Investigating Autism

HELSINKI, Finland (Ivanhoe Newswire) -- Autistic children can process simple and complex tones just fine -- it’s sounds associated with human speech that appear to create problems. That’s the finding from a new study out of Finland that measured the ability of autistic and normal children to process different types of sounds.

Autism is a severely debilitating developmental disorder characterized by the inability to relate to people and deficits in oral communication. Autistic children often show remarkable abilities to perceive music. This has lead researchers to wonder if autistic children simply cannot relate to people, or if they just have functional problems with the sounds people make.

The research was conducted among nine high-functioning autistic children and 10 healthy children who served as controls. All underwent brain tests while being assessed for their reactions to acoustically matched simple tones, complex tones, and vowels presented in separate oddball sequences. During the test, the children heard a repetitive standard sound, which was periodically replaced with a different sound. Researchers then measured changes in the children’s brains in response to the deviations.

Results showed the normal children had no problem switching attention between the simple tones, complex tones, and vowel sounds. Autistic children were able to switch attention between the two types of tones, but could not switch to the vowel sounds.

The investigators believe this shows auditory orienting deficits commonly seen among autistic children cannot be adequately explained by sensory deficits alone. Instead, those deficits may be specifically linked to the processing of speech sounds.

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SOURCE: To be published in an upcoming issue of Proceedings of the National Academy of Sciences