MEGAUTISM.JPG

The brains of children with autism produce more static-like "noise" at rest than those of children without the developmental disorder, according to recent CWRU research. The children in the study, who had Asperger's and were between the ages of 6 and 17 years old, had their brains imaged using magnetoencephalography (MEG) shown here, but were lying flat and not looking at images, to approximate brain activity at rest.

(AP Photo/ Joseph Kaczmarek)

CLEVELAND, Ohio -- The brains of children with autism produce significantly more static-like background noise at rest than those of children without the disorder, according to a recent study by Case Western Reserve University researchers. The imaging study also showed evidence of problems with the way different regions of the autistic brain connect to one another and communicate information.

The excess "noise" in the brain may help explain why children with autism have trouble processing sensory information and tend to withdraw from social interactions, said senior author Roberto Fernández Galán, associate professor of neurosciences at CWRU.

Roberto Fernández Galán

“In a sense they are too busy with what’s going on in their own brains,” he said, an interpretation that is very similar to one known as the “intense world” theory of autism, which suggests that autism is a disorder characterized by a hyperactive and overly sensitive brain, rather than a mental deficit.

“We think this is a very nice interpretation of our results,” Galán said. “It basically means that the autistic brain is much more busy at rest.”

The prevalence of autism

spectrum disorders has been increasing dramatically in the United States over the past decade and now affects one in 88 children, according to the Centers for Disease Control and Prevention. While there is no single known cause of autism

,

and a number of

such as parental age and low birth weight contribute to the disorder.

The current study, published in late December in the journal Frontiers in Neuroinformatics, compared the brain activity of nine children with Asperger’s to 10 matched controls with typical brain development. On average, the brains of the kids with Asperger’s produced 42 percent more information at rest than the controls. The children in the study were between the ages of 6 and 17.

The researchers used a non-invasive brain imaging method called magnetoencephalography, or MEG, to measure brain activity. MEG measures the electrical and magnetic fields generated by brain cells, or neurons, when they are active. Information about the sources of the magnetic fields can be determined using mathematical models, and by superimposing MEG images on anatomical images such as MRI, researchers can make conclusions about the brain's structure and function.

Galán is careful to distinguish between brain activity as most of us think of it, however, and the quantifiable “noise” or “information” that his team measured in the brains of the children they studied.

It’s not as simple as saying that an child with autism is always thinking, he said. What their study showed is that neurons activated differently over space and time.

“It’s not telling you anything about what the brain is thinking... but it’s a measure of how complex the activity of the brain is,” Galán said.

He compares the brain to a black box with a simple input and output. The input, in this case, was minimal -- they had the children lying back with nothing to look at -- and the output was measured by the MEG machine.

“We found a very significant difference in autistic children compared to controls," Galán said. “They were creating more information even in the absence of external stimuli.”

'Intense world' theory

The idea of a "noisy" brain in autism is consistent with an emerging and somewhat controversial theory of the disorder called the intense world syndrome, championed by Swiss neuroscientist Henry Makram. First proposed in 2007 in a paper in Frontiers in Neuroscience, Makram described the syndrome as a "hyper-functioning in different brain regions" that causes "hyper-perception, hyper-attention, and hyper-memory" and renders "aspects of the world painfully intense and aversive."

Some in the autism and Asperger's community have responded positively to the idea, saying it explains well their emotional perception of the world and is preferable to the prevailing view of autism as a mental deficit.

Yet others, including many autism researchers and neuroscientists, worry that the proponents' resulting ideas of limiting unexpected stimulation and enrichment as a potential treatment are unwarranted and even dangerous.

"There are definitely aspects of it that make sense and have some scientific support," said Tom Frazier, director of Cleveland Clinic Children's Center for Autism. "It's just what you do with that information from a treatment perspective that's fairly controversial and is sometimes disturbing."

Frazier, who was not involved in Galán’s study, said the current work is a good step forward and should probably be viewed outside the intense world theory.

“It means that the brains of people with autism probably have some background noise going on in addition to having brain regions not communicate well to one another, and that may correlate with some of their sensory issues that they have,” he said. “It also may correlate with some of the special skills that they develop.”

More to study

Galán’s study was small, only included older children, and did not include other children with different developmental disabilities for comparison, all limitations that further research would have to address.

It’s possible, both Galán and Frazier said, that the background noise picked up by the MEG is not unique to autism, and is something that children with most developmental disorders would show. Galán would like to expand his study to adults with schizophrenia as well, he said, given enough funding.

The findings may also be a consequence of years of having a developmental disability and might not be present in infants and toddlers with the disorder, making it much less helpful in diagnosis.

Galán believes that the greatest promise is in using MEG as a biomarker for autism or other neurological disorders in the future.

“I don’t think there is an immediate step forward to develop therapies, but on the other hand it explains a little that the goal should be not only to develop drugs, but on behavioral approaches that help you tame the activity in the brain,” he said.

“Over the last few weeks we've heard from many people with autism who identify with this concept. They say that they just cannot turn off their brains.”