I think your expertise would be very welcome, but this comment is entirely unhelpful as-is. Saying there are bad comments in this thread and also that there is good literature out there without providing any specifics at all is just noise.
You don't have to respond to every comment you see to contribute to the discussion. At minimum, could you provide a hint for some literature you suggest reading?
Nah, it's not noise. It's a useful reminder not to take any comments too seriously and that this topic is far outside the average commenter's expertise.
I say this as a psychologist who is advising you to ignore all claims to the contrary, because they are misinformed. It is clear from the literature.
Yes, it factually is, because...
> It's a useful reminder not to take any comments too seriously
...this is factually incorrect, because GP comment is literally not saying that - it's a specific dunk on a specific subset of critical comments with zero useful information about which comments or bad or why they're bad or any evidence to back up the assertion that they're bad or anything else useful.
(GP did go back and respond to some other comments with specific technical criticisms - after they made this initial comment. The initial comment itself is still highly problematic, as are fallacious praise of it, like this one.)
The literature is huge, and my bias is that I believe most of the only really good fMRI research is methodological research (i.e. about what fMRI actually means, and how to reliably analyze it). Many of the links I've provided here speak to this.
I don't think there is much reliable fMRI research that tells us anything about people, emotions, or cognition, beyond confirming some likely localization of function to the sensory and motor cortices, and some stuff about the Default Mode Network(s) that is of unclear importance.
A lot of the more reliable stuff involves the Human Connectome Project (HCP) fMRI data, since this was done very carefully with a lot of participants, if you want a place to start for actual human-relevant findings. But the field is still really young.
The BOLD signal, the thing measured by fMRI, is a proxy for actual brain activity. The logic is that neural firing requires a lot of energy and so active neurons will being using more oxygen for their metabolism, and this oxygen comes from the blood. Thus, if you measure local changes in the oxygenation of blood, you'll know something about how active nearby neurons are. However, it's an indirect and complicated relationship. The blood flow to an area can itself change, or cells could extract more or less oxygen from the blood--the system itself is usually not running at its limits.
Direct measurements from animals, where you can measure (and manipulate) brain activity while measuring BOLD, have shown how complicated this is. Nikos Logathetis and Ralph Freeman's groups, among many others did a lot of work on this, especially c. 2000-2010. If you're interested, you could check out this news and views on Logathetis's group's 2001 Nature paper [1]. One of the conclusions of their work is that BOLD is influenced by a lot of things but largely measure the inputs to an area and the synchrony within it, rather than just the average firing rate.
In this paper, the researchers adjust the MRI sequences to compare blood oxygenation, oxygen usage, and blood flow and find that these are not perfectly related. This is a nice demonstration, but not a totally unexpected finding either. The argument in the paper is also not "abandon fMRI" but rather that you need to measure and interpret these things carefully.
In short, the whole area of neurovascular coupling is hard--it includes complicated physics (to make measurements), tricky chemistry, and messy biology, all in a system full of complicated dynamics and feedback.
Condolences.
It's why I generally only ask questions, or ask for clarification instead of directly challenging something I think might be wrong now in threads that aren't related to something I have deeeeep personal knowledge of. I know when I'm out of my area, and don't want to add to the ignorance.
Being all "PC" and "nice" about stuff that is what it is, or isn't -- THAT adds to ignorance.
Or worse, your whole field can be insitutionally blind to its own failings and randoms outside of it actually DO know more than you!. Chiropractors are literally worthless and being told "oh you don't get it bro" by them is their cope for being scammers, not an example of "their Gell Mann amnesia"
Instead of a nothingburger, you could have used your academic prowess to break down the top 1/2 misconceptions with expertise.
You might not have time to respond to all the comments but a couple of clarifications could have helped anyone else who doesn't comment without experience.
Just saying that next time you can be the change you want to see in HN instead of wasting text telling us how ignorant we are.
I don't think there would be much clear guidance for them on how to interpret any such fMRI abnormality on its own, but it might still be something useful for further investigations, and this might especially be the case for surgery. It might also have been done as part of research, if you consented to anything like that?
I am NOT an expert on fMRI in medical contexts, but you can surely get a rough idea of the potential value of fMRI with a quick search: https://scholar.google.ca/scholar?q=fMRI+surgery+brain&hl=en...
Thanks for the link, useful to read.