A good memory or a bad one? One brain molecule decides | Hacker News Reader

A good memory or a bad one? One brain molecule decides

quantamagazine.org

93 pointsrbanffy40 comments

My view of the human brain at this point is a massive excel spreadsheet.

Some cells depend on others. Some dont. Change one cell and it usually has an effect on others. Some changes are instantaneous, some takes longer. Some take long enough that you can't figure what caused this effect.

The only difference vs excel is here is we only get to see the cells, and their values, not the formulae behind it. And we are systematically trying to reverse engineer the formulae from the changes we see. We find some patterns, think its a formula, only to later find a contradiction, and that we don't know enough of the formulae yet. In some cases, the contradictions haven't been found just yet.

Theory after theory, change after change.

It seems like this microcosm is akin to the macrocosm of human emotions, memories, psychology etc.

A spreadsheet with probably at least thousands of columns and billions or trillions of rows.

A spreadsheet with a strange search engine.

This morning I was trying to remember the name of an old movie I used to watch when I was a child. I could have easily found it online with a few keywords but I wanted to see how long it'll take for me to remember it organically.

So there I was trying really hard to connect the dots from some fragments of memory up to the movie title. I easily spent 10 minutes to no avail. I gave up. Went to do some chores. And there it was, an hour later, the full title popping in my mind.

Somehow I'm impressed that it kept searching while I was busy doing some other stuff.

Yeah it's fascinating. In my very unscientific mental model for cognition, there's a distinction between "active" and "passive" mental operations. "Active" is anything requiring intention - when you "push" with your mind - like for instance when you are writing code or doing your taxes or building a piece of furniture. It's analytical and requires effort.

"Passive" is when you let your brain solve a problem. For instance when you have that idea in the shower, or think of that movie title when you're folding laundry.

There are problems recalling that distant fact, or the act of creativity which can't be solved actively, and the process of trying to brute force it with effort actually runs counter to reaching a solution.

You can ask your subconscious a question, forget about it, and receive the answer later.

It's really cool.

The brain's way of storing and retrieving information is a absolute mystery. None of the proposed theories are consistent to everyday observations.

So, what's the name of the movie? :)

Ya, cool metaphor. Boids meets reactive programming.

In a book stuffed with ideas, Lingua ex Machina: Reconciling Darwin and Chomsky [2001] had two metaphors that have stuck with me.

There are Darwinian processes within the brain. Like your ear hears some noise, could be interpreted as either "cap" or "cat", those two possibilities fight it out until one wins.

There's a song, some kind of pattern sequence, weaving back and forth, which might be how parts of the brain intracommunicate, which might be how memories are encoded and retrieved (and may also explains why memories are changed by being recalled).

https://www.amazon.com/Lingua-Machina-Reconciling-Darwin-Cho...

I also remain enthralled by the notion that our brains are prediction engines. https://en.wikipedia.org/wiki/On_Intelligence https://www.amazon.com/Thousand-Brains-New-Theory-Intelligen...

I want some kind of synthesis of your spreadsheet and Hawkins' prediction engine metaphors to be true. That'd be cool.

Interesting. I wonder how common miscalibrations are. Personally I've noticed that my overall impression of experiences is usually much more positive than they should be. I'll think back to, say, a business trip I didn't want to take and think of it fondly even though almost every individual memory I have of it I was either bored or miserable.

Checkout the Pollyanna principle [1].

[1] https://en.wikipedia.org/wiki/Pollyanna_principle

I'm not sure there's as much relation as it seems at first. For example, According to the Pollyanna principle, the brain processes information that is pleasing and agreeable in a more precise and exact manner as compared to unpleasant information. is completely the opposite of how it works with me. I have positive general impressions of things about which I can only remember negative details. It's like instead of evaluating the experience based on the sum of its parts I just have an inaccurate header label.

Highly relevant: https://www.smbc-comics.com/comic/2010-10-04

I really enjoyed the next to last panel with the young then old couple. Crazy how a single image can say so many things.

> Personally I've noticed that my overall impression of experiences is usually much more positive than they should be.

I envy you a little bit.

I've noticed that my overall impression of experiences is usually extremely negative, as no matter how many positive memories I have, the negative experiences always overwhelm me so much that the positive ones don't even feel real.

I remember going to a vacation, and while there were a few pleasant moments, I can't really recall them and re-experience them - I just know rationally that they did happen. But recalling unpleasant moments brings all the unpleasantness back to the present moment.

I really wish it was the other way around.

I feel like I take positive experiences as granted and don't feel like they are noteworthy. Negative experiences are something to avoid in the future and I remember them extremely well.

With you on this one.

I started noticing thoughts that were so negative/depressive that I was actually aware of how irrational it was. For example things are actually quite good but my mind is in the dumps. So called Automatic Negative Thoughts (ants).

Since then been trying to reprogram my brain. Force those thoughts out of my head. Start singing randomly. It’s hard and I’m not always successful but I’ve definitely noticed a big improvement overall.

Hopefully this helps you too!

I have been training for almost a decade to flag all experiences as positive. It works; things that were objectively bad (chemo, having covid, getting robbed, business partner stealing money from the company, horrible clients etc) are all positive memories in my head. The only thing that I couldn’t manage was my dogs death; he was mauled to death by a pitbull right in front of me. I used to be quite a negative person and many earlier memories that were not that terrible are all giving me over the top bad feelings: when my grandfather died, I was wallowing so much in negativity that I decided to stop doing that once and for all. It works: live feels very positive and nice even though it of course often is not.

Summary from the abstract with acronyms expanded:

“In sum, we have identified NT (neurotensin) as a neuropeptide that signals valence in the BLA (basolateral amygdala) and showed that NT is a critical neuromodulator that orchestrates positive and negative valence assignment in amygdala neurons by extending valence-specific plasticity to behaviourally relevant timescales.”

Love the artwork for this. Off topic, but when I see art like this I now have to wonder if it was produced through AI-assisted generation

Quanta has the following roles [1], though I wonder how much duplication there is given that several cite "illustration" :

- Art Director

- Graphics Editor

- Visual Designer

Once these AI/ML tools become better, I think a lot of magazines and news orgs will lower their staffing for this role and redeploy the capital to other efforts.

Hopefully existing illustrators can stay on board and work in other creative areas.

[1] https://www.quantamagazine.org/about/

Of course, these AI generation tools are still driven by people who need to learn different techniques for incorporating them with their use of traditional graphics tools.

See this video of someone generating a scene with a photoshop stable diffusion plugin, combined with other photoshop tooling: https://www.reddit.com/r/StableDiffusion/comments/wyduk1/sho...

The art at the top of the article is breathtaking, and looks like it would take a much longer time than writing the article, unless assisted by AI, hence the speculation on my part

I notice AI generated artwork is very good at getting an accurate main subject of the artwork, but seems to lack having small sized details of an image be consistent with the broad message

Things like having a waterfall on the positive side seem very human to me and I doubt it was done by AI

It's credited to Jason Lyon

Since it seems there are multiple Jason Lyons out there, thought it might be good to link directly to their portfolio: https://www.jason-lyon.com/

Related, does this happen to anyone else: you're going about your day, then a random memory comes to you? My theory is something subtle/unconscious makes me remember it (something I saw or felt). I asked my wife if it happens to her, but she said no. Happens to me a few times a week.

I get this semi-frequently, though almost exclusively those with negative emotions attached to them. It has either contributed to, been the cause of, or an effect of (or combination) chronic depression for over half of my life now.

Between medication and some therapy, I'm stable and high functioning, though I feel like I'm always one traumatic experience away from losing it.

I wish I could donate my active brain to science as it feels like there is clearly something not quite well adjusted about it, but alas, I'm still using it (most of the time anyway).

Thank you for sharing. What's odd is usually my memories are kind of banal. I think it's emotional triggered, like how I felt during that stage of my life, but even that's kind of a stretch for me. I'm sweeping my yard, and all of a sudden a memory I had from 20 years ago of me in a subway station comes to me. Maybe it's the heat of the day and the heat of the subway, and their memories are stored close to each other in my neurons and a stray electrical impulse activated it...just wild speculation.

I'm pretty sure this happens to most people. Based on what? Nothing but intuition honestly. Perhaps your wife isn't as interested in metathinking.

The brain (mine anyways) is constantly coming up with new solutions and occasionally recalls irrelevant things in its search for answers...

Yep, happens to me all the time. Since introducing psychedelics into my life I’ve been able to gain more awareness of this and can usually trace things back to what triggered the memory. Like a smell, or a food, music, or a pile of mail/clutter sitting on the counter, an advertisement, etc. I’ve been on a declutter/organization mission lately to help mitigate this. Out of sight, out of mind, as they say.

> Those feelings aren’t just linked to the memory; they are part of it: The brain assigns an emotional “valence” to information as it encodes it, locking in experiences as good or bad memories.

I have doubts about the "locking" part. Many of my memories don't age well: as I revisit them I find that what felt like good memories, in fact weren't.

Sometimes it's because I changed my mind; but often it's because I forced myself to enjoy something I actually didn't care for, and as time passes my willingness to fake enjoyment, fades.

Your memories (and feelings lovked to them) age well. You had to revisit to change that locked feeling, or it would have stayed the same ;)

Exactly, memories aren't immutable, and every visit are bound to have a side effect.

Confusing title. This is talking about a positive or a negative reminiscence, not the faculty of memory.

Funny thing, every time I'm using an umbrella, it seems to be raining! Neuroscience is plagued by poor philosophy of mind, someday it'll do better I hope.

I just feel like brain science is such a shit show that we really need to wait at least 20 years to find out if any of this is really true. Very cool to read about but I feel like we should remain extremely skeptical of everything out of that field

And that molecule is THC

TLDR?

“a small peptide molecule, neurotensin, as the signal that determined whether memories were encoded as positive.”

Thank you!

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