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apolloartemis

If this were true wouldn’t fMRI machines cause either loss of consciousness or extreme hallucinations?

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I believe in dead salmon, they do.

They cause hallucinations in dead salmon? I find that hard to believe.

Loss of consciousness seems equally unlikely.

True, though an easier mistake to make, I imagine.

https://www.scientificamerican.com/blog/scicurious-brain/ign...

I'm not 100% sure I'd call that a hallucination, but it's close enough and interesting enough that I'm happy to stand corrected.

When improper use of a statistical model generates bogus inferences in generative AI, we call the result a "hallucination"...

It should have been called confabulation, hallucination is not the correct analog, tech bros simply used the first word they thought of and it unfortunately stuck.

Undesirable output might be more accurate, since there is absolutely no difference in the process of creating a useful output vs a “hallucination” other than the utility of the resulting data.

I had a partially formed insight along these lines, that LLMs exist in this latent space of information that has so little external grounding. A sort of deeamspace. I wonder if embodying them in robots will anchor them to some kind of ground-truth source?

I was referring to the dead salmon in the study seeming to show increased activation in the brain and spinal coord.

Thank you for the giggle, I misread this as a statement of faith and a non-sequitur.

I had an fMRI and also believe in dead salmon now, it's a common side effect but it's worth it for the diagnostic data they get.

Yeah, really needed the comma on the left side of the parenthesis.

Not necessarily - I think it works like Daniel Kahneman's System 1 and System 2. Your conscious system is System 2 - when it's not working correctly, you just fall back to System 1.

Independently, since the whole idea relies on resonance, it may be the case that an fMRI doesn't actually interfere with the "stochastic resonance" mechanic quite like TMS (transcranial magnetic simulation) seems to.

If you model the brain this way, dementia looks like a clear breakdown of System 2, which is an interesting thought experiment even if the mechanics aren't perfect: https://1393.xyz/writing/alzheimers-is-the-symptom-not-the-p...

You know the mechanism of TMS is not mysterious. It requires no magnetoreception or "stochastic resonance". It is simply inducing electrical currents to modulate neural activity. Its effects are consistent with the known laws of physics, known properties of neurons, and decades of neuroscience research.

Of course!

But also:

> Although the biology of why TMS works isn't completely understood, the stimulation appears to affect how the brain is working.

https://www.mayoclinic.org/tests-procedures/transcranial-mag...

I think it's reasonable to assume there's room to sharpen our understanding of it quite a bit.

I think you're conflating one question with another. The "why" in question is why altering neural activity in that way results in clinical effects. It is not the "why" TMS alters neural activity.

I appreciate that you feel this way, but the mechanisms behind exactly which neural circuits are activated by TMS are simply not yet fully understood.

From 2024:

> Transcranial magnetic stimulation (TMS) is a non-invasive, FDA-cleared treatment for neuropsychiatric disorders with broad potential for new applications, but the neural circuits that are engaged during TMS are still poorly understood.

[0]https://journals.plos.org/ploscompbiol/article?id=10.1371%2F...

Again, different question. We know, fundamentally, how TMS causes stimulation/suppression of neural activity, and it does not require magnetoreception. Look at it this way: we don't fully understand how SSRI's cure depression, but we do know their primary target and that their mechanism of action is mediated through that primary target.

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