Maintenance and generalization of skills acquired through picture exchange communication system (PECS) training: a long-term follow-up.

To conduct a follow-up assessment of the maintenance of communication skills of a 7-year-old child with autism spectrum disorder, 3 years 7 months post PECS training; and investigate the effects of environmental adaptations on the child's PECS and vocal communications. An alternating-treatments design enabled comparison of the effects of two treatment conditions (an environmental adaptation to increase need and opportunities for communication, versus a continuation of baseline procedures) on the child's PECS and vocal communications in the child's home. Baseline data demonstrated decreased levels of PECS and vocal communication at follow-up, compared to post PECS training 3 years 7 months prior. The environmental adaptation had no observable effect on the participant's use of PECS, but vocal manding increased in this condition. These results suggest ongoing need for motivating environments with ample opportunities to practice post PECS training. Implications and directions for future research are discussed.