Concomitants of success in acquiring an augmentative communication system: changes in attention, communication, and sociability.

Evidence was presented that successful participation in augmentative communication intervention can foster developmental changes that extend beyond the targeted effect. Ten persons with severe mental retardation were assigned in matched pairs to a lexigram condition (graphic symbols) or a control condition (social stimulation). A coding system, developed to assess pre- versus postintervention performance in four domains, was applied to videotapes of each subject in dyadic interaction. The 3 subjects who successfully acquired lexigrams exhibited changes in attention, intentional communication, and sociability; the other subjects improved only in sociability. Supporting results were obtained using an abbreviated coding system. Application of the coding systems to additional subject populations and interventions would clarify how broadly the results generalize.