Pathbreaking study by Israeli and American neuroscientists reveals autism's 'noisy' secret

Strapped into a motion-enabled simulator and wearing 3D glasses, 36 adolescent volunteers recently experienced what it was like to "travel" through a field of virtual stars. The experiments provided new and convention-busting data about how sensory stimuli are processed by the brains of individuals with Autism Spectrum Disorder.

The study, entitled "Self-motion perception in autism is compromised by visual noise but integrated optimally across multiple senses," was published online in the Proceedings of the National Academy of Sciences on May 4th, 2015. The authors of the study are Adam Zaidel, of Israel's Bar-Ilan University, and Robin P. Goin-Kochel and Dora E. Angelaki, of Baylor College of Medicine in the United States.

Perceptual Impairment in Autism - a "Noisy" Controversy

One of the hallmarks of Autism Spectrum Disorder (ASD) is superior low-level task performance alongside reduced performance in tasks that involve the processing of complex sensory data. This has led to the assumption that autism is characterized by a difficulty integrating individual units of perceptual data into global concepts. In line with this first assumption, it has further been proposed that individuals with autism have difficulty integrating multi-sensory input.

With its unique experimental set-up, the new study has successfully challenged this conventional wisdom. Moreover, it has identified a neurological phenomenon associated with autism pathology: a heightened sensitivity to "noisy" sensory signals.

"Theories of global and multisensory integration deficits in ASD are deeply rooted in the scientific conversation about autism," says Dr. Adam Zaidel, a member of Bar-Ilan University's Gonda (Goldschmied) Multidisciplinary Brain Research Center, who is the publication's lead author. "Recently, this notion has come under scrutiny, as more and more investigators have observed discrepancies with experimental results."

"In this study we show that heightened sensitivity to sensory noise - the random signals inserted into the visual tasks traditionally used by scientists to test sensory integration levels in autism - may provide an alternative explanation for impaired performance. When this noise is removed from the equation, the integration of visual motion stimuli in ASD is equal to, or maybe even superior to that of the control group. Moreover, our study demonstrates that the multi-sensory integration seen in autistic participants was comparable to that of the non-autistic control group."

Did you know ...

- Autism now affects 1 in 68 children and 1 in 42 boys
- Autism prevalence figures are growing
- Autism is the fastest-growing developmental disorder in the U.S.