Evaluation of child variables related to outcomes of the Picture Exchange Communication System in children with autism spectrum disorders

Autism spectrum disorders (ASD) refer to a cluster of pervasive developmental disorders, including classic autism, characterized by varying impairment in communication, social interaction, and restricted and repetitive behaviour. One-third to one-half of children with autism lack functional speech. As a result, the majority of interventions focus on the development of communication skills. A frequently used augmentative and alternative communication system is the Picture Exchange Communication System (PECS; Bondy & Frost, 2002). Children learn to exchange a picture for a desired item and, subsequently, to construct picture sentences, respond to questions, and make comments on the world around them. Accumulating research suggests the effectiveness of PECS with this population, although little is known about the child and treatment factors that are related to variability in communication outcomes. Within the following three studies, PECS outcomes are explored in relation to child variables using a pre- post-treatment design. Specific outcomes examined include the phase of PECS mastered, generalization of PECS skills, and speech production post-treatment. In Study 1, the PECS teaching protocol and empirical literature is reviewed. In Study 2, PECS outcomes are explored in relation to children's chronological age, developmental level, severity of symptoms of ASD, and associative learning with pictures. Finally, in Study 3, PECS outcomes are examined in relation to higher level cognitive skills such as a symbolic understanding of pictures. The developmental sequence of associative learning and symbolic ability with pictures and their relative contribution to PECS outcomes is explored.