The inadequacy of contemporary neuropsychology

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[Significant neuropsychological impairment in children with normal MRI results]
[Article in Polish]

Stolarska U, Steczkowska M, Swierczyńska A, Zajac A, Kaciński M.

Klinika Neurologii Dzieciecej, Katedry Neurologii Dzieci i Młodziezy, Uniwersytet Jagielloński Collegium Medicum, Kraków. neupedkr@cm-uj.krakow.pl

Abstract
The aim of the present work was to present significant cognitive impairment in 7 children with normal neuroimaging and electroencefalography results. In 6 children we observed difficulties in verbal auditory learning, in 3 visual memory impairment, and in 1 a disorder of visuo-spatial analysis and synthesis abilities. The clinical examinations performed during the diagnostic process (MRI, CT, Eeg) revealed no neurobiological correlates of the observed neuropsychological impairment. The authors used the cases described to remind, that even though current neuroimaging techniques seem excitingly promising in the diagnostic process, psychological and neuropsychological assessment remains the most sensitive method for the measurment and description of cognitive functions.


http://www.ncbi.nlm.nih.gov/pubmed/19205359



If "psychological and neuropsychological assessment" remains the most
"sensitive" method for the measurement and description of cognitive
functions...i'd say we ought to reconsider phrenology.

I think i'm living proof of just how "sensitive" these psychometric
tests are.

That is really interesting. I also had an MRI done when I was a child (because I was in a car accident) that found "no abnormalities". However, I also have serious neuro-psychological abnormalities. I have a very severe non-verbal learning disorder. I wonder why an imaging technique like MRI would not detect any damage in my right hemisphere. How could the damage in people with learning disabilities could is be so subtle, that it is undetectable, when the damage sometimes profoundly affects people’s abilities?

I guess neuroscience really is in its infancy. There is so much we don't know about the how the brain works.

heh heh....just kidding, but here's an appropriately humorous image to match the research article:

Yes, as we don't know the total sum of neurological knowledge we are working towards, we have no idea where we are along the path. It always looks as if we're nearly at the end, with only one or two small details yet to fit in. But then it *always* looks like that. My feeling is that with "mind sciences" in general, we are about on a par with ye ancient scientific worlde that based everything on "Earth, Air, Fire, Water".

It's bad enough that the "experts" can't agree on whether our brain chemistry causes our thoughts or our thoughts cause our brain chemistry. Even worse is that they don't *really* know what thoughts actually are. Oh sure, plenty of wise guys write volumes on their opinions and hypothesis, but then other wise guys come along and point out the flaws in the first guys story.

I'd bet any amount that in 100 years, the current spectrum categorisations, ADHD, etc. will be seen as quaint old fashioned, and as laughably incorrect as phrenology and leeching does to us now. Current practices will appear "strange and unusually cruel", just like those of 100 years (and less!) do to us. If the psychological models do not alleviate our suffering, they are of little use.

http://www.psychologytoday.com/articles ... rew-awards

Astrology, without Natal Charts this is meaningless.

Great topic, Horus!

"How could the damage in people with learning disabilities could is be so subtle, that it is undetectable, when the damage sometimes profoundly affects people’s abilities?"
I take it that you had a structural MRI, which as you probably know is literally a picture of brain anatomy that will show you if there's damage in the form of dead tissue, missing gray matter, abnormally sized or shaped areas, etc. Here's the problem, though: developmental disabilities aren't caused by "damage" of this kind. In typically developing people, the brain starts out fairly undifferentiated across hemispheres and within lobes, and gradually becomes more specialized as the person matures and learns new skills. Nearby areas differentiate and communicate less, while far-flung areas join up into functional networks (for language, for instance), and become more connected. As a result, different areas will activate in children and adults performing the same task at the same level of accuracy.

For some reason, this process doesn't happen normally in developmentally disabled people. The usual networks may not develop as much, and different areas will be recruited to compensate. For instance, dyslexics will use more right hemisphere and frontal areas for reading instead of the usual left hemisphere language network. In some cases, people with developmental disabilities might use a different network altogether; for instance, autistic people use basic visual areas instead of the typical frontal-parietal network to solve matrix reasoning problems of the sort found in IQ tests.

These are functional differences that can be detected by a functional MRI. In some cases there may also be structural differences--for instance, IIRC young autistic children have more gray matter overall than typically developing children--but I would guess this may be the exception rather than the rule. Does this make sense?

BTW, I think the article Horus posted is correct that neuroimaging may not be ready to replace neuropsychology (although I think it'll eventually happen!). I think the article's reason is kind of stupid, because it basically amounts to, "if neuropsychology detects abnormal behavior and neuroimaging doesn't detect anything abnormal, neuropsychology must be right." (Uh, prejudiced much? )

But interpretation really is a problem. Studies comparing different groups will often find that one group shows less activation in a region than another. In some studies, less activation is considered better because it indicates more efficient brain usage, while in other studies, it's taken to mean that the area is less well-developed. In some studies, more activation is considered better because it indicates greater numbers of representations, or better-developed ones, but in other studies, it's taken to indicate less efficient processing or compensatory activity. Which interpretation a study uses seems to depend on a) which group shows the increased/decreased activity and b) the researcher's starting hypothesis about the regions in question. ATM, I don't know of any principled "unified theory" of interpreting brain activation differences, and until we have that, I don't think we can use neuroimaging to detect problems with a person's brain functioning.

My own neuropsychological testing roughly mirrored my own self-assessment, although it rated me a little higher in working memory capacity and distinguishing speech from background noise than my real-life performance would warrant. IMO, it focused a little too much on more cognitive skills (intelligence of various sorts, memory, academic abilities, understanding metaphors, social reasoning) and less on visual-spatial or motor skills, where my actual impairments lie. It did confirm that I'm comparatively weak in these areas, but the testing wasn't sensitive enough to pinpoint exactly which visual-spatial and motor skills were impaired. I was a bit disappointed about that, but it didn't really matter because the neuropsychologist was able to refer me to various clinicians who could help me improve my functioning, which was the main point of getting tested in the first place. I would guess that the accuracy of neuropsych testing depends a lot on a) the skill of the examiner and b) the particular impairments an individual has. That might explain why the testing was roughly accurate for me but totally missed Horus's problems.