Not All Information is Useful
May 14, 2023 7:38 AM   Subscribe

But how does the human brain know where to leave them and when it’s worth recording in painstaking detail? How does it know what to forget? The fact is, as far as your brain is concerned, almost nothing is worth keeping. The first thing we do with most of the information we take in about the world is to forget it. from Faulty Memory Is a Feature, Not a Bug [Nautilus; ungated]
posted by chavenet (22 comments total) 36 users marked this as a favorite
Holmes to Watson, early on:

“You see,” he explained, “I consider that a man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things so that he has a difficulty in laying his hands upon it. Now the skilful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.”
posted by doctornemo at 8:34 AM on May 14 [17 favorites]

I dimly remember a passage in Rex Stout's Nero Wolfe stories where Wolfe argues against Holmes on forgetting, but can't find it.
posted by doctornemo at 8:35 AM on May 14 [5 favorites]

We don’t record the data, we remember what it means. Nobody yet has the first idea of how this is done, and computers do something absolutely different.
posted by Phanx at 8:58 AM on May 14 [16 favorites]

The topic of memory, and the usefulness of perfect recall, are an example of something the old SF writers got way wrong. 1940s and 50s SF supermen often had "eidetic memories."

In the 60s there were actual case studies of people with eidetic memories. It turns out to be a profound handicap in everyday life.
posted by Aardvark Cheeselog at 9:06 AM on May 14 [7 favorites]

Great article. The conflation of imagination's role in both the past and present reminds me of the David Berman line because the world is 33% now and 66% then.

I've especially been interested in what this all means with the way dreaming is tied to memory and PTSD. For instance, it is hypothesized that EMDR (which combines guided visualization and recall with simulated REM) works because it allows the patient to actively embed a particular experience in the less immediate, long-term memory, even tying it to a less triggering set of memories or impressions. In this way, it may 'properly' sort a traumatic experience that has been lodged in the immediate memory, much like Feunes's complete recollections.

In understanding the connection of memory and creativity, I also think of the claim that it is impossible to dream of something entirely novel to the dreamer, that our minds can only recombine and interpret from previous input. I've always kinda bristled at this claim, but it does make sense and kinda scientifically bolsters the concept of something like a collective unconscious. While a sharp mind can intuit many wild possibilities from personal experience, exposure to the rich thoughts and expressions of others through liberal arts is the rocket fuel of creativity and sublime understanding.
posted by es_de_bah at 9:16 AM on May 14 [3 favorites]

OK, but can I explain to my brain that I need to remember the name of the colleague I worked with nine months ago more than I need to remember lyrics to random 80s songs I don't even like?
posted by praemunire at 9:46 AM on May 14 [23 favorites]

This morning I learned (in conversation) that the only thing I remember from Guardians of the Galaxy 2 is "Maybe he was your father but he wasn't your daddy.*" Feature/bug is up for debate depending on your fandoms!

*or something. Bug overall, probably.
posted by pepper bird at 10:20 AM on May 14 [2 favorites]

computers do something absolutely different

Indeed, but they also do some things in ways that illuminate underlying issues to a useful extent.

I've long held the opinion that much of what my brain does is build a model of the world I occupy, the purpose of which is to help me anticipate and avoid things that will kill me.

The world is endlessly detailed, but my world model cannot be if for no other reason than that my brain forms such a physically insignificant part of it. So my world model has to be a heavily compressed representation of the world, and like all the most effective information compression methods, the one my brain uses is lossy.

Lossy compression works by transforming its inputs in such a way as to split it into a base representation that vaguely resembles the input while requiring only tiny amounts of information to represent, plus a sprinkling of artifact-correcting detail that requires rather more. The more accuracy (i.e. less loss) that's required, the heavier that sprinkling needs to be and the less effective the compression.

Lossy compression also involves a tradeoff between the amount of compression that can be achieved and the time required to achieve it. Base representations that are both minimal and usefully accurate even if vague are usually hard to generate.

I think of understandings as minimal vague base representations. And the more widely applicable any given understanding is, the more information it will save when used as a representational base for all of those applications. When a thing "makes sense", that's because some pre-existing vague representation has proved general enough to be a base for compressing it. This is why a good conceptual grasp of e.g. high-school physics is such a useful thing to have.

One of the most interesting things I've experienced lately has been happening on my myotherapist's massage table as she works her painful magic on knots that haven't previously proved accessible, where I suddenly find myself flashing back to specific injuries to the body parts concerned.

The first time this happened, I suddenly found myself re-experiencing this fall in astonishingly vivid detail. Normally I'm almost totally aphantasic, but this flashback came with full visuals as well as sounds, smells, proprioception, balance and time-of-day awareness: it was as if I had suddenly been physically transported out of the treatment room and was falling onto that railing all over again. And as she continued to work my iliotibial band I kept on falling onto the railing, over and over and over again. Flash, flash, flash, flash, flash.

Part of my awareness remained on the massage table between flashes, though: enough to establish a connection between astonishment at smashing onto the rail and astonishment at the fact of flashing back in this way. And as the flashes kept coming, their intensity faded until basically all I had left was an ordinary episodic memory that I was able to give a much more detailed verbal recount of than I'd ever managed before.

I've never suffered anything like PTSD from that fall or the many other injuries whose Replay buttons she's subsequently found socked away in my musculature, but the fully reality-replacing nature of the flashbacks is fully consistent with everything I've ever read about what happens spontaneously to people who do live with PTSD. So I'm quite convinced that this is a mode in which animals lay down memories under conditions of extreme stress: if the world comes at us so fast that we just don't have time to achieve the usual compression and sort out what ought to be kept from what can safely be lost, we store undifferentiated experience like it was video in 8K Raw format rather than 144P H.264 so that at least we can edit and frame and render it properly later.

That's tremendously information-expensive, though. And this could explain why people who've been put through a lot of traumatic experiences find themselves having great difficulty coping with the ordinary business of living: their memories (and imaginations, if the OP is on the right track) are pretty much full because so many episodes are simply not compressed as lossily as they could be, so their world models just don't track their lives well any more.
posted by flabdablet at 10:27 AM on May 14 [26 favorites]

I do like the observation in TFA that basically, memory and imagination are two aspects of the same thing. It's been clear for a long time that our memories are not like recording devices. I think that formation makes it really clear how not like recordings our memories are.
posted by Aardvark Cheeselog at 10:59 AM on May 14 [3 favorites]

OK, but can I explain to my brain that I need to remember the name of the colleague I worked with nine months ago more than I need to remember lyrics to random 80s songs I don't even like?

The trick is to develop an active dislike for your colleague.
posted by cortex at 11:42 AM on May 14 [12 favorites]

Perhaps this explains why Data, in Star Trek: The Next Generation, had such trouble moving toward being human. His perfect memory blocked him from seeing a future in which he was increasingly like his human friends.
posted by bryon at 11:48 AM on May 14 [2 favorites]

In general, I can't remember where I put my keys, but after friend challenged me when I told her I remembered in painstaking detail all the times I'd committed a horrifying faux pas in my life since childhood, I started writing them down. After about 150, I quit.

A big piece of me wants to tell you that this helped, that I was able to forgive myself and move on, but no, still wake up at three am recalling the time I misgendered a barista in 2009 or the time I accidentally insulted one of my classmates in 10th grade or the time I confidently rattled off the wrong date on a sixth grade history quiz and my teacher corrected me or the time or the time or the time . . .

I would really, really love to figure out how to forget things.
posted by thivaia at 12:05 PM on May 14 [13 favorites]

I had an ex who apparently had a memory like a steel trap.
She drank a lot to calm her nerves, I think this constant memory of everything in the smallest detail caused her severe anxiety.
It didn't help that I was heavily drinking at the time and didn't remember shit, and then she would get mad about it.

Anyways. Yes, it's definitely healthy to forget some things.
posted by symbioid at 12:47 PM on May 14 [3 favorites]

Autistic brains do much less of this pruning! A reason that we often get told we miss the forward for the trees is that our brains are so good at obsessive cataloging, and in fact have much more memory space than allistic people. We are very much human and have wonderful imaginations. That other people view our ability to remember things as a bug is … not our problem.
posted by Bottlecap at 2:29 PM on May 14 [9 favorites]

I had kind of always prided myself on my memory, and my ability to remember things. I could recount things that had happened decades ago in vivid detail. Dates, events, I thought they were all right there, including things that thivaia would’ve had on their list. It honestly wasn’t great, because I could remember all of the shitty things I’ve said and done in a lifetime of them. Those weren’t the things I rattled off whenever needed, those were evidence of the terrible person I am and have been, and I would no more let those out than a murderer would wave the murder weapon around the police station.

A couple things have happened, since. One, I’m getting older. I’m on the closer to fifty side of forty, and I can actually feel my memory slipping. It filled me (and still does, sometimes) with panic. What am I, if not the guy who remembers things? I’ve realized I can’t fully rely on my memory anymore. I need to write things down. I have to use a shared calendar with Mrs. Ghidorah because she’s exhausted by answering my repeated questions about what we’re doing this week, or when she’s working.

The other thing was going home to be with my mother while she passed, and spending a full month with my sister, longer than we’ve been together in probably twenty five years or more. Spending time with her, with family, with friends from college, and, most strikingly, finding a shoebox in a storage unit filled with letters I had received from roughly the ages of 14 to 22. I didn’t have a lot of friends in my home town, but I had a lot of friends in other places through youth groups and scifi conventions. Those letters, which I almost threw away before looking at, absolutely sure I didn’t want more proof of how awful I was and continue to be, shocked me. I had no memory of being the person that these people had written these letters to. There were, evidently, a solid handful of people who thought I wasn't just a nice, funny, caring person, but worth writing four, five, sometimes eight letter pages to on a weekly basis (the pre-internet, pre-free phone call world was a different place). Reading through those letters was like finding out about myself all over again. My image of my self as a teen was utterly at odds with what I read, and again and again, letter after letter, it was clear that these people cared deeply about me, that I was, to them, a person worth caring about. It's taking time, and I can't always remember to do it, but I try to keep that in my mind, to keep that as a support for when I start picking at myself, start listing the reasons I'm an awful person. I might think so, but I'm just an aging guy with memory problems, but I've got written proof that I'm wrong.

My family's way of communication is telling stories about the past, and my sister is like a repository of family history. It's a little unfair, in that she's almost six years older than I am, and has that age difference that allowed her to understand and experience things from an older perspective, and able to form a clearer memory of them. Several times while I was home, I'd mention something that happened, and she would counter, saying that the story I was telling wasn't how things had happened at all. More often than not, the little anecdote about my childhood was something that was important enough to me to turn into a story to tell people. These were things that were, in some cases, cornerstones of my world, the firm point I set a lever against, the things that informed my thoughts and actions, and I was being confronted with the fact that I had remembered them utterly wrong. She would go through and show me where I had misremembered, where I had painted myself in an unfair light, or, just as often, portrayed myself as the hero of a story when I'd actually been an unrepentant shit.

It's been about six months since then, and looking back, I can't say that I remember any of those corrections, only that they happened. If I knew any better (and I don't) I imagine my mind has decided, in self-defense, to memory hole all of it, rather than process and accept what it all meant, and means. It's a hell of a thing to find out you've been telling a story wrong for thirty years.
posted by Ghidorah at 4:14 PM on May 14 [13 favorites]

I was part of an eidetic memory study in the 1960s! The study, done at my very progressive grade school, involved a lot of image and reading retention, and got me and one other kid out of a boring class once a week. Its purpose and end results were never made clear.

As a ten-year-old who found school seriously dull, I never studied but aced every test and after a meal out could recite the entire restaurant menu to the amusement of my family. Laugh-In was my favorite program, and I could repeat entire scripts verbatim for my friends.

Every irritation, conflict, personal injury and insult were also recorded, making interpersonal relationships tricky.

When I hit puberty, a switch flipped—I still retained a lot, but it wasn’t the effortless total recall of information that I’d had to that point. This was a huge relief in many ways. My memory continues to be better than many of my contemporaries’ but has become, thankfully, far more selective. Recently I was shocked when approached by an unpleasant person who identified as my co-worker from years ago—I had absolutely no memory of them whatsoever and in fact was grateful for my brain’s apparent ability to edit their memory from my life.
posted by kinnakeet at 4:47 PM on May 14 [8 favorites]

The case of Endel Tulving mentioned in the article sound a lot like Severely Deficient Autobiographical Memory:
Recollection of previously experienced events is a key element of human memory that entails recovery of spatial, perceptual, and mental state details. While deficits in this capacity in association with brain disease have serious functional consequences, little is known about individual differences in autobiographical memory (AM) in healthy individuals. Recently, healthy adults with highly superior autobiographical capacities have been identified (e.g., LePort, A.K., Mattfeld, A.T., Dickinson-Anson, H., Fallon, J.H., Stark, C.E., Kruggel, F., McGaugh, J.L., 2012. Behavioral and neuroanatomical investigation of Highly Superior Autobiographical Memory (HSAM). Neurobiol. Learn. Mem. 98(1), 78-92. doi: 10.1016/j.nlm.2012.05.002). Here we report data from three healthy, high functioning adults with the reverse pattern: lifelong severely deficient autobiographical memory (SDAM) with otherwise preserved cognitive function. Their self-reported selective inability to vividly recollect personally experienced events from a first-person perspective was corroborated by absence of functional magnetic resonance imaging (fMRI) and event-related potential (ERP) biomarkers associated with naturalistic and laboratory episodic recollection, as well as by behavioral evidence of impaired episodic retrieval, particularly for visual information. Yet learning and memory were otherwise intact, as long as these tasks could be accomplished by non-episodic processes. Thus these individuals function normally in day-to-day life, even though their past is experienced in the absence of recollection.
It's often accompanied by aphantasia.
posted by MrVisible at 7:13 PM on May 14 [1 favorite]

I've been through a pattern at a couple jobs as a software developer: (1) I write software to solve a specific problem for a specific client; (2) significant time passes; (3) a potential client comes along, and in preparation for a pitch somebody on the "client success" team (or whatever the particular company called it) asks me how I did the thing for the first client. At that point I have to admit that I no longer remember what I did the first time.

I started to tell the people on that team that working as a programmer means being a professional forgetter. You have to remember a lot of details about something for a short to medium term in order to finish writing the code you're working on, but when you're done you have a new problem to solve with a bunch of new details to remember so you learn how to let it all just go away. The article refers to medium term memory and I have to assume they're talking about the same thing I am.

What I found, though, is that the stuff you shove into your medium term memory as a programmer, that you replace with other stuff and even more stuff after that just as a matter of doing your job, often isn't completely erased. I couldn't remember it on the spot, but if I had pointers like an old email chain forwarded to me, or if I could go look at part of the code I wrote, I could remember how the rest of it all came together with high enough accuracy to do the same sort of thing again pretty quickly.

Personally I'm bad at short term memory beyond simple things like phone numbers, and almost anything can dislodge something like that I need to remember for longer than a few seconds. It drives my wife insane because she tends to try to stack instructions on me (or read restaurant menus at me while I'm not actually able to look at the menu and retain anything), and by the time she finishes I've forgotten everything. My medium term memory is good as long as I don't lose focus, but context switches kill me. My long term memory is leaky but decent with the right prompts. But I also think of that weird sort of programmer memory where stuff is gone but also maybe not as being like an archive with a terrible index. Given enough of a pattern my brain can find the rest of a memory somewhere, but what I don't have is a great way to recall the details from an arbitrarily small reference. I wonder what the scientists would make of that.
posted by fedward at 7:37 PM on May 14 [7 favorites]

I wonder what the scientists would make of that.

It sounds like computer-assisted memory... the kind where you remember where you read an article, not the whole content of the article, so if you need to remember the rest you can go back and search the archives for it.
posted by subdee at 5:26 AM on May 15 [1 favorite]

We don’t record the data, we remember what it means. Nobody yet has the first idea of how this is done, and computers do something absolutely different.

I agree, and would add that emotions try to protect us from things associated with bad memories, which makes sense in evolution, but creates chaos in social settings. Most negative emotions relate to fear in some way. One could argue that positive emotions alleviate fear, especially hope. A consideration about developing AI is that it didn't evolve to fear things the way humans do and doesn't react accordingly. This can't be said about God, whose emotions are both human and represent the random violence of nature.
posted by Brian B. at 7:28 AM on May 15

@fedward I identify strongly with the experiences you mention.

I recently had the experience of getting an assignment to do a thing(1), getting started on the thing (spent most a day on it) before finding out that I already did the thing back in December, and utterly forgot about it.

I too start forgetting the first items on my honey-do lists before I have heard the end of the request.

(1) Specifically, to provide a SQL stored procedure with upsert semantics to maintain a collection of tables (the sproc has several tabletype parameters, for a parent record with children).
posted by Aardvark Cheeselog at 7:30 AM on May 15 [1 favorite]

@thrivaia, I feel you on that one. Blech! It's always such a nasty, fresh jolt of "yikes!" when something brings up one of those memories. And yet, I have a lot of trouble recalling more neutral or even pleasant memories. So rude, brain, so rude!

Not sure there's a better remedy for that than trying to slow down and pay attention when something good is happening. Dunno if there's a good fix for when the bad memories or cringe moments from the past try to reach up out of your brain and bite you.
posted by SaharaRose at 12:51 PM on May 15

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