Is there a simple parameter that controls human working memory capacity, which has been set tragically low?

post by Liron · 2019-08-23T22:10:40.154Z · score: 16 (7 votes) · LW · GW · 3 comments

This is a question post.


    3 Vakus Drake
    2 Liron

Here's the kind of thing I mean by "human working memory capacity" being "set tragically low": A 100-word sentence introducing a new concept is often annoyingly hard to wrap one's head around, compared to a longer and more "gentle" explanation.

The concept of working memory seems like a useful reduction of part of what makes intelligence work:

Most of us here think human intelligence can one day be increased a lot, because there doesn't seem to be a fundamental limit to intelligence located anywhere near human-level, but that's a non-constructive reductio type of argument.

On the other hand, it seems like there's an obvious constructive argument to why working memory should be able to be increased: Take whatever set of structures encode the current short-term brain's working memory contents, and analyze how big they are, like how many copies of some lower-level storage unit they have, and imagine architecting the brain to have more such copies of those systems encoding more memory contents.

Getting back to my question...

We all wish we were smarter, but we suspect that there are no easily-tweakable parameters that would yield a big increase in intelligence, or natural selection would have already tweaked them.

But doesn't it feel like working memory is an easily-tweakable parameter, and natural selection just didn't tweak it because it was good enough relative to the rest of the brain and the needs of the species, but it could actually be tweaked pretty easily in a couple thousand generations if there were the selection pressure to do it?

The reason it might make sense to say our small working memories are particularly tragic is if there is, as I suspect, a smaller counterfactual distance to them being larger and much more useful for modern life.


answer by Vakus Drake · 2019-08-27T02:27:39.601Z · score: 3 (2 votes) · LW(p) · GW(p)

It's worth noting here that human working memory is probably vastly worse than our ancestors in many regards, because chimps outperform us on short memory tests by a massive margin. This is probably because hominids repurposed the relevant hardware towards doing other things.

answer by Liron · 2020-01-06T14:22:23.432Z · score: 2 (1 votes) · LW(p) · GW(p)

Wow as Vakus Drake said, looks like chimps have more working memory than us, at least in one sense that feels important:

comment by NaiveTortoise (An1lam) · 2020-01-06T15:50:14.570Z · score: 1 (1 votes) · LW(p) · GW(p)

So, I managed to find what I think is the original study from which this video came and I'm skeptical that it's strong evidence for chimps' working memory exceeding humans'. It does seem like decent evidence for chimp response time being better.

First of all, they picked the best two chimps to compare against humans:

We compared Ai, the best mother performer, Ayumu, the best young performer, and human subjects (n = 9, all university students) in this task.

Second, if I'm reading it correctly, the chimps got more trials in the experiment and had practiced a very similar activity previously.

Each chimpanzee received 10 sessions and each of 9 humans received a single test session.

A ‘masking task’ to test memory was introduced at around the time when the young became five years old. In this task, after touching the first numeral, all other numerals were replaced by white squares. The subject had to remember which numeral appeared in which location, and then touch them based on the knowledge of numerical sequence. All five naïve chimpanzees mastered the masking task, just like Ai.

In other words, the chimps had been practicing a less time-restricted form of the memory activity for years (?) before participating in the experiment. While it's possible that practice wouldn't have improved the human scores. that goes against my prior based on the fact that humans can dramatically improve at similar activities such as n-back.

Third, the humans actually did better than one of the two (best performing) monkeys, Ai, and did nearly as well as the best monkey, Ayumu, on the longest hold duration task.

Image alt-text

From my perspective, this provides evidence that slower human response time may have played a role in the worse performance in the shorter hold tasks. The authors even mention that the shortest duration is "is close to the frequency of occurrence of human saccadic eye movement", meaning that a human would only get a flash of the image before it disappeared.

comment by Liron · 2020-01-06T23:39:31.480Z · score: 2 (1 votes) · LW(p) · GW(p)

Hmmm interesting, thanks for posting this! Overall the fact that humans are so much smarter than chimps but still have the same-size tiny-on-any-absolute-scale symbolic working memory seems to support my original claim that this is a tragically sucky situation.

comment by NaiveTortoise (An1lam) · 2020-01-07T01:45:37.474Z · score: 1 (1 votes) · LW(p) · GW(p)

Totally agree!


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comment by Pattern · 2019-08-24T17:56:34.514Z · score: 1 (1 votes) · LW(p) · GW(p)

There may be ways of "expanding one's working memory" or working with it better so it can do more:

A 100-word sentence introducing a new concept is often annoyingly hard to wrap one's head around, compared to a longer and more "gentle" explanation.

Compare the effectiveness of words to pictures, and where one does better than the other.

I can say "any cycle of gears must have an even number of gears" or I can show a picture of three interlocked gears and ask "Can these gears move?".

comment by Liron · 2019-08-25T01:46:33.154Z · score: 2 (1 votes) · LW(p) · GW(p)

Sure, these kinds of tricks help explain how we've done a lot with the working memory we have, but doesn't it feel like a tragically stingy amount?

comment by Pattern · 2019-08-25T16:15:26.792Z · score: 1 (1 votes) · LW(p) · GW(p)

Eh. I'm more fussed about the difficulty of a) holding info in one's head for longer periods, b) absorbing new information, c) updating.

More "Working memory" would be great, but if you can't remember what you worked out, what's the point?