This study was recently released regarding lead exposure and it’s cumulative impact on “IQ” in the United States. The impact of it is absolutely staggering, nearly a billion points of IQ wiped out to make engines quieter. There’s a significant chance that might be an under estimate of the impact. In another perspective, this is the cumulative effect of over 20 million people’s brains wiped down to zero. It’s staggering.
I went through quite a few large dementia studies to see if any of them specifically listed the effect of heavy metals as an etiology. Not a single one did. How can something so pervasive, with such a well established link to neurological issues (and specifically dementia!) fail to come up so frequently in etiological discussions? How is it even possible that supposedly rigorous analysis can miss something so obvious?
There are tons of examples like this, of pervasive conditions which are almost never mentioned in etiological discussions of neurological “conditions”. For example, somewhere between 2-10% of all people in the US ever get full karyotype testing in their lifetime. For the past few decades strides have been made to test for trisomy 21 (Down’s), but they only test for that instead of doing the full karyotope. Why is this important? Because trisomy linked and [XYY “syndrome”] have symptom sets completely indistinguishable from many other “psychiatric” conditions. (Also, note the insane sexism between the two articles. They have nearly the same presentation, but the XXX article leans heavy into the “psychiatric” aspect and “low IQ” while the XYY asserts “mostly normal” despite nearly the exact same presentation. Fucking hell.)
We place a lot of faith in science to help us understand the world around us, or at least reach commonality of terms. Unfortunately the way we practice science is so utterly compromised by what we “believe” and what we “want” things to be that it’s been failing us on a pretty primal level with regard to neurological research. It’s this complete cloud that somehow allows us to believe that the most numerous type of cells in the nervous system (glia) are less impactful of cognitive function than neurons. It allows us to believe that “psychiatric” conditions are “neurological” conditions, despite psychiatry being unable to accurately assess what any of these conditions actually are.
I suppose it shouldn’t be a surprise that science has utterly failed so often in this real as it’s just a tool. It’s a tool that is beholden to and limited in functionality by the whims of it’s wielders.
We can improve the tool pretty dramatically by abandoning hypothesis based practice. Hypothesis based practice is the primary injection point for belief, and that belief corrupts the rest of the process from study setup to interpretation of results.
Edit: This has the hamster wheel running, is it a consistent trait in brains to under bias incorrect or “bad” information and over bias “good” or consistent information? Thinking about this constrained to just neuroscience, thirty years ago it looks like general belief held that localized cerebro-cortical activity was the seat of all cognition with the brainstem and cerebellum providing little to no contribution. Localization of really high level cognitive functions are still a pretty commonly held trope, but it looks like most are moving away from this. Twenty years ago it was commonly held that the cerebellum provided no contribution to cognition, and up until recently the brain stem was considered to be a purely reflexive/autonomic body.
It’s odd to me that these lessons derivable from being wrong and why so rarely factor into current/future thought on topics, like humans by default strongly resist negative afferent at all to global social/external constructs. I’m getting a vague ping that there is evidence along this train of thought I need to follow up on.
Edit 2: Probably not super relevant for the main thrust of this post, but this pre-print embodies literally everything I want to complain about regarding neurons and glia.