Replication and Extension of the Effects of Lag Schedules on Mand Variability and Challenging Behavior During Functional Communication Training

More is known about how to reduce challenging behavior with functional communication training (FCT) than how to mitigate its resurgence during or following a course of treatment. Research suggests reinforcing mand variability during FCT may mitigate the resurgence of challenging behavior, but validated procedures for reinforcing mand variability are limited and poorly understood. Lag schedules can reinforce variability in verbal behavior such as manding in individuals with autism, but studies have been largely limited to nonvocal mand modalities. Therefore, in the current study, we further evaluated the effects of FCT with lag schedules on vocal mand variability and challenging behavior in children with autism. The results suggest lag schedules alone or in combination with response prompt-fading strategies during FCT can increase mand variability and expand mand response classes but may fail to produce clinically significant reductions in challenging behavior.

Lag Schedules and Functional Communication Training: Persistence of Mands and Relapse of Problem Behavior

We evaluated the effects of lag schedules of reinforcement and functional communication training (FCT) on mand variability and problem behavior in two children with autism spectrum disorder. Specifically, we implemented FCT with increasing lag schedules and compared its effects on problem behavior with baseline conditions. The results showed that both participants exhibited low rates of problem behavior during treatment relative to baseline during and following schedule thinning (up to a Lag 5 schedule arrangement). Variable and total mands remained high during schedule thinning. With one participant, variable manding persisted when the value of the lag schedule was reduced to zero. The current results are discussed in terms of implications for training multiple mand topographies during FCT for the potential prevention and/or mitigation of clinical relapse during challenges to treatment.

Translational evaluation of a lag schedule and variability in food consumed by a boy with autism and food selectivity

PURPOSE

To evaluate the effects of a lag schedule of positive reinforcement on variability in food consumed by a boy with autism and food selectivity.

METHODS

Using single-subject experimental design methodology, an ABAB design was employed. During lag 0 (condition A), high-preferred toys were delivered contingent on consumption of any food. During lag 1 (condition B), high-preferred toys were delivered contingent on consumption of different foods within session.

RESULTS

Higher levels of variability in within-session consumption were observed during lag 1 conditions.

CONCLUSIONS

The lag 1 schedule of reinforcement increased variability in food consumed. This finding adds to the literature by demonstrating a novel experimental arrangement that may be used in applied studies to evaluate the clinical utility of differentially reinforcing variability in the treatment of food selectivity associated with autism.

An analysis of procedures that affect response variability

Response variability is sensitive to antecedent and consequent manipulations. Researchers have investigated inducement, direct production through reinforcement, and stimulus control of response variability. Recently, researchers have shown that lag reinforcement schedules reliably increase variability but may also produce higher-order stereotypy. There has been limited investigation of appropriate variability levels and alternation between repetition and variation. In a three-part study, we evaluated levels of variability across a group of children, the effects of various procedures on producing response variability and novelty, and the use of schedule-correlated stimuli for producing rapid alternation between repetition and variation. In Study 1, there was a nearly bimodal distribution of children emitting either low or high variability. In Study 2, for most children, fixed lag 4 and variable lag 4 schedules produced the highest levels of variability and novelty. In Study 3, responding was brought under control of schedule-correlated stimuli, allowing for rapid alternation between repetition and variation.

Using a lag reinforcement schedule to increase phonemic variability in children with autism spectrum disorders

Shaping functional vocal language is difficult when an individual has not yet acquired an echoic repertoire and does not emit sufficient phonemes (i.e., speech sounds) for shaping. Few studies have evaluated interventions to increase the frequency and breadth of phonemes. The current study extended Esch, Esch, and Love (2009) by evaluating the effects of a Lag 1 reinforcement schedule on vocal variability and limiting the definition of variability to responses that incorporated a novel phoneme. For 2 of the 3 participants, the cumulative number of novel phonemes, the percentage of trials with variability, and the number of different phonemes emitted per session increased during the Lag 1 intervention phase.

Use of a lag differential reinforcement contingency to increase varied selections of classroom activities

The present study evaluated the effects of a lag differential reinforcement contingency on 2 students' activity selections using reversal designs. Results showed that the lag contingency was responsible for promoting increased novel selections, engagement in diverse activities, and greater progress with respect to programmed academic activities.