Autism brain response theory a dead end, study says

December 6, 2016
Credit: Human Brain Project

A new study out today in the journal Cerebral Cortex challenges the hypothesis that nerve cells in the brains of individuals with Autism Spectrum Disorders do not reliably and consistently respond to external stimuli.

"Our findings show there is no measurable variation in how individuals with Autism respond to repeated visual and tactile stimuli," said John Foxe, Ph.D., the chair of the University of Rochester Medical Center Department of Neuroscience and senior author of the study. "Consequently, the concept that the symptoms of Autism may arise from unreliable in response to the senses is in all likelihood a scientific cul-de-sac."

The neuronal unreliability theory, which has gained traction in recent years in the wake of a study published in 2012, is based on the assumption that the brain's response to repetitive stimuli - visual, audio, or touch - should be steady and consistent. According to this theory, the brain's response is not constant in individuals with Autism and, consequently, alters their perception of the physical environment and impairs cognitive and social development.

The theory did not ring true with Foxe and his colleagues, based on their decades of studying the brain activity of children with Autism Spectrum Disorders. Furthermore, the original studies that formed the basis for this hypothesis involved functional MRI experiments which measure changes in the in the brain. While fluctuations in blood flow are important indicators of brain activity, these measures do not precisely correlate to the more rapid electrical activity that occurs in the brain when nerve cells are stimulated.

The new study involved 20 individuals diagnosed with Autism and 20 individuals who served as healthy controls. The participants were fitted with a dense array of electrodes on the surface of their scalp to record brain electrical activity and were then exposed to repeated visual stimuli. No matter how the researchers measured the variability of the responses, in Autism were as stable as those of the controls. To make sure that this wasn't just the case in the visual system, the team also evaluated tactile inputs - repeated touches to the wrists of participants - and, once again, measures of brainwave responses provided no evidence whatsoever of increased response variability in the individuals with Autism.

"The point of this study is not to make the case that there aren't any differences in the way that people with an Autism Spectrum Disorders process touch, sight or sound; research shows clear differences in some cases," said Sophie Molholm, Ph.D., an associate professor of Pediatrics and Neuroscience at the Albert Einstein College of Medicine and co-author of the study. "Rather, it is to say that whatever those differences may be, they likely don't simply arise because the brain responses in Autism are more variable."

The authors contend that, while the study essentially demonstrates negative findings, it represents an important contribution in the field of Autism where much of our understanding of the disease is - to the frustration of patients, families, research, and caregivers alike - long on theory and conjecture but short on solid scientific fact.

"We are extremely grateful to the journal for realizing the value of work that says in essence 'there is nothing to be found here,'" said John Butler, Ph.D., an assistant lecturer at the Dublin Institute of Technology and lead author of the study. "It is just as important to get information out there that questions a major theory in the field as it is to publish work that supports it."

Explore further: New quantitative technique shows microstructural brain alternations in autism spectrum disorder

Related Stories

New quantitative technique shows microstructural brain alternations in autism spectrum disorder

November 16, 2016
A new study found significant changes in white matter pathways in the brains of individuals with autism spectrum disorder (ASD) using a novel technique called Automated Fiber Quantification (AFQ). Evidence of both increases ...

Link discovered between touch of individuals with autism and their social difficulties

September 15, 2016
The sense of touch may play a more crucial role in autism spectrum disorder (ASD) than previously assumed. Doctoral researcher Eliane Deschrijver has published study results showing that individuals with ASD may have difficulties ...

Review assesses published research on brain changes associated with autism

April 21, 2016
A recent review that examined all published studies on anatomical abnormalities in the brains of individuals with Autism Spectrum Disorder found substantial discrepancy throughout the literature regarding the reported presence ...

Study finds visual and tactile processing deficits in schizophrenia

May 10, 2016
A new study out today in the journal Translational Psychiatry sheds further light on the idea that schizophrenia is a sensory disorder and that individuals with the condition are impaired in their ability to process stimuli ...

Youth on the autism spectrum overly sensitive to sensory stimuli have brains that react differently

June 10, 2015
Using functional magnetic resonance imaging, a team of UCLA researchers has shown for the first time that children with autism spectrum disorder (ASD) who are overly sensitive to sensory stimuli have brains that react differently ...

Recommended for you

Late-breaking mutations may play an important role in autism

July 17, 2017
A study of nearly 6,000 families, combining three genetic sequencing technologies, finds that mutations that occur after conception play an important role in autism. A team led by investigators at Boston Children's Hospital ...

Females with autism show greater difficulty with day-to-day tasks than male counterparts

July 14, 2017
Women and girls with autism may face greater challenges with real world planning, organization and other daily living skills, according to a study published in the journal Autism Research.

Researchers investigate possible link between carnitine deficiency and autism

July 13, 2017
Researchers are always looking for new clues to the causes of autism, with special emphasis on prevention or treatment. At Baylor College of Medicine, Dr. Arthur Beaudet has been following clinical and genetic clues in patients ...

How children look at mom's face is influenced by genetic factors and altered in autism

July 12, 2017
New research has uncovered compelling evidence that genetics plays a major role in how children look at the world and whether they have a preference for gazing at people's eyes and faces or at objects.

Oxytocin improves social abilities in some kids with autism, study finds

July 10, 2017
Children with autism showed improved social behavior when treated with oxytocin, a hormone linked to social abilities, according to a new study by researchers at the Stanford University School of Medicine. Children with low ...

Possible early diagnosis of autism spectrum disorder

June 29, 2017
Measuring a set of proteins in the blood may enable earlier diagnosis of autism spectrum disorder (ASD), according to a study from the Peter O'Donnell Jr. Brain Institute at UT Southwestern Medical Center.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.