Doctor of Philosophy (PhD)



Document Type



Functional communication training (FCT) is a commonly used intervention for severe behavior disorders (e.g., Carr & Durand, 1985; Wacker et al., 1990). This treatment is designed to provide individuals with developmental disabilities with a repertoire of responses to attain reinforcement. However, caregivers may be unable or unwilling to provide immediate reinforcement when the treatment is implemented in the natural environment. Recent applied research on responding during delayed reinforcement suggests that responding may not persist when delays exceed 30 s (e.g., Fisher, Thompson, Hagopian, Bowman, & Krug, 2000; Hanley, Iwata, & Thompson, 2001). In contrast, results of basic research suggest that providing signals during delays may attenuate decrements in responding. The purpose of the current study was to evaluate the extent to which signals may influence responding when the delays to reinforcement are gradually increased over time. In Experiment 1, two individuals were exposed to gradually increasing delays in the context of a multielement design. The presence of a signal did not produce higher response rates or greater response persistence than when a signal was not present. For a third participant, baseline response patterns suggested interaction effects would have influenced her behavior if she had been exposed to the comparison. In Experiment 2, all participants were exposed to signaled and unsignaled delay fading in the context of a reversal design. Results for 2 of 3 participants showed that responding persisted at lengthier reinforcement delay values when signals were used. These results suggested that, for 2 participants, (a) interaction effects influenced responding in Experiment 1, and that (b) the presence of signals facilitated response maintenance during delayed reinforcement.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Dorothea C. Lerman

Included in

Psychology Commons