MULTIPLE TREATMENT INTERFERENCE IN THE ALTERNATING TREATMENTS DESIGN AS A FUNCTION OF THE INTERCOMPONENT INTERVAL LENGTH

In experimental designs requiring the administration of more than one treatment to the same subject(s), the effect of one treatment may be influenced by the effect of another treatment (Campbell & Stanley, 1963), a phenomenon known as multiple treatment interference. We conducted two studies in which multiple treatment interference in an alternating treatments design was shown to be a function of the length of the intercomponent interval (ICI) separating treatment conditions. In the first study, we evaluated the effects of four different treatments on the mouthing of a severely retarded boy. Under a 1-min ICI no consistent differential responding to treatment was obtained. Differential responding emerged when the ICI was increased from 1 min to 120 min, thus suggesting multiple treatment interference in the lack of differential responding under a 1-min changeover interval. Functional control of the nondifferential and differential responding as a function of the ICI length was replicated in a reversal phase. In the second study, we compared two treatment procedures for the disruptive noncompliant behavior of a moderately retarded boy. Multiple treatment interference (i.e., the lack of differential responding) occurred with the 1-min intercomponent interval. An increase to a 120-min ICI again resulted in differential responding. A replication of multiple treatment interference by a reversal to a short interval phase was not achieved in the second subject. Results of this study support much of the basic literature on discrimination and multiple treatment interference. Major findings of this study are twofold: Multiple treatment interference can depend on the length of the changeover interval between treatments and multiple treatment interference can take the form of a lack of differential responding to various treatments. Implications for future research are discussed.     

AN EVALUATION OF GENTLE TEACHING AND VISUAL SCREENING IN THE REDUCTION OF STEREOTYPY

Gentle teaching and visual screening techniques have been used to control severe behavior problems in persons with mental retardation. An alternating treatments design was used to compare gentle teaching, visual screening, and a task-training condition in the reduction of the high-level stereotypy of 3 persons with mental retardation. Following a baseline phase, a task-training condition using standard behavioral techniques was implemented to establish the effects of training the subjects on the tasks. Results showed a modest decrease in stereotypy. This phase was followed by an alternating treatments phase in which visual screening, gentle teaching, and baseline conditions were compared. Both procedures were superior to the control condition in reducing stereotypic behavior, with visual screening being more effective than gentle teaching. When compared with data from the prior phase, gentle teaching was found to be more effective than task training for 2 subjects but less effective for the 3rd, whose stereotypy increased during gentle teaching. Two succeeding phases in which visual screening was implemented across two and then all three daily conditions reduced stereotypy further to near-zero levels. An additional phase with 1 subject demonstrated that the treatment effects of visual screening were easily replicated across therapists. Mixed and idiosyncratic changes in collateral behaviors occurred. For example, “bonding,” the goal of gentle teaching, occurred at the same low levels under both treatments, contrary to the predictions of gentle teaching's proponents. The results indicate that gentle teaching may not be the universal treatment of choice for stereotypy its proponents suggest, and that it requires further empirical evaluation.     

THE EFFECTS OF SINGLE INSTANCE,MULTIPLE INSTANCE,AND GENERAL CASE TRAINING ON GENERALIZED VENDING MACHINE USE BY MODERATELY AND SEVERELY HANDICAPPED STUDENTS

This report provides an experimental analysis of generalized vending machine use by six moderately or severely retarded high school students. Dependent variables were training trials to criterion and performance on 10 nontrained “generalization” vending machines. A multiple-baseline design across subjects was used to compare three strategies for teaching generalized vending machine use. Training occurred with (a) a single vending machine, (b) three similar machines, or (c) three machines that sampled the range of stimulus and response variation in a defined class of vending machines. Results indicated that the third approach was the most effective method of obtaining generalized responding. Methodological implications for the experimental analysis of generalization and programmatic implications for teaching generalized behaviors are discussed.     

SPIRIT, METHOD, AND CONTENT IN SCIENCE AND RELIGION: THE THEOLOGICAL PERSPECTIVE OF A GENETICIST

Abstract. There are three ways in which bridges may be built between science and theology: spirituality, methodology, and content. Spirituality is the power which drives each to address reality and the expectations with which each approaches the pursuit of truth. The methodology of science is summarized in terms of three activities: taxonomy; the hypothetico-deductive cycle; derivative technology. The content of science, especially with respect to the phenomena of givenness, connectedness and openness in the life sciences, is correlated with theological constructs. Attention is drawn to the role of the double helix in biology and a possible parallel is proposed to the function of the icon in religion and theology.     

IMPROVING SOCIAL INTERACTION IN A CHRONIC PSYCHOTIC USING DISCRIMINATED AVOIDANCE (“NAGGING”): EXPERIMENTAL ANALYSIS AND GENERALIZATION

Three social-interaction behaviors of a withdrawn, chronic schizophrenic were increased using a discriminated avoidance (“nagging”) procedure. The three behaviors were: (a) voice volume loud enough so that two-thirds of his speech was intelligible at a distance of 3 m; (b) duration of speech of at least 15 sec; (c) placement of hands and elbows on the armrests of the chair in which he was sitting. “Nagging” consisted of verbal prompts to improve performance when the behaviors did not meet their criteria. A combined withdrawal and multiple-baseline design was used to evaluate the effectiveness of the procedure, and the contingency was sequentially applied to each of the three behaviors in each of four different interactions to determine the degree of stimulus and response generalization. Results indicated that the contingency was the effective element in increasing the patient's appropriate performance, and that there was a high degree of stimulus generalization and a moderate degree of response generalization. After the patient's discharge from the hospital, the durability of improvement across time and setting was determined in followup sessions conducted at a day treatment center and at a residential care home. Volume and duration generalized well to the new settings, while arm placement extinguished immediately.     

PARENT EDUCATION PROJECT III: INCREASING AFFECTION AND RESPONSIVITY IN DEVELOPMENTALLY HANDICAPPED MOTHERS: COMPONENT ANALYSIS,GENERALIZATION, AND EFFECTS ON CHILD LANGUAGE

We evaluated the effects of a parent training program consisting of verbal instruction, modeling, and feedback on the affection and responsivity of 3 developmentally handicapped mothers towards their children. The results indicated the following: First, the training package increased maternal physical affection, praise, and imitation of child vocalizations. These parenting skills increased to levels found in comparison groups of nonhandicapped mothers. Second, the training package was more effective than verbal instruction alone, the latter being the predominant method presently used by social service workers. Third, most maternal gains were maintained over a 3- to 18-month follow-up period, although one mother required a reinforced maintenance procedure. Fourth, instructing mothers to generalize served to increase the generalization of newly acquired skills from play times (the training context) to child-care tasks (e.g., diapering, feeding). Fifth, teaching the parents to imitate child vocalizations was related to gains in both the frequency and quality of verbal behavior of the two language delayed children as measured by standardized developmental tests and in vivo comparisons with age-matched children (who had nonhandicapped parents). These results show that behavioral instruction can improve important child-rearing skills of developmentally handicapped mothers, with corresponding benefits to their children.     

IMPULSIVITY IN STUDENTS WITH SERIOUS EMOTIONAL DISTURBANCE: THE INTERACTIVE EFFECTS OF REINFORCER RATE,DELAY, AND QUALITY

We conducted two studies extending basic matching research on self-control and impulsivity to the investigation of choices of students diagnosed as seriously emotionally disturbed. In Study 1 we examined the interaction between unequal rates of reinforcement and equal versus unequal delays to reinforcer access on performance of concurrently available sets of math problems. The results of a reversal design showed that when delays to reinforcer access were the same for both response alternatives, the time allocated to each was approximately proportional to obtained reinforcement. When the delays to reinforcer access differed between the response alternatives, there was a bias toward the response alternative and schedule with the lower delays, suggesting impulsivity (i.e., immediate reinforcer access overrode the effects of rate of reinforcement). In Study 2 we examined the interactive effects of reinforcer rate, quality, and delay. Conditions involving delayed access to the high-quality reinforcers on the rich schedule (with immediate access to low-quality reinforcers earned on the lean schedule) were alternated with immediate access to low-quality reinforcers on the rich schedule (with delayed access to high-quality reinforcers on the lean schedule) using a reversal design. With 1 student, reinforcer quality overrode the effects of both reinforcer rate and delay to reinforcer access. The other student tended to respond exclusively to the alternative associated with immediate access to reinforcers. The studies demonstrate a methodology based on matching theory for determining influential dimensions of reinforcers governing individuals' choices.