Sunday, May 23, 2010

Lost in The Shadows of Autism Research: Does Exclusion of Low Functioning Autistic Subjects Limit Study Results?

Shadows distract autistic kids is the title of an article in the Times of India which reportedly shows that while people can look at the shadow of an object and often figure out what the object is, shadows interfere with how autistic children recognize objects.  The study however involved only high functioning autistic children.  Low functioning autistic children were, once again, excluded.

Notwithstanding the involvement of only High Functioning Autistic subjects the article states with reference to autism generally:

"These new findings shed light on the sensory abnormalities that accompany and possibly even help cause autism, the researchers said ... in autistic children, the presence of shadows — either matching or not matching the objects — interfered with recognition, making them take a little less than 350 milliseconds on average to do either. Instead, they reacted faster when there were no shadows present, recognizing objects in roughly 310 milliseconds. A possible explanation is that in autism, shadows go from being simple features worth a glance to extra details they hyper-focus on, potentially eating up their attention.

Is it possible to draw conclusions about the entire autism spectrum based on studies which exclude low functioning autistic subjects? Personally, I am doubtful.


jonathan said...

you are correct, it isn't. However, a decent researcher will acknowledge the limitations of their work and state that it is limited to high functioning and not necessarily generalizable to lower functioning.

Most research is done with higher functioning due to compliance issues, etc, as I have written before on my blog and your comments section. If there was some way to solve the problem so that lower functioning subjects could be more easily researched, I am sure autism researchers (possibly excluding laurent mottron and michelle dawson and Morton Gernsbacher) would love to hear them. Particularly my friend Matthew Belmonte who does fMRI and EEG research on higher functioning autistics but has a severely autistic brother who can't speak.

Unknown said...

I am not convinced that it is impossible to design studies to include low functioning, intellectually disabled autistic subjects.

Regardless it is not safe to assume that results obtained from studies with HFA subjects can automatically be applied to persons with low functioning autism disorders.

Researchers should be careful in media interviews and stress the study results limitation to HFA.

Ian MacGregor said...

Howard, their is quite a bit of agreement with your position on the lack of research on Low Functioning individuals. From a recent workshop on non-verbal school age children

"General Discussion of Workshop Goals

Very little research over the past couple of decades has directly investigated the nonverbal school-aged child with ASD; almost none have been included in research studies. This has left us with a dearth of knowledge about who these children are, what their underlying skills and impairments are, and how we might be able to provide interventions that support the development of fundamental communication skills."


"There is currently nothing in the literature on this population, which suggests there is a need for a comprehensive review of the state of knowledge (perhaps based on the workshop). This review would summarize what we know about these children, what we do not know, how we can evaluate them, and potentially effective treatments and treatment designs."

The article includes ways of addressing the ptoblem.

The population of non-verbal children and LFA children are not the same, but there is a huge overlap.

Tammy said...

More and more, these studies are being released. They use a small sampling and ignore a huge part of the spectrum. It is truly frustrating.

Kent Adams said...

I'm with Harold that studies could be designed for LFA subjects. I think one of the main issues is being able to design a study that uses humane methods to obtain the data. Matthew Israel has lots of studies on the LFA, despite the links given by Ian. The problem is that these studies use very inhumane methods and then attribute these inhumane methods as acceptable ways to "treat" severely autistic people.

If they could get more software/hardware engineers involved in fMRI technology, they could come up with methods to do an fMRI without the need to sit still or cooperate. The problem as I see it in regards to fMRI is that we have medical researchers trying to solve this problem. They need to recruit some talented computer engineers to solve this issue.