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‏إظهار الرسائل ذات التسميات autism brain scan. إظهار كافة الرسائل
‏إظهار الرسائل ذات التسميات autism brain scan. إظهار كافة الرسائل

High Functioning Autism fMRI Brain Scan Study Misrepresented to the Public



"research in ASD has tended to use overwhelmingly White, middle to upper middle class samples, and has often excluded children with multiple disabilities and/or severe to profound intellectual disabilities". [underlining added - HLD]


Yet another fMRI brain scan study, The neural basis of deictic shifting in linguistic perspective-taking in high-functioning autism,  has been published in which Low Functioning, Intellectually Disabled autistic subjects are, by design, excluded  in favor of subjects with High Functioning Autism. This study published in the journal "Brain" by researchers Marcel Just, Akiki Mizuno and their collaborators at CMU's Center for Cognitive Brain Imaging (CCBI) and described in a PR Newswire Release found that errors in choosing a self-referring pronoun (eg. "you" instead of "I") "reflect a disordered neural representation of the self, a function processed by at least two brain areas — one frontal and one posterior". 

As evidenced by the above quote from autism expert Catherine Lord low subjects with low functioning autism, which would include the 80% or persons with Autistic Disorder (DSM-IV) and intellectual disability, are often excluded from autism research.  That exclusion of low functioning, intellectually disabled subjects from  recent  fMRI "autism" brain scan  studies has been even more obvious.  

The Carnegie Mellon researchers should be commended for describing their conclusions, as their study title expressly states,  in terms of High Functioning Autism given that their study subjects were all high functioning autistic persons.   Unfortunately the press release, which identifies Carnegie Mellon as the source of its information,  is not as meticulous and generalizes the study to the entire autism spectrum  in its title and content, including quote from lead research Marcel Joust:

New CMU Brain Imaging Research Reveals Why Autistic Individuals Confuse Pronouns


...


The results revealed a significantly diminished synchronization in autism between a frontal area (the right anterior insula) and a posterior area (precuneus) during pronoun use in the autism group. The participants with autism also were slower and less accurate in their behavioral processing of the pronouns. In particular, the synchronization was lower in autistic participants' brains between the right anterior insula and precuneus when answering a question that contained the pronoun "you," querying something about the participant's view.


"Shifting from one pronoun to another, depending on who the speaker is, constitutes a challenge not just for children with autism but also for adults with high-functioning autism, particularly when referring to one's self," Just said. "The functional collaboration of two brain areas may play a critical role for perspective shifting by supporting an attention shift between oneself and others.


"Pronoun reversals also characterize an atypical understanding of the social world in autism. The ability to flexibly shift viewpoints is vital to social communication, so the autistic impairment affects not just language but social communication," Just added.


...


Ongoing research at the CCBI is assessing the white matter in detail, measuring its integrity and topology, trying to pinpoint the difference in the autistic brain's networks.


"This new understanding of what causes pronoun confusion in autism helps make sense of the larger problems of autism as well as the idiosyncrasies," Just said. "Moreover, it points to new types of therapies that may help rehab the white matter in autism."

Presenting the results of a study of High Functioning Autism subjects as representing all persons with autism, including the low functioning, intellectually disabled excluded from the study is  misrepresentation. It helps promote ignorance, both in the general public about the many intellectually disabled persons with low functioning autistic disorder identified by CDC autism expert Dr. Marshalynn Yeargin-Allsopp as autistic disorder's "vast majority". 

Autism Brain Scan Tests or Just High Functioning Autism Brain Scan Tests?

MSNBC has an article by Amanda Chan on the recent "autism" brain scans Brain scan 'best thing so far' for detecting autism. The article  cautions that the fMRI tests used in a recent study have to be run many times and achieve similar results before the test can be put to clinical  use. The article also does point out that the "autism" subjects in the test were all persons with high functioning autism.  Notwithstanding the cautions expressed the article still  refers to the test results in terms of detecting autism with substantial accuracy  not just high functioning autism.  Given the large numbers of persons with Autistic Disorder who have intellectual disabilities  references to high functioning autistic persons as being representative of autism generally are inaccurate and potentially misleading.

In Study: More Hope for a Brain Scan for Autism Meredith Melnick of TIME also reports on the recent brain scan studies and the same pattern emerges. The use of high functioning autistic subjects only is noted and cautions expressed about the need for more tests.  But once again the article indicates that the study results were able to detect "autism" in a large,  93%, of cases. There is even a reference in the article to "the autistic brain" when describing the results of a recent London MRI study which found that "the test was able to identify the autistic brain with about 90% accuracy."

Influential media sources like MSNBC and TIME are creating a popular view of "autism" as being represented by "high functioning autism".  They are doing so based on a string of research studies which use high functioning autistic subjects and exclude those with low functioning autism. The cautions expressed in such articles are likely to be forgotten as more and more studies of high functioning autistic subjects publish their reports and the excitement builds that a reliable brain scan test has arrived.

Autism disorders are neurological disorders.  Whether and to what extent various genetic and environmental considerations come in to play are matters of great contention. But to my knowledge no one except a few ignorant, cynical comics dispute that autism disorders are neurologically based.  Brain scans do in fact appear to be promising as tests that could distinguish "autism" neurology from others and thereby provide a reliable biologically based diagnostic tool. But only if study participants from all points on the autism spectrum are considered.

Unless low functioning and intellectually disabled subjects are included in the studies used to develop autism brain scan tests such tests could only in honesty be used to detect high functioning autism and could not rule out low functioning autism in any given case.

We should not lose sight of these fundamental truths when developing "autism" brain scan tests.

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