Your brain changes based on what you did two weeks ago | Hacker News Reader

Your brain changes based on what you did two weeks ago

newsweek.com

98 pointsthunderbong18 comments

I've never been a fan of this "your brain changes" terminology that news outlets are so fond of, as if a mere change in your brain is somehow meaningful.

Obviously, everything you think or experience changes your brain in some way.

It's like saying that opening a new browser window changes your screen. Duh! That's the point of a monitor. Its pixels have to change in order for it to work. Change is a necessary part of how any machine works. The only brain that doesn't change in response to stimuli is a dead brain.

(This isn't to say that all changes in the brain are equally mundane. Many changes are interesting and meaningful! But the simple presence of change is a low enough bar as to be meaningless.)

I agree. The study seems keen to point out that there are various cycles of the brain with various lengths. They claim to have identified a 2-week cycle. It seems likely the brain has all kinds of cycles at geometric-sequence varying frequencies. A ~100hz cycle for updating your vision. A ~20khz cycle for detecting sound pressure changes. A 90 minute sleep cycle. And now apparently, a weeklong cycle and a 15-day cycle. A bad sleep on Sunday night might dampen my whole week if I don't get a chance to make up. A paycheck only comes once every 2 weeks. My brain is a bit different a few days before receiving a check than a few days after. The rest of the article seems to be advice about "maintain healthy habits so they stick" which is nothing new.

Additionally I am bothered by the insistence of these outlets to forego connecting the brain and the mind, as well as hormones and feelings.

Like cortisol and dopamine or whatever are just chemical representations of feelings, are they not? And large areas of the brain are just a physical representation of the mind, right?

It's like they pretend the brain is just some other organ, like our liver or kneecap, and not the irreducable self.

Maybe that's relatable too

The underlying study: https://doi.org/10.1371/journal.pbio.3002797

I’m sure the study is interesting and informing, but the article’s attempt at wrapping it in a popsci take is just too funny. Imagine if your brain didn’t change based on what you did two weeks ago.

Yeah, the brain changing is another way of saying learning and remembering stuff. I trust the study is more than that.

Interesting study, but it's n=1. Not really enough to make that bold statement in the title.

It's misleading.

if you prefer a more specialized publication than newsweek ...

https://neurosciencenews.com/daily-habit-brain-activty-27811...

Seems like basic "you expected that, didn't you?" sort of findings, although they did verify the absence of a lot of correlations. But it's kind of cool that they can directly measure how much impairment a bad night's sleep causes.

fMRIs can show you, at best, when more or less blood is flowing to a certain part of the brain.

Is that sufficient to make any claims about what the brain is actually doing?

The study's abstract says: "To this end, for a single subject" [...]

So.. we can stop reading here?

Now another group of researchers have the opportunity to apply for a grant and propose new research on N=10

Why bother when N=1 is sufficient to solve P=NP?

Researcher: hey, that's odd ...

HN: N=1. Move along, nothing to see here!

To be fair, they're not exactly wrong. Worth repeating with N=10,100,... until we get a robust conclusion, but as it is, there's not much to go on in this one

Exactly. We're not researchers and many of us will internalize the finding without the proper confidence weighting. I wish reporting and HN had a higher standard for studies linked on the site with higher N and ideally some independent replications.

If the results is really interesting and novel then why aren't others racing to replicate it? Because it is not. Yet we're reporting it here with N=1.

As much as people are harping on the fact that the study is N=1, the reality is that these researchers have 133 scans over 133 consecutive days, which is impressive.

I think naysayers are missing the point that increasing statistical power through repeated measures over long periods of time rather than just increasing N is totally valid. This is honestly probably a better approach than running more participants across fewer scans for an initial longitudinal fMRI study (e.g. I think this is more compelling than if a study were to run 10 people with only weekly scans).

Even if the 133 scans reveal an interesting pattern, it's still an interesting pattern that's only thus far been observed in a single individual. That means it's still not meaningfully generalization, and ought to be studied further before conclusions are published.

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