This post originally appeared in the January 2009 print version of Motivations.
In the last issue, I described our family’s experience selecting an augmentative and alternative communication (AAC) device for our daughter with autism. I left off with the question ‘where is the research that supports the assumption that assistive technology can help teach kids with autism?’ There is a developing body of research in this area. Fortunately, two useful reviews of this research have been published in journals of the American Speech-Language-Hearing Association (ASHA). ASHA is the professional association of speech-language pathologists – most likely your child’s speech therapist is a member.
The first review, by Millar at al in 2006 (1), looked at the impact of AAC on the speech of individuals with various developmental disabilities. The researchers assessed the effects of implementing AAC devices on speech across 23 studies with a total of 67 participants. 31% participants had autism, the remainder other developmental disabilities (mental retardation, Klinefelter’s, cerebral palsy).
The first question on the minds of the researchers mirrored the one most on the minds of parents – will using AAC decrease the likelihood that my child will ever speak? Results show it is unlikely – 82% of the participants increased their speech, 11% were unchanged, and only 7% had speech decreases. This result allows for significant variations in how well the studies were controlled. When the review drills down to the 6 most carefully designed studies, which represent the best evidence, none of the 17 participants in the 6 studies showed a decrease in speech. 94% of these participants showed an increase instead.
Particularly heartening is the fact that not all of these participants were young children. Many parents fear that after some threshold age speech is beyond hope. The researchers note the studies “suggest that speech gains may still be realized by individuals with developmental disabilities well past the critical early childhood years.”
Based on all the evidence they reviewed, the authors conclude “clinicians and parents should not hesitate to introduce AAC interventions to individuals…whose speech is inadequate to meet their communication needs.” As an autism parent, I wondered ‘Do these results hold if you limit the studies to just the participants with autism?’ Last year, Schlosser and Wendt issued another research review (2) targeted to autism populations. They looked at 9 single-subject design studies (27 participants) and 2 group studies (98 participants). Using larger studies and more rigorous criteria, these researchers had the same finding: “There is currently no evidence that AAC intervention hinders speech production in children with autism or PDD-NOS.” While the speech gains they found in the studies are variable and usually small, the authors emphasized these gains are in addition to the direct communication benefits of the AAC use itself – “gains in speech production ought to be viewed as a bonus of AAC interventions rather than as an expectation.”
The studies included in both reviews implemented AAC along with a wide variety of teaching approaches. Is there evidence specific to using AAC in the context of applied behavior analysis (ABA)? There are some encouraging results, but we need more. In 1998, Schepis et al (3) implemented voice output devices in a natural environment teaching setting similar to those used in verbal behavior or pivotal response training ABA programs. Observing 4 students in two classroom routines (snack and play), again there was no evidence of speech loss. Instead, all students increased their language use in all forms – voice output, gestures, nonword sounds and speech. Most encouraging, the students increased their spontaneous language: “each child used the [voice output device] consistently without a specific verbal prompt to communicate, and used it relatively frequently without any preceding verbal behavior from a staff person.” The AAC use by the children even improved the behavior of the teachers, with staff interaction with students increasing significantly in response to spontaneous AAC use.
Another ABA-based study published this winter (4) cautions against the idea that synthesized speech from AAC devices may be more effective with children with autism due to its consistency. The researchers found students still respond better to spoken language models, but they conclude the results “should not be used as evidence against the potential effectiveness of speech-generating devices to facilitate language acquisition in children with autism.”
Hopefully, additional studies in the years ahead will detail how to best integrate AAC devices into ABA programs and identify the children who respond best. Meanwhile, parents and teachers can feel comfortable that the existing literature supports efforts to use these devices with children who have not yet developed speech or sign language skills.
1 Millar, Diane C., Janice C. Light and Ralf W. Schlosser. (2006) The Impact of Augmentative and Alternative Communication Intervention on the Speech Production of Individuals with Developmental Disabilities: A Research Review. Journal of Speech, Language and Hearing Research, 49, 248-264.
2 Schlosser, Ralf W. and Oliver Wendt. (2008) Effects of Augmentative and Alternative Communication Intervention on Speech Production in Children with Autism: A Systematic Review. American Journal of Speech-Language Pathology, 17, 212-230.
3 Schepis, Maureen M., Dennis H. Reid, Michael M. Behrmann and Kelly Sutton. (1998) Increasing Communication Interactions of Young Children with Autism Using a Voice Output Communication Aid and Naturalistic Teaching. Journal of Applied Behavior Analysis, 31, 561-578.
4 Ferris, Kelly J. and Michael A. Fabrizio. (2008) Comparison of Error Correction Procedures Involving a Speech-Generating Device to Teach a Child with Autism New Tacts. Journal of Speech-Language Pathology and Applied Behavior Analysis, 3.3, 47 – 59.
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