January 15, 2014
Autistic Kids Experience Life As A Badly Dubbed Movie
[ Watch The Video: Senses Of Sight And Sound Separated In Kids With Autism ]
Brett Smith for redOrbit.com - Your Universe OnlineA group of autism researchers from Vanderbilt University have found that children with the condition experience the world as if they are watching a badly-dubbed foreign movie, in which auditory and visual stimuli are out of sync.
According to the team’s report in The Journal of Neuroscience, children with autism spectrum disorders (ASD) have difficulty combining information coming in simultaneously from both their eyes and their ears. The groundbreaking work could pave the way for new approaches to treating the developmental disorder, the researchers said.
“There is a huge amount of effort and energy going into the treatment of children with autism, virtually none of it is based on a strong empirical foundation tied to sensory function,” said study author Mark Wallace, director of the Vanderbilt Brain Institute. “If we can fix this deficit in early sensory function then maybe we can see benefits in language and communication and social interactions.”
To reach their results, the study authors compared 32 normally developing children between the ages of 6 and 18 years old, including 32 high-functioning children with autism. The children were grouped together in nearly every possible way, including IQ.
The participants were asked to perform several different tasks using mostly computer programs. The children were exposed to simple audio-visual stimuli, such as flashes and beeps; more complex stimuli like a hammer hitting a nail; and finally speech stimuli. After each set of stimuli, participants were asked whether the visual and auditory events happened simultaneously.
The researchers found that participants with autism had a magnification of something known as the temporal binding window (TBW), meaning their brains had difficulty connecting visual and auditory events that happen close together.
“Children with autism have difficulty processing simultaneous input from audio and visual channels. That is, they have trouble integrating simultaneous information from their eyes and their ears,” said co-author Stephen Camarata, professor of hearing and speech sciences at Vanderbilt. “It is like they are watching a foreign movie that was badly dubbed, the auditory and visual signals do not match in their brains.”
Another part of the study revealed that children with autism had problems strongly associating audio-visual speech stimuli.
“One of the classic pictures of children with autism is they have their hands over their ears,” Wallace said. “We believe that one reason for this may be that they are trying to compensate for their changes in sensory function by simply looking at one sense at a time. This may be a strategy to minimize the confusion between the senses.”
The Vanderbilt scientists added that the recently-released Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), essentially the bible of psychiatric diagnoses, is the first edition of the manual to acknowledge sensory processing as a core problem in individuals with autism.
A study published in December by the journal Cell revealed a potential link between the symptoms of ASD and changes in the gut bacteria of mice. The research team also found that after the rodents were treated with bacteria from a healthy gut, many of their behavioral abnormalities went away.