Thread by @garwboy

Ok, the legendary @elisjames asked why he struggles to remember new info in his forties but can still readily recall countless minor details from childhood

I could only really answer this if I'd done a PhD in memory retrieval mechanisms. And I did. So here we go

#BrainStuff

/1

https://twitter.com/elisjames/status/1466170982993960969

As a rule, the memories we acquire during childhood are more impactful, more enduring, than those we acquire later in life. For various reasons.

First and foremost, things are just 'newer' then. The experiences we have, the info we take in, makes a bigger impression

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After all, childhood is the part of our life where we're figuring out how... 'everything' works, in the world around us. So anything we take in then will form the basis of everything we acquire later on. First impressions, and all that.

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Aside: there are quite a few studies that show that age 4 is a particularly important one when it comes to fundamental memory formation and development. The things we learn or that happen to us (good and bad) at that age seem to have particularly long term effects on us

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So anyway, your childhood brain is especially good at retaining stuff. It's got abundant resources for doing so because it hasn't learned a great deal yet, and is growing and forming rapidly, so needs all the new neural connections (the basis of memories) it can get

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But there's a problem here; our childhood brain may absorb as much info as possible, but after a while, that becomes counterproductive. Too many connections in your developing brain can be like too many programmes on a laptop; slows it down, makes the processor struggle.

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That's why, when adolescence hits, our brain sheds a lot of these unused connection; unused neural connections are removed, and the neural resources are diverted to the actually useful ones. It's partly why teens need more sleep; their brains are constantly being overhauled

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But, how do these automatic processes in the brain know which memories are useful and which aren't? Unfortunately, it's not a completely rational process. In most cases, the most important memories are the ones with a decent *emotional* element.

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That's why we rarely remember the stuff we learned for GCSE exams ('objectively' important) but we vividly remember every embarrassing incident or enjoyable experience ('emotionally' important). Our memory arranging systems are old school, so defer to emotion.

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Ultimately, the memories that stay with us longest are the childhood experiences that we'd emotionally invested in, no matter how obscure or irrelevant they may seem objectively

[In football obsessive @elisjames' case, it was the Welsh Triple Crown winning team of 1988]

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@elisjames This also explains the thing where everyone believes the music they listened to during their teens is the best

Adolescence is a time when we're particularly sensitive to emotional and social stimuli. Music provides all that.

bbc.co.uk/teach/bring-th…

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Unfortunately, the human memory system isn't infinite. Our brain takes short cuts. As we age and become more experienced, where possible, we tend to update existing memories, rather than create wholly new ones.

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Human memory is updated and tweaked all the time. It's not a stone tablet or a read-only file, it's way more plastic and flexible than that. That's often a good thing, but when you're trying to take in new, abstract info, it can make it more of an uphill struggle.

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This explains why, as Elis rightly noted on the latest @distantpod, it's a lot easier as a mature adult to learn new things about stuff you *already* care about, than to absorb wholly new info about something you objectively, rationally want to learn.

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@distantpod Learning brand new things as an adult, particularly when it's abstract info, involves overcoming your brain's resistance to doing so. It's effectively saying "I've already GOT a load of stuff in here! Use that before you throw more on the pile"

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@distantpod You know when your parent or partner tells you you can't buy a new book/album/game/etc. because you've already got several and you've still not finished with those? That's sort of the adult memory system's attitude to learning completely new stuff.

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@distantpod Also explains the weird phenomenon of the Reminiscence Bump, where adults over 40 have a weirdly enhanced recall for events from childhood and adolescence

en.wikipedia.org/wiki/Reminisce….

Which is what @elisjames is describing precisely, in a sense.

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@distantpod @elisjames There's a load more stuff about novelty, emotion, context etc. that feeds into all this, but that's a basic rundown of why we struggle to take in wholly new things as an adult while it was child's play as a... child.

So, yeah. That's #BrainStuff

/end

Not sure if this the first time sport and neuroscience have overlapped without it being about concussion, but people seem to really like this thread about the way memory changes as we age

https://twitter.com/garwboy/status/1466172762972692485