It is a common theory that the overwhelming sensory stimulation that comes with autism inhibits other brain activity. Researchers from Vanderbilt University and the University of Rochester decided to test this concept. Their findings were published this month in The Journal of Neuroscience.
The study worked with 46 children—20 had autism and 26 were neurotypical. The researchers showed groups short video clips that involved moving black and white vertical bars of three different sizes. The participants, kids aged 8 to 17, had to determine if the bars were moving to the left or to the right. This experiment was conducted two times, with high-contrast and low-contrast images respectively.
The researchers expected that the autistic group would do better with the high-contrast bars because they would probably be less inhibited by spatial suppression, which makes it hard for observers to detect motion while objects are growing in size. As it happens, the autistic group did do much better than the control group with the high-contrast images, but it was not because of spatial suppression. While spatial suppression did make the autistic participants slower at recognizing motion, they still did so twice as fast as the control group.
Jennifer Foss-Feig, one of the co-authors of the study, commented of the results, “That was really surprising. People have not found this enhanced motion perception before.” She also explained that while the study did not prove exactly what they expected it would, the findings probably have broader implications for the field. “The thought is that sensory systems develop very early on and if you have differences or deficits in terms of the way your brain is responding to sensory input, that would have real cascading effects developmentally,” Foss-Feig said.
This also fits with the comments from study co-author, Duje Tadin, who explained that one way to conceptualize autism is as a condition where “the balance between different brain processes is impaired,” and “that imbalance … can also result in enhancements,” such as the one observed in this study.