So Called Autism Brain Study Excluded 50% of the Autism Spectrum, Those With Intellectual Disability

Credit (or Discredit) Carnegie Mellon University

What's Wrong With This Picture? It Omits 50% of The Autism Spectrum, Those with Intellectual Disability

The picture above, credit (or discredit) to Carnegie Mellon University,  is from a Science Daily review article  Brain representations of social thoughts accurately predict autism diagnosis which reviews an MRI study published in PLOS ONE, December 2014, Identifying Autism from Neural Representations of Social Interactions: Neurocognitive Markers of Autism,  purporting to demonstrate different brain responses to social interaction stimuli in what are described as "autism" brains as compared to control brains of persons without autism. The review article states that it is based on materials supplied by Carnegie Mellon U the institution that conducted the study in which fMRI imaging was used to compare brain reactions of 17 persons with high functioning autism with the brain reactions of 16 control subjects with similar IQ  levels:

As the father of an almost 19 year old low functioning son with severe autism, profound intellectual disability ... and epilepsy I understand why it may not have been feasible to include intellectually disabled autistic adults in an fMRI study.  What the study authors and the journal articles reviewing the study could have done would have been to describe the results as applying only to those with high functioning autism. After all they expressly and intentionally excluded the 50% of the autism spectrum with intellectually disability (WHO, September 2013) and should have claimed that their results applied only to high functioning autism.  Arguably they could have talked about a "high functioning autism brain" but they certainly can not assume their results apply to the low functioning half of the autism world.  

The study authors should have been more accurate .... and honest ... in what they tell the world about their high functioning autism study.  They could have started with the title of their study and called it:

"Identifying HIGH FUNCTIONING Autism from Neural Representations of Social Interactions: Neurocognitive Markers of HIGH FUNCTIONING Autism".

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]

Catherine Lord, Social Policy Report, Autism Spectrum Disorders Diagnosis, Prevalence, and Services for Children and Families

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.

Autism and fMRI Study: Autism Research Distorted, Once Again, by Exclusion of Low Functioning Autism Subjects

Another fMRI imaging study of brain connectivity in subjects with autism is reported in the Oxford journal Cerebral Cortex, October 12 2010.  I have highlighted  the article, Decreased Interhemispheric Functional Connectivity in Autism, abstract description of the study's autism participants .... all persons with High Functioning Autism.  Once again, the study which puports to draw conclusions about "autism" presumably referring to all of the Pervasive Developmental, or Autism Spectrum Disorders, excludes those most severely affected by autism disorders:

Decreased Interhemispheric Functional Connectivity in Autism

Abstract

The cortical underconnectivity theory asserts that reduced long-range functional connectivity might contribute to a neural mechanism for autism. We examined resting-state blood oxygen level–dependent interhemispheric correlation in 53 males with high-functioning autism and 39 typically developing males from late childhood through early adulthood. By constructing spatial maps of correlation between homologous voxels in each hemisphere, we found significantly reduced interhemispheric correlation specific to regions with functional relevance to autism: sensorimotor cortex, anterior insula, fusiform gyrus, superior temporal gyrus, and superior parietal lobule. Observed interhemispheric connectivity differences were better explained by diagnosis of autism than by potentially confounding neuropsychological metrics of language, IQ, or handedness. Although both corpus callosal volume and gray matter interhemispheric connectivity were significantly reduced in autism, no direct relationship was observed between them, suggesting that structural and functional metrics measure different aspects of interhemispheric connectivity. In the control but not the autism sample, there was decreasing interhemispheric correlation with subject age. Greater differences in interhemispheric correlation were seen for more lateral regions in the brain. These findings suggest that long-range connectivity abnormalities in autism are spatially heterogeneous and that transcallosal connectivity is decreased most in regions with functions associated with behavioral abnormalities in autism. Autism subjects continue to show developmental differences in interhemispheric connectivity into early adulthood.

HealthImaging.com reports on the study in Study: fMRI reveals functional differences in autistic patients and included the study authors' qualifications on the limits of the study including the fact that the study, conclusions, despite the titles of the Cerebral Cortex report and HealthImaging.com article, could not be extended to Low Functioning Autistic patients.

The authors acknowledged that limiting their study to high-functioning young autistic males restricted their findings from being extended to females, younger children or lower-function ASD patients. Nevertheless, Anderson and colleagues emphasized that “Our finding adds to growing evidence that abnormalities of interhemispheric connectivity in autism are widespread but regionally specific and related to cognitive and neurological impairments commonly found in the disorder.”

The authors posited that their findings highlight MRI as a  potential tool to assist physicians in diagnosing and treating autism.

In one breath the study authors acknowledge that the exclusion of low functioning autistic patients restricted their findings from being extended to those patients (or to other excluded groups, including females and younger children). In the next breath though, and in the title of their report and magazine articles the study findings are reported as being applicable to autism generally. 

This is not the first study to exclude low functioning or intellectually disabled autistic subjects from "autism" studies. Prominent autism researcher, and DSM-5 panelist,  Catherine Lord has identified the  tendency to exclude autistic subjects with severe to profound intellectual disabilities:

"However, 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".

The lip service qualifying statement in this recent fMRI study report did not preclude the authors from making generalizations about autism as found across the spectrum notwithstanding the exclusion of low functioning autistic persons from the study. Articles commenting on this and other studies may or may not repeat that qualification.  Most certainly all will be accompanied by headlines reporting new "autism" findings.  Low functioning autistics are routinely excluded from major media institutions that like to focus on the barely affected, very high functioning persons with Aspergers or HFA, the Ari Ne'emans, Alex Planks, JohnMichelle Dawsons and Temple Grandins.  

As in the popular media, so too in "scholarly", "scientific" research. "Autism" just doesn't meant what it use to.

Alleged "autism" spectrum research is anything but representative of the autism "spectrum" disorders.