The Inadvertent Effects of PECS on Vocal Responding of Children with Autism Spectrum Disorder

Objectives The Picture Exchange Communication System (PECS) is a widely used alternative and augmentative communication (AAC) system for children with autism spectrum disorder (ASD) who have limited or no vocal abilities. Vocalizations may emerge with the use of PECS particularly during the training phases. One question that often arises is what effect continued use of PECS has on vocal behavior. The current study evaluated the effects of PECS on vocal responding for participants who had been using PECS for at least 1 year. Methods Four children with ASD participated in this study. Each had functional vocal communication skills but used PECS as their primary mode of communication. One of the participants also used sign language. The effects of PECS on vocal responding were evaluated in two studies using a reversal design. Results The use of PECS inhibited vocal responding if both modes of communication were on the same schedule of reinforcement. When PECS was placed on extinction (study 1) or removed (study 2), vocal responding increased across subjects. Conclusions If vocal responding and PECS remain on the same schedule of reinforcement, vocal responses may be suppressed and, consequently, improvements in functional vocal communication may not be seen. Additional studies are needed to replicate the current findings as well as to determine if PECS should be faded if functional vocal communication is established.