Others are studying specific aspects of behavior, information processing, and other characteristics to learn precisely how children with autism differ from other people and how these characteristics change over time. The findings may lead to improved strategies for early diagnosis and intervention. Related studies are examining how the cerebellum develops and processes information, how different brain regions function in relation to each other, and how alterations in this relationship during development may result in the signs and symptoms of autism. Researchers hope this research will provide new clues about how autism develops and how brain abnormalities affect behavior. Symptoms usually appear during the first 3 years of childhood and continue throughout life.
Autism varies in severity.
The most severe cases may feature extremely repetitive, unusual, self-injurious, and aggressive behavior. The milder forms may resemble a personality disorder associated with a perceived learning disability. The hallmark of autism is impaired social interaction. Children may fail to respond to their names, avoid looking at other people, and have difficulty interpreting the tone of voice or facial expressions of others. Individuals with autism typically do not respond to others' emotions or watch other people's faces for cues about appropriate behavior.