A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Fall, 2019 | Number 4, Volume 33

Binocular rivalry may hold clue to early diagnosis

Differences in binocular rivalry may be a marker for autism spectrum disorders (ASD), according to new research by Caroline Robertson and colleagues. 

Binocular rivalry occurs when the eyes see two very different images at the same time. This causes the brain to toggle between perceiving the image seen by the left eye and the image seen by the right eye. 

In earlier research, Robertson and her team showed that people with ASD make this switch between images more slowly than neurotypical individuals. They also demonstrated that this difference is due to reduced action by the inhibitory neurochemical GABA in the visual system of the brain in ASD. 

In the new study, the researchers analyzed participants’ responses to a test of binocular rivalry by measuring brain signals from a single electroencephalography (EEG) electrode placed over the visual region of the brain. The researchers found that based on their data, they could predict whether or not an individual had ASD with 87 percent accuracy. Moreover, participants with more severe symptoms of ASD had a slower rate of binocular rivalry than those with milder symptoms. 

Robertson says, “Autism is hard to screen for in children when the first signs are present. A trained clinician may be able to detect autism at 18 months or even younger, yet the average age of a diagnosis of autism in the U.S. is about four years old. We need objective, non-invasive screening tools that don’t depend on assessing a child’s behavior. One of the big goals of the field is to develop objective neural markers of autism that can work with non-verbal individuals. This neural marker is just that.”


Citations

“Slower binocular rivalry in the autistic brain,” Alina Spiegel, Jeff Mentch, Amanda Haskins, and Caroline Robertson, Current Biology, Vol. 29, September 9, 2019, 2948-2953. Address: [email protected]

—and—

 “Reduced GABAergic action in the autistic brain,” Caroline Robertson, Eva-Maria Ratai, and Nancy Kanwisher, Current Biology, Vol. 26, January 11, 2016, 80.85. Address: [email protected]

—and—

 “New study shows how autism can be measured through a non-verbal marker,” Science Daily, August 15, 2019.