This summer’s 45th Annual Autism Society National Conference in Indianapolis featured keynote speaker Dr. Temple Grandin, noted advocate for autism rights. In her speech, The Autistic Brain, Dr. Grandin recommended a scientific article called “Environmental enrichment as an effective treatment for autism: A randomized controlled trial.” The article, published in the journal Behavioral Neuroscience in 2013, discusses a method of habituating children with autism spectrum disorders to sensory stimuli.
Study authors Woo and Leon of the University of California Irvine hypothesized that increasing an individual’s exposure to sensory experiences could strengthen the ability to cope with and respond to new stimuli. The authors based their hypothesis on studies demonstrating that exposure to environmental stimulation could alleviate neurological “challenges” and disorders for lab animals. Using a kit of materials that engaged the senses, the researchers asked parents to guide their children in sensorimotor activities for six months. The children who completed the program had improved functioning compared to their peers who participated in behavioral therapy throughout the study.
Sensory Issues and Autism: Context
Sensory issues are a component of autism spectrum disorders. The description of autism in the DSM-V includes diagnostic criteria related to sensory sensitivity, listing “Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment” as part of the symptoms (CDC, 2014). More than 90% of children with autism have sensory abnormalities in the form of oversensitivity, unresponsiveness, or sensory-seeking behaviors.
Woo and Leon explain that the senses of smell and touch are among the most common sensory issues for people on the autism spectrum. They state “Not only is sensory processing dysfunction correlated with both maladaptive behaviors and autism severity, but touch and olfactory issues are strong predictors of both atypical social behaviors and poor social communication skills in children with autism.” In short, children with limited sensory processing abilities have more trouble in social situations. Sensitivity and social skills may relate to each other in ways that scientists have not yet quantified.
Why Sensory Enrichment?
The authors chose to focus on sensory enrichment therapy because studies suggest that the sensory environment affects a person’s ability to develop normally. Research in lab animals suggests that the brain “does depend on sensory stimulation for normal development” (Woo & Leon, 2013). Studies demonstrate that sensorimotor experiences can improve the symptoms of conditions like brain trauma, strokes, seizure disorders, schizophrenia, and autism in lab animals.
Other studies suggest that the sensory environment affects humans too. Research demonstrates that a poverty of sensorimotor experiences can damage sensory abilities. In one historical instance, Romanians “sent large numbers of children to orphanages, where they had little environmental stimulation,” report Woo and Leon. These children developed what became known as postinstitutional autistic syndrome. The children had disordered communications, an inability to identify human emotions, and sterotypic behaviors.
Woo and Leon reasoned that if a lack of stimulus could damage the neurological response to stimuli, then an enriched sensory experience could have the opposite effect: strong stimuli could improve sensory abilities.
Engaging the Senses
The study was a randomized controlled trial involving 28 male children aged three to 12 years with a mean age of 6.6 years. All of the children had an autism diagnosis, but the researchers excluded children with forms of autism like Rett’s or Fragile X from the study.
Children who recently started a therapy or medication were not part of the study. The researchers allowed children who had been using their medication for more than three months to participate if the medication was an anticonvulsant. Children on psychotropic medications were not involved in the study. No child undergoing another sensory integration therapy participated in the study, but children taking part in behavioral, speech, or occupational therapy were allowed.
Thirteen of the children completed the sensorimotor enrichment therapy. The remaining 15 children received what the authors call standard care, which included conventional behavioral therapies.
The researchers used four assessments to evaluate the children:
- Autism Diagnostic Observation Scale (ADOS)
- Childhood Autism Rating Scale (CARS)
- Leiter International Performance Scale-Revised (Leiter-R)
- Expressive One-Word Picture Vocabulary Test
At the outset of the study, they assessed the children using the ADOS and the CARS. These tests determined whether the children did, in fact, have an autism spectrum disorder and in which areas their symptoms were strongest. The researchers used the Leiter-R to evaluate the children’s non-verbal cognitive abilities and the Expressive One-Word Picture Vocabulary Test to evaluate verbal intelligence and auditory-visual-verbal association skills.
After the six-month study period, trained psychometricians conducted a second round of evaluations using the same tests. The psychometricians did not know if the children were in the sensorimotor enrichment group or in the standard care group.
Building a Sensorimotor Experience
The researchers created a kit that parents used to help their children to enrich their senses. The kit included:
- Essential oils for olfactory engagement. They selected pleasant scents: anise, apple, hibiscus, lavender, lemon, sweet orange, and vanilla.
- Textures for tactile engagement. Included were squares of a plastic doormat, smooth foam, a rubber sink mat, aluminum foil, felt, fine sandpaper, and sponges.
- Objects for motor engagement. The kit had a small piggy bank with plastic coins, miniature plastic fruits, colored beads, and more than 20 small toys of varying dimensions.
- Music for auditory engagement. A CD player with the CD Classical Music for People Who Hate Classical Music, Vol. 1 was part of the kit.
- Miscellaneous other supplies like bowls, pictures of well-known paintings, and a container of Play-Doh.
Parents supplied some additional objects for the sensorimotor exercises like a wooden plank, scented bath soap, ice, pillows, and other common items.
The children participating in the sensorimotor enrichment therapy did parent-guided sensorimotor exercises throughout the day.
- Children received exposure to four different fragrances each day. Their parents placed a drop of an essential oil on a cotton ball in glass vial. Children sniffed the scent for one minute while rubbing their backs with a closed hand.
- At night, parents again exposed their children to a fragrance. Parents placed a scented cotton ball in their child’s pillowcase before bedtime.
- Each day, the children listened to the classical music CD. This was paired with tactile stimulation by using headphones. Some children refused to use headphones and listened to the music on speakers instead.
- Parents received instructions for 34 sensorimotor exercises. The parents were to engage children in four to seven of the exercises each day, completing a different set of exercises every two weeks. The exercises, which were “somewhat arbitrary combinations of sensory stimuli,” according to Woo and Leon, took 15 to 30 minutes to complete each day. The exercises included tasks like placing hands or feet in water of various temperatures or picking out colored beads from a plate of ice cubes.
The children who participated in the sensorimotor enrichment had better scores at the end of the study than the children who received standard care. Children from both groups had roughly equal scores at the outset of the study.
By the end of the study, the sensorimotor enrichment group had higher scores on the Leiter-R test. Of the sensorimotor enrichment group, 42% demonstrated clinically significant improvements in autism severity, as measured by the CARS, compared to only seven percent of the standard care group. In 11 of 15 items assessed by the CARS, including emotional responses and body and object use, there was greater improvement in the sensorimotor enrichment group than in the standard care group.
Parent reports suggest that sensorimotor enrichment therapy is more effective than standard care. Sixty-nine percent of parents of children in the sensorimotor enrichment group reported improvements, but only 31% of parents of children in the standard care group reported the same.
There were no differences on the Expressive One-Word Picture Vocabulary Test at the end of the study. This indicates that sensorimotor enrichment therapy does not improve communication skills.
The most exciting aspect of this study is that sensorimotor enrichment therapy is relatively simple to use. It is equally or more effective than established therapy methods like applied behavior analysis and the Denver Model. Alternative models require 20 or more hours per week of therapy, but sensorimotor enrichment takes only five to nine hours per week. Sensorimotor enrichment therapy is something that parents can use as an in-home intervention for children struggling to cope with sensory stimuli and to help children develop motor skills.
Certified Autism Specialists are in the perfect position to deploy therapies like this in their practice. Because sensorimotor enrichment uses household objects, Certified Autism Specialists can use elements of sensorimotor enrichment during sessions with patients or set up a schedule for in-home enrichment therapy with patients and their guardians.
By keeping up with news and research in autism, clinicians, teachers, and parents can better support people with autism. The International Board of Credentialing and Continuing Education Standards is here to help you stay on top of important developments in autism research.
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Centers for Disease Control and Prevention (March 24, 2014). Diagnostic criteria for 299.00 autism spectrum disorder. Retrieved from http://www.cdc.gov/ncbddd/autism/hcp-dsm.html.
Woo, C. C., & Leon, M. (2013). Environmental enrichment as an effective treatment for autism: A randomized controlled trial. Behavioral Neuroscience, 127(4), 487-497.