Solid evidence that kids with autism spectrum disorders (ASD) process sensory information such as sound, touch and vision differently than typically developing children has been unearthed by scientists.
The study by researchers at Albert Einstein College of Medicine of Yeshiva University supports decades of clinical and anecdotal observations that individuals with ASD have difficulty coping with multiple sources of sensory information.
The Einstein finding offers new insights into autism and could lead to objective measures for evaluating the effectiveness of autism therapies.
"One of the classic presentations of autism is the child in the corner with his hands over his ears rocking back and forth trying to block out the environment. People have long theorized that these children might not be integrating information across the senses very well. If you have all these sights and sounds coming at you but you can't put them together in a meaningful way, the world can be an overwhelming place," said senior author Dr. Sophie Molholm.
Over the last few years, Molholm and her colleagues have been refining methods for measuring multisensory integration (MSI) using brainwave electroencephalogram (EEG) recordings.
In the current study, MSI was measured in 17 ASD children, ages 6 to 16, and 17 typically developing children matched for age and non-verbal IQ.
The children watched a silent video of their choice while they were presented with unrelated sounds and vibrations.
The auditory and vibrational stimuli were presented separately (creating so-called unisensory conditions) and then together (multisensory condition), which acted as the researchers' index of MSI.
The children's EEG responses to the unisensory conditions were summed and compared to their EEG responses to multisensory conditions.
The responses of the typically developing children to the multisensory stimuli exceeded the sum of their responses to the unisensory stimuli-an indication of healthy MSI, according to the researchers.
On the other hand, in the ASD children, the differences between the sum of children's unisensory responses and their MSI responses were not nearly as pronounced, indicating that these kids were not integrating multisensory information as effectively.
"Our data makes a compelling case, at least for these conditions, that there are differences in multisensory integration between the two groups," said Molholm.
The study appears in the latest online issue of Autism Research.