Utilities in America refers to the service relative to ideas of basic needs for survival in the US so they are often public infrastructure with private operators but in the case of some things like the internet, it’s purely privatized.
re: your last point that is not true. we can measure arbitrarially quickly (Nottingham group does some 3d EVI at ~100ms TRs). You can also reduce volumes and just look at single slices etc, a lot of the fundamental research did this (wash U / Minnesota / etc in the 90s). Its just not all that useful because the SNR tanks and the underlying neurovascular response is inherently low-pass. There is a much faster 'initial-dip' where the bold signal swings the other way and crosses zero (from localized accumulation of DeoxyHg before the inrush of OxyHg from the vascular response). Its a lot better correlated with LFP / spiking measures but just very hard to measure on non-research scanners...
Yes, I didn't mention this because you sacrifice so much spatial resolution and/or info doing this that it hardly matters, unless you believe in some very extreme and implausible forms of localization of function. (EDIT: I mean looking at a single slice seems to imply some commitment to localization assumptions; this isn't relevant for reducing spatial resolution.)
For readers who don't know, we can measure at a higher temporal resolution better if we use some tricks, and also massively sacrifice spatial resolution ("reduce volumes") and/or how much of the brain is scanned (look at single slices), but the spatial resolution in most fMRI given e.g. a 0.5 TR (2 images per second) is usually already quite poor (generally already getting difficult to clearly even make out gyri and basic brain anatomy: see for example Figures 7 and on here, noting the TRs in the captions: https://www.frontiersin.org/journals/neuroscience/articles/1...).
Still, it's a good point, and you're right of course newer and better scanners and techniques might improve things here on both fronts, but my understanding is that the magnetic field strengths needed to actually get the right combo of spatial and temporal resolution are, unfortunately, fatal, so we are really up against a physical/biological limit here.
And as you said, it isn't that useful anyway, because the BOLD response is already so slow, and obviously something just emerging from the sum of a massive amount of far more rapid electrochemical signaling that the fMRI just can't measure anyway.
Yes this is ancient news for experts, but, IMO, most fMRI research outside of methodological research is quite practically useless at the moment because of deep measurement issues like these.
So if awareness of this increases the skepticism of papers claiming to have learned things about the brain/mind from fMRI, then I'd say it is a net plus.
agree. especially the comments saying "just address it". Its a lot of technically complicated interactions between the physics, imaging parameters, and processing techniques.
Unfortunately the end users (typically neuroscience/psych grad students in labs with minimal oversight) usually run studies that just "throw everything at the wall and see what sticks" not realizing that is the antithesis of the scientific method. No one goes in to a resting state study saying "we're going to test if the resting state signal in the <region> is <changed somehow> becuase of <underlying physiology>".
They instead measure a bunch of stuff find some regions that pass threshold in a group difference and publish it as "neural correlates of X". Its not science, and its why its not reproducible. People have build whole research programs on noise.
The meaningless NHST ritual is so harmful here. Imagine what we might know by now if all those pointless studies had used their resources to do proper science...
it doesn't measure the oxygen level directly either. the bold signal is correlated to dephasing induced by the oxy/deoxy hg ratio that isn't even necessarially localized to the voxel (flow or long range magnetic susceptibility perturbations from nearby accumulated deoxyhg (veins)).
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