The difference is that EEG can be used usefully in e.g. biofeedback training and the study of sleep phases, so there is in fact enough signal here for it to be broadly useful in some simple cases. It is not clear fMRI has enough signal for anything even as simple as these things though.
Yes, there are a few medical cases where fMRI makes good simple basic sense, and TBI/Concussion sounds immediately like one of those to me. I seem also to recall them being useful in some cases prior to brain surgeries and the like.
This all makes sense because fMRI tracks metabolic activity via oxygenation changes, which is much more clearly and plausibly related to tissue health and recovery. In these cases, it is also most likely being used within-subject (i.e. longitudinally) to make comparisons to baselines, rather than in an attempt to make speculative inferences about the mind using groups of people, and likely is a simple comparison to baseline rather than bespoke statistical analyses relying on questionable assumptions about the BOLD response being related to overly-specific kinds of neural activity.
fMRI can track oxygenation changes, and indirectly where the blood flow is, or isn't, and perhaps some ideas on where to get it.
All to say, this application might not fall in the 40%.
I just find articles like these can't help but feel like they have an agenda to undermine something instead of simply acknowledge the kinds of things it is and isn't working for.
There's no doubt these researchers have found something, but the need for sensationalistic headlines is well known in academia as well.
Sometimes it's noticeable where the research is specific in scope, but the findings are more general and broad.
> fMRI's are being used in TBI/Concussion recovery
Interesting. Do you happen to have any more information on this topic? I ask because I was under the impression that concussions are a functional/metabolic injury and not a structural injury, therefore, concussions are not visible on any type of fMRI, CT Scan, etc.. Though, I haven't looked into this topic for almost half a decade, so I imagine things have likely progressed.
Concussions seem to be pretty physiological - first they're a brain bleed, and blood doesn't seem to pump the same as it did before the concussion... resulting in different symptoms.
That might be what you're referring to as functional?
Metabolically, or otherwise, if the brain can't operate, other things in the body such as metabolism would be impacted for sure when it can't oversee and run as it normally can?
While I'm not sure if a concussion directly is visible or not (some have sizeable enough brain bleeds that can be visible), concussions to the extent that they are a change in blood circulation changes and issues, can be visualized on fMRI, etc, where it's not regular, those areas suffer in a brain.
Things luckily have progressed and quite exciting.
Out of convenience, I'll share one I know about (no affiliation) that lay out their therapies and the science behind it as well.
Effectively (I hope I'm getting this accurately) it seems the blood vessels in the brain also have signalling from the blood and oxygen that gets affected which affects things downstream from there.
These guys do an fMRI baseline, have you jump on a bike, fMRI again, see what's not getting blood, and then give you exercises and activites for those regions of the brain. It's pretty interesting.