REINFORCEMENT DELAY FADING DURING DIFFERENTIAL REINFORCEMENT OF COMMUNICATION: THE EFFECTS OF SIGNALS ON RESPONSE MAINTENANCE MICHAEL E. KELLEY 1 ,DOROTHEA C. LERMAN 2 ,WAYNE W. FISHER 1 ,HENRY S. ROANE 3 , AND AMANDA N. ZANGRILLO 4 1 MUNROE-MEYER INSTITUTE AND UNIVERSITY OF NEBRASKA MEDICAL CENTER 2 UNIVERSITY OF HOUSTON CLEARLAKE 3 SUNY UPSTATE MEDICAL UNIVERSITY 4 THE UNIVERSITY OF SOUTHERN MAINE Signals during delays to reinforcement may lessen reductions in responding that typically occur when there is a delay between a response and its reinforcer. Sparse applied research has been devoted to understanding the conditions under which responding may be maintained when delays to reinforcement are introduced. We evaluated the extent to which providing signals during delay fading affected responding in the context of differential reinforcement of communication responses. Three individuals were exposed to gradually increasing signaled and unsignaled reinforcement delays in multiple-schedule and/or withdrawal designs. Results for 2 of 3 participants suggested that (a) the presence of signals facilitated response maintenance under delayed reinforcement and (b) coordinated basic and applied research may advance both conceptual understanding and clinical outcomes of delayed reinforcement. Key words: translational research, delay fading, delayed reinforcement, functional communication training, communication, signaled delays, stimulus control _______________________________________________________________________________ Delayed reinforcement is an area of re- search that has drawn considerable attention from both basic and applied researchers. Azzi, Fix, Keller, and Rocha e Silva (1964) conduct- ed a preliminary study on the effects of exteroceptive stimuli on responding during delays to reinforcement. Responding was more regular and occurred at higher rates during conditions in which a change in the lighting in the operant chamber was correlated with the delay interval. This effect has been replicated across several studies, despite significant pro- cedural variation (e.g., Lattal, 1984; Richards, 1981). For example, Lattal showed that, in general, signaled delays maintained response rates close to baseline levels, and that un- signaled delays produced large decrements in responding compared to an immediate-rein- forcement baseline. In a follow-up experi- ment, Lattal also showed an important relation between the percentage of delay intervals that were signaled and response maintenance. Response rates were positively correlated with the percentage of delay intervals that included a signal. Schaal and Branch (1988) compared re- sponse rates under conditions of unsignaled, briefly signaled, and completely signaled de- lays to reinforcement. A 1-s reinforcement delay decreased responding relative to a variable-interval (VI) 60-s schedule with imme- diate reinforcement. Response rates returned to immediate-reinforcement levels when a signal (i.e., a change in the color of the key light) was introduced during the first 0.5 s of the delay. Response rates comparable with immediate reinforcement were maintained with this brief signal at 1-s, 3-s, and 9-s delays, but not at 27-s delays. Results of a subsequent experiment showed that a signal lasting the entire delay was necessary to maintain re- sponding under the 27-s delay condition. Schaal and Branch suggested that signals may function as conditioned reinforcers, and thus, help to ‘‘bridge the gap’’ between the occur- rence of the response and reinforcer delivery. Although basic research on the efficacy of providing signals suggests a rather robust effect for response maintenance during rein- This research was supported in part by a grant from the Louisiana State Board of Regents and Grant No. 5 R01 HD37837-03 from the Department of Health and Human Services, the National Institute of Child Health and Human Development. This research was conducted in partial fulfillment for the doctoral degree from Louisiana State University for the first author. Correspondence concerning this article should be sent to Michael E. Kelley, Munroe-Meyer Institute, UNMC, 985450 Nebraska Medical Center, Omaha, NE 68198-5450 (e-mail: michael.kelley@unmc.edu). doi: 10.1901/jeab.2011.96-107 JOURNAL OF THE EXPERIMENTAL ANALYSIS OF BEHAVIOR 2011, 96, 107–122 NUMBER 1( JULY) 107