Evaluation of the Effects of Lag Schedules on Response Variability with Multimodal Communication

The American Speech-Language-Hearing Association (n.d.) suggests that acquisition and use of augmentative and alternative communication (AAC) is dynamic and that learning multiple modalities may be beneficial particularly for those individuals with severe disabilities. Evaluation of response variability after training multiple modalities has yet to be explored. One advantage of learning multiple modalities manifests when an individual encounters communication breakdowns. Researchers replicated the procedures of Adami et al. (Behav Anal Pract 10:209-213, 2017) using a B-A-B-A design to determine the impact of lag schedules of reinforcement on response variability and persistence after participants learned two modalities simultaneously. Results demonstrated all three participants interchanged modalities and responding persisted when faced with a challenge to treatment in the form of a lag schedule. The Lag 1 schedule yielded higher variation of responding in comparison to the Lag 0 conditions. The current study extends response variability literature and preliminarily suggests that adding contrived communication breakdowns into AAC training may strengthen an individual’s multimodal communication repertoire.