In spite of significant innovations recently made through autism research, a definitive cause for the disorder is still relatively unknown. What exactly a person with autism experiences on a daily basis also remains a bit of a mystery. But a study out of the Vanderbilt Brain Institute compared having an autism spectrum disorder to watching a poorly dubbed, foreign movie when it becomes hard to combine what is seen and what is heard.
"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," Director of the Vanderbilt Brain Institute, Dr. Mark Wallace, said in a press release. "If we can fix this deficit in early sensory function, then maybe we can see benefits in language and communication and social interactions."
Dr. Wallace and his colleagues from the institute compared 32 healthy children between the ages of 6 and 18 against 32 children with some type of autism spectrum disorder. Researchers matched each child’s physical and mental health condition, including their IQ, and exposed them to a series of tests. Participants were asked to observe a series of audiovisual, environmental, and speech stimuli such as flashes, beeps, and a hammer hitting a nail.
After asking the children if any visual and auditory events happened simultaneously, the research team noted an enlarged temporal binding window (TBW) in children with autism. Children with an enlarged TBW tend to struggle with linking visual and auditory events. Under the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, (DSM-5), sensory processing has been listed as core deficit in autism. Approximately 25 percent of children with autism are considered nonverbal.
"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 Dr. Stephen Camarata, professor of hearing and speech sciences. "It is like they are watching a foreign movie that was badly dubbed, the auditory and visual signals do not match in their brains."
According to the Centers for Disease Control and Prevention, one out of every 88 children in the United States is affected by an autism spectrum disorder. People with autism usually experience significant language delays, exhibit unusual behavior and interests, and lack communication and social skills. Symptoms of autism begin at around the age of 3 and persist throughout life, although some can improve throughout the person’s lifetime.
"One of the classic pictures of children with autism is they have their hands over their ears," Dr. Wallace added. "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."