Study co-author Cynthia C. Woo, a project scientist at the University of California, Irvine, said autistic children typically have sensory problems, most common involving smell and touch sensitivity.
The six-month study involved 28 autistic boys, ages 3-12. Researchers placed the boys in two groups based on their age and autism severity, with both groups participating in standard behavioral therapy, but boys in one group also undergoing daily environmental -- sensory-motor -- enrichment exercises.
Parents of each of the 13 boys in the enrichment group received a kit containing essential oil fragrances such as apple, lavender, lemon and vanilla to stimulate sense of smell. For touch, the kit contained squares of plastic doormat, smooth foam, a rubber sink mat, aluminum, fine sandpaper, felt and sponges.
The kit also included pieces of carpet, hard flooring, pillows, cardboard and bubble wrap that parents laid on the floor to create a multi-textured walking path. Items for the children to manipulate included a piggy bank with plastic coins, miniature plastic fruits and a small fishing pole with a magnetic hook.
The researchers instructed parents of children in the enrichment group to conduct two sessions a day -- 15 to 30 minutes total -- of four to seven exercises involving different combinations of sensory stimuli for touch, temperature, sight and movement.
The study, published in Behavioral Neuroscience, found after six months of therapy, 42 percent of the children in the enrichment group significantly improved in behaviors such as relating to people and responding to sights and sounds, compared to 7 percent of the standard group.