story for it. So far I've found two kinds of stories that work best: 1) Humorous metaphors, as humor for some sort of reason creates a strong memory. and 2) An interesting story about it. This could be a mythology, usually a fiction with metaphors to tie it together (see Memory Palace) but for me, my personal interest is etymology: _Why_ is that thing called what it is called? If I have a story for the thought process of why it is called that, the name is recorded. This can be fiction or nonfiction, but I find nonfiction to have the added benefit of understanding the thought process of others or a moment in time, which is a cool added bonus.

- When written down or said out loud during a memory record, it solidifies far better. I have a few theories as to why that is. One of them is akin to 'rubber duck debugging', where writing it out unchunks assumptions and forces one to walk over the entire structure.

- If within a single domain over 220-250 concepts are recorded, either headaches can happen, or old concepts will fall out, much like an LRU. This most likely ties into the size our brain, as that determines how many people we remember (roughly ~250) and the numbers seem to line up here too. By creating categories for subjects this 250 element restriction no longer applies.

This, as mentioned above, is a tree structure being recursed upon and written out in list format, but because there are subtle details beyond these points, I'm probably forgetting a lot that is there in my memory, but I don't have a reason to dive into more detail. (eg, how examples can concrete abstract thoughts solidifying them, ...most etymology for vocabulary is visual, if you go far enough back, ...)

My recall of 300 concepts learned in 3 months is easily above that of 95%. Two years later, with no use of the concepts and retainment is still clearly above 90%, but the etymology of the vocabulary in certain domains (namely logic) seems to fade for me.

I've been considering my mind's data structures as well recently.

I find it, normal?, that humorous metaphors work best. I assume it's easier on the psyche and 'funner' to recall.

Some of the people I know who naturally retain memory the best are some of the brightest and clear headed people. (Not including near perfect memory recording individuals, who do not have humor associated with their memories.)

I on the other hand suck at humor. I find if I try to make a humorous association it seems forced, which does work to some extent, but leaves me feeling a bit forced during recall, so I don't find that worth it. However, when it is naturally funny or amusing, you better believe it sticks.

I suspect this has to do with anxiety. Humor isn't the opposite of anxiety (that would be closer to hypnosis, I would guess) but humor breaks tension like cutting melted butter. So much so, if you get pulled over, and if you can make the officer laugh within a minute, your chances of getting a ticket are nearly zero.

There is clearly something going on here, but what it is, I admit I'm in the dark.

If you're the kind that can find humor in everything, especially puns and similar, you've very lucky.

>Some of the people I know who naturally retain memory the best are some of the brightest and clear headed people. (Not including near perfect memory recording individuals, who do not have humor associated with their memories.) >I on the other hand suck at humor. I find if I try to make a humorous association it seems forced, which does work to some extent, but leaves me feeling a bit forced during recall, so I don't find that worth it. However, when it is naturally funny or amusing, you better believe it sticks.

For me, I find that unless the joke has been expressed to others I simply forget the attempted association. Even if it's a bad joke or bad association, the expression portion helps to make the association of humor with the concept/memory more concrete.

>I suspect this has to do with anxiety. Humor isn't the opposite of anxiety (that would be closer to hypnosis, I would guess) but humor breaks tension like cutting melted butter. So much so, if you get pulled over, and if you can make the officer laugh within a minute, your chances of getting a ticket are nearly zero.

This is a good point. I seem to recall reading somewhere that there a variety of reasons we find things funny but a large one has to do with inhibiting flight/fight response after a close call.

>There is clearly something going on here, but what it is, I admit I'm in the dark.

>If you're the kind that can find humor in everything, especially puns and similar, you've very lucky.

If I take an extreme view (one which I don't fully believe but will use for illustration), then humor of a particular variety helps us to recognize situations that are dangerous/seemingly dangerous, but survivable, if we can recall what decisions extricated us from that situation previously. I feel like that's heading in the direction of creating strong, positive, associations.

Fantastic notes - my intuition agrees with almost all of those.

I think you hit the nail on the head with a name of a word "labeling" an abstraction (ie. "jargon"), which builds upon other abstractions. I drew this out here: https://imgur.com/a/qDEOK

At 38, given, how little I remember about the details of events of last two decades, places I've been, people I met, things I've done... I'm surprised I have any memories of events from my childhood.

What I have been curious about for some time is if there's a neurochemical basis for actively hiding away memories or feelings from your conscious brain, aka compartmentalization.

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