Stimulus characteristics within directives: effects on accuracy of task completion.

Three experiments were conducted in an outpatient setting with young children who had been referred for treatment of noncompliant behavior and who had coexisting receptive language or receptive vocabulary difficulties. Experiment 1 studied differential responding of the participants to a brief hierarchical directive analysis (least-to-most complex stimulus prompts) to identify directives that functioned as discriminative stimuli for accurate responding. Experiment 1 identified distinct patterns of accurate responding relative to manipulation of directive stimulus characteristics. Experiment 2 demonstrated that directives identified as effective or ineffective in obtaining stimulus control of accurate responding during Experiment 1 continued to control accurate responding across play activities and academic tasks. Experiment 3 probed effects of the interaction between the type of directive (effective vs. ineffective) and the reinforcement contingency (differential reinforcement for attempts vs. differential reinforcement for accurate responses) on accurate task completion and disruptive behavior. Results suggested that behavioral escalation from inaccurate responding to disruptive behavior occurred only when ineffective directives were combined with differential reinforcement for accurate task completion. The overall results are discussed in terms of developing a methodology for identifying stimulus characteristics of directives that affect accurate responding.

Functional analysis and treatment of breath holding maintained by nonsocial reinforcement.

A functional analysis showed that breath holding exhibited by a 16-year-old boy with mental retardation occurred independent of social consequences. Assessment results of the existing treatment procedure-a verbal reprimand-were used to design a treatment package that reduced the behavior to low levels across 7 months.

Assessment of a response bias for aggression over functionally equivalent appropriate behavior.

We evaluated the effects of a dense (fixed-ratio 1) schedule of reinforcement for an 11-year-old boy's mands for toys while aggression produced the same toys on various schedules chosen on the basis of a progressive-ratio probe. Based on the probe session data, we accurately predicted that aggression would be more probable than mands when the schedules were equal or slightly discrepant, but that mands would be more probable when the schedule discrepancy was large.

A brief method for conducting a negative-reinforcement assessment.

A brief negative-reinforcement assessment was conducted with developmentally disabled children with severe destructive behavior. Five children were trained to engage in a simple escape response (e.g., a hand clap). Then each child was presented with a variety of stimuli or tasks that ranged on a scale from preferred to nonpreferred, based on parent ranking. The participant received a brief break from the stimuli or task, contingent on each escape response. For one child, an avoidance contingency was also implemented in which he could engage in the response to avoid the presentation of stimuli. Results showed that for each child, several stimuli were identified that may serve as effective negative reinforcers. Results also indicated that the procedure did not elicit any negative side effects for four children and low rates of destructive behavior for the fifth child. For one child, the results of the negative-reinforcement assessment were used to develop an effective treatment for destructive behavior. Additional applications of the reinforcement assessment to treatment interventions is discussed, as well as limitations to the procedure.

On the relative reinforcing effects of choice and differential consequences.

Research on the reinforcing effects of providing choice-making opportunities to individuals with developmental disabilities (i.e., allowing them to choose reinforcers or tasks) has produced inconsistent results, perhaps because the mechanisms underlying such effects remain unclear. Choice may produce a reinforcement effect because it is correlated with differential consequences (i.e., choice may increase one's access to higher preference stimuli), or it may have reinforcement value independent of (or in addition to) the chosen stimulus. In Experiment 1, we used a concurrent-operants arrangement to assess preference for a choice condition (in which participants selected one of two available reinforcers) relative to a no-choice condition (in which the therapist selected the same reinforcers on a yoked schedule). All 3 participants preferred the choice option. In Experiment 2, we altered the schedules so that the participant selected one of two lower preference reinforcers in the choice condition, whereas the therapist selected a higher preference stimulus for the participant either half or all of the time in the no-choice condition. Participants typically allowed the therapist to select reinforcers for them (i.e., they allocated responding to the no-choice condition) when it resulted in greater access to higher preference stimuli.

Effects of reinforcement choice on task responding in individuals with developmental disabilities.

The effects of reinforcement choice on task performance were examined with 6 individuals who had been diagnosed with severe to profound mental retardation. Five highly preferred items were identified for each participant via stimulus preference assessments. Participants then were exposed to choice and no-choice conditions that were alternated within reversal and multielement designs. During choice sessions, participants were permitted to select between two preferred stimuli contingent on responding. During no-choice sessions, the therapist delivered a single item contingent on responding. Preference for the stimuli was held constant across conditions by yoking the items delivered during no-choice sessions to those selected during the immediately preceding choice sessions. All participants exhibited similar rates of responding across choice and no-choice conditions. These findings indicate that for individuals with severe disabilities, access to choice may not improve task performance when highly preferred items are already incorporated into instructional programs.