EFFECTS OF A VARIABLE-RATIO REINFORCEMENT SCHEDULE WITH CHANGING CRITERIA ON EXERCISE IN OBESE AND NONOBESE BOYS

The effects of a variable-ratio schedule of reinforcement on pedaling a stationary exercise bicycle were examined. Three obese and three nonobese 11-year-old boys were individually tested five times weekly for approximately 12 weeks. A changing-criterion design was used in which each successive criterion was increased over mean performance rate in the previous phase by approximately 15%. The contingencies of the successive criteria resulted in systematic increases in rate of exercise for all children. Final variable-ratio rates were higher than those under fixed ratios found in previous research, with rates for 2 of the 3 obese boys approximating those of the nonobese.     

THE USE OF BEHAVIORAL ASSESSMENT TO PRESCRIBE AND EVALUATE TREATMENTS FOR SEVERELY HANDICAPPED CHILDREN

Behavioral assessment procedures were used to prescribe and evaluate treatments of maladaptive behavior for 2 children with severe multiple handicaps. In Experiment 1, the results of an assessment of reinforcer preference were used in conjunction with a functional analysis of the conditions maintaining self-injurious behavior to prescribe a treatment for a child with severe disabilities. The treatment procedure involved the use of a pressure-sensitive microswitch to activate reinforcing stimuli during two solitary conditions, during which self-injurious behavior had occurred at high rates. The results were evaluated with a multiple baseline across settings design and indicated that self-injury decreased with concomitant increases in microswitch activation. Results were maintained at 6 weeks, 8 weeks, and 6 months. In Experiment 2, the results of behavioral assessments of reinforcer preference and self-injurious behavior were combined to develop a treatment for a second severely handicapped child, who exhibited high rates of self-injury in demand situations. This treatment was evaluated with a multiple baseline across tasks design and resulted in the elimination of self-injury for up to 15 months.     

PARENTAL INFLUENCES ON CHILDREN'S EATING BEHAVIOR AND RELATIVE WEIGHT

We investigated the relationship between selected parent behaviors, child mealtime behavior, and infant relative weight. Subjects were 7 male and 7 female children varying in age from 12 to 30 months (mean = 23.9 months). Each subject and parents were observed during the dinnertime meal on two occasions using the BATMAN (Bob and Tom's Method of Assessing Nutrition). The children spent 58% of the mealtime eating. They spent very little time making active decisions about what and how much they ate (food requests = 2% of the time; food refusals = 1% of the time). We found significant correlations between child relative weight and (a) parental prompts to eat (r = .81, p < .001), (b) parental food offers (r = .51, p < .05), and (c) parental encouragement to eat (r = .82, p < .001). Thus, the present study suggests a relationship between certain parental variables and the relative weight of their children.     

EMERGENCE OF REINFORCER PREFERENCE AS A FUNCTION OF SCHEDULE REQUIREMENTS AND STIMULUS SIMILARITY

Tustin (1994) recently observed that an individual's preference for one of two concurrently available reinforcers under low schedule requirements (concurrent fixed-ratio [FR] 1) switched to the other reinforcer when the schedule requirements were high (concurrent FR 10). We extended this line of research by examining preference for similar and dissimilar reinforcers (i.e., those affecting the same sensory modality and those affecting different sensory modalities). Two individuals with developmental disabilities were exposed to an arrangement in which pressing two different panels produced two different reinforcers according to progressively increasing, concurrent-ratio schedules. When two dissimilar stimuli were concurrently available (food and a leisure item), no clear preference for one item over the other was observed, regardless of the FR schedules in effect (FR 1, 2, 5, 10, and 20). By contrast, when two similar stimuli were concurrently available (two food items), a clear preference for one item emerged as the schedule requirements were increased from FR 1 to FR 5 or FR 10. These results are discussed in terms of implications for conducting preference assessments and for selecting reinforcers to be used under training conditions in which response requirements are relatively high or effortful.     

THE COSTS OF EATING: A BEHAVIORAL ECONOMIC ANALYSIS OF FOOD REFUSAL

Behavioral economic concepts were applied to the analysis and treatment of pediatric feeding disorders in a clinical setting. In Experiment 1, children who chronically refused food were presented with varying amounts of food on a spoon (empty, dipped, quarter, half, and level). Each child exhibited a different but orderly demand function of response (acceptance, expulsion, and mouth clean) by cost (increasing spoon volume) for a constant pay-off of toys and social interaction. In Experiment 2, physical guidance or nonremoval of the spoon for food refusal was initiated at the smallest spoon volume with low levels of acceptance, and was subsequently introduced at the largest spoon volume with moderate levels of acceptance. Treatment was effective in increasing acceptance, and these effects generalized hierarchically across untargeted spoon volumes. The results of both studies provide preliminary support that increasing spoon volume can be equated conceptually with increasing response effort, and that the change from differential reinforcement to physical guidance or nonremoval of the spoon appears to have altered the elasticity of each child's demand function.     

THE DEVELOPMENT OF CORRECT TOOTHBRUSHING TECHNIQUE IN PRESCHOOL CHILDREN

This study examined the effects of an intensive training program on the toothbrushing skills of three preschool children, using both performance measures and outcome (plaque level) indicators. Toothbrushing was broken into 16 steps that involved actual manipulation of the brush in the mouth. Correct brushing included four criteria: (a) appropriate angle of bristles, (b) appropriate motion of brush, (c) appropriate tooth surface, and (d) minimum duration of brushing. Training included instructions, a three-phase modeling procedure, physical guidance, and reinforcement. Results of a multiple baseline design across subjects showed that the children completed an average of 8.6% of the steps prior to training, as compared with an average of 95.8% of the steps following training. Plaque levels decreased from an average of 58% during baseline to 24.6% after training. Follow-up measures revealed that 86.6% of the steps were maintained. The study demonstrated that the effectiveness of the procedures in teaching very young children a complex motor skill that is essential to their future health.     

INTERTRIAL INTERVAL DURATION AND LEARNING IN AUTISTIC CHILDREN

This study investigated the influence of intertrial interval duration on the performance of autistic children during teaching situations. The children were taught under the same conditions existing in their regular programs, except that the length of time between trials was systematically manipulated. With both multiple baseline and repeated reversal designs, two lengths of intertrial interval were employed: short intervals with the S^D for any given trial presented approximately one second following the reinforcer for the previous trial versus long intervals with the S^D presented four or more seconds following the reinforcer for the previous trial. The results showed that: (1) the short intertrial intervals always produced higher levels of correct responding than the long intervals; and (2) there were improving trends in performance and rapid acquisition with the short intertrial intervals, in contrast to minimal or no change with the long intervals. The results are discussed in terms of utilizing information about child and task characteristics in terms of selecting optimal intervals. The data suggest that manipulations made between trials have a large influence on autistic children's learning.     

TREATMENT INTEGRITY IN APPLIED BEHAVIOR ANALYSIS WITH CHILDREN

Functional analysis of behavior depends upon accurate measurement of both independent and dependent variables. Quantifiable and controllable operations that demonstrate these functional relationships are necessary for a science of human behavior. Failure to implement independent variables with integrity threatens the internal and external validity of experiments. A review of all applied behavior analysis studies with children as subjects that have been published in the Journal of Applied Behavior Analysis between 1980 and 1990 found that approximately 16% of these studies measured the accuracy of independent variable implementation. Two thirds of these studies did not operationally define the components of the independent variable. Specific recommendations for improving the accuracy of independent variable implementation and for defining independent variables are discussed.     

ASSESSMENT AND TREATMENT OF CLINICAL FEARS IN MENTALLY RETARDED CHILDREN

Three moderately mentally retarded females ranging from 8 to 10 years of age were treated for long-standing fears. These children had refused to talk with or be in the same general vicinity of adults other than their parents, a few close family members, and to a lesser degree, their teacher. To establish an accurate criterion for successful performance on dependent measures, participants were matched on age, sex, and level of mental retardation with children having “normal” amounts of fear. Dependent measures included approaching and talking to strange adults as well as child ratings of overall fear. Participant modeling was given by the mother who provided a sufficient amount of physical and verbal prompts to ensure that an acceptable greeting of adults specified by the mother were made. These prompts were gradually faded out as treatment progressed. Treatment, which was given in a multiple baseline format across subjects, proved effective and gains in the reduction of fears were maintained at the six month follow-up.     

Developing positive social-emotional behaviors: a study of training and generalization effects

Four handicapped children were taught four positive social-emotional behaviors: smiling, sharing, positive physical contacting, and verbal complimenting, using instructions, modelling, and praise. Rates of these behaviors were shown to increase in four trained subjects using a within-subject multiple-baseline experimental design. The generality of the behavior change was investigated by integrating three untrained subjects with the trained subjects in a setting free of adult-imposed contingencies and through a series of follow-up observations. Three trained subjects evidenced collateral increases in the generalization setting on at least one other behavior when training in smiling was conducted. One trained subject showed generalization session increases for each behavior when training was conducted to increase that behavior. All three untrained subjects demonstrated increased rates of smiling and sharing when interventions were conducted to increase those behaviors with the trained subjects. There was no appreciable generalization of verbal complimenting by either the trained or the untrained subjects. Both trained and untrained subjects generally maintained their increased rates of smiling, sharing, and positive physical contacting across four weeks of follow-up observations.     

THE EFFECTS OF REARRANGING WARD ROUTINES ON COMMUNICATION AND EATING BEHAVIORS OF PSYCHOGERIATRIC PATIENTS

Several aspects of ward routine were changed to study the effects of environmental manipulation on the behavior of 21 psychogeriatric patients. Furniture was rearranged to be more conducive to conversation (i.e., grouped around tables instead of along corridor walls), and mealtime routines were changed to allow patients more time to eat, more freedom in choosing the composition of the meal, and more pleasant surroundings. Patients were divided into experimental and control groups, and data were collected on the frequency of verbal and tactile communication and degree of skill in eating behavior. Following baseline, environmental changes were introduced across behaviors. Results show that the frequency of communication increased for the experimental group, as compared to both baseline and the control group. Eating behavior also improved significantly for the experimental group. The study shows that minor changes in the physical environment can promote therapeutic change in the behavior of patients diagnosed as senile dementia.     

CONSUMPTION AND RESPONSE OUTPUT AS A FUNCTION OF UNIT PRICE: MANIPULATION OF COST AND BENEFIT COMPONENTS

We conducted preference assessments with 4 typically developing children to identify potential reinforcers and assessed the reinforcing efficacy of those stimuli. Next, we tested two predictions of economic theory: that overall consumption (reinforcers obtained) would decrease as the unit price (response requirement per reinforcer) increased and that the cost and benefit components that defined unit price would not influence overall consumption considerably when unit price values were equal. We tested these predictions by arranging unit price such that the denominator was one (e.g., two responses produced one reinforcer) or two (e.g., four responses produced two reinforcers). Results showed that consumption decreased as unit price increased and that unit price values with different components produced similar consumption.     

ASSESSING AND TRAINING TEACHERS IN THE GENERAUZED USE OF BEHAVIOR MODIFICATION WITH AUTISTIC CHILDREN1

This study investigated the feasibility of developing reliable, valid criteria for measuring and training the skills necessary to teach autistic children. The behaviors of 11 teachers and 12 autistic children were recorded in a series of different teaching situations. Teacher-training was initiated at different times for different teachers. The results showed: (1) it was possible to assess empirically whether a teacher was correctly using defined behavior-modification techniques; (2) generally, for any given session, systematic improvement in the child's behavior did not occur unless the teacher working in that session had been trained to use the techniques to a high criterion; (3) all 11 teachers were rapidly trained to use these techniques; and (4) the teachers learned generalized skills effective with a variety of children and target behaviors.     

A BRIEF COMPONENT ANALYSIS OF POTENTIAL TREATMENT PACKAGES IN AN OUTPATIENT CLINIC SETTING WITH YOUNG CHILDREN

The purpose of this study was to develop outpatient clinic assessments that allowed us to assess multiple treatment variables, produce relatively quick effects, and isolate active treatment components. Assessment began by evaluating a treatment package consisting of antecedent and consequence variables followed by a component analysis to determine the separate effects of the treatment variables. Three examples of the findings are presented.     

BEHAVIORAL ASSESSMENT AND TREATMENT OF CHRONIC FOOD REFUSAL IN HANDICAPPED CHILDREN

In this study, we examined the eating behavior of four handicapped children, none of whom exhibited self-feeding skills. All children had a history of food refusal and were nutritionally at risk; one child received all nourishment by way of a gastrostomy tube. Baseline data taken during mealtimes indicated that all children accepted very little food, expelled food frequently, and engaged in a number of disruptive behaviors. Treatments consisted of one or more of the following contingent events: social praise, access to preferred foods, brief periods of toy play, and forced feeding. Results of multiple-baseline and reversal designs showed marked behavioral improvement for each child and increases in the amount of food consumed. Further improvements were noted at follow-up, which ranged from 7 to 30 months posttreatment.     

SOME STRUCTURAL ASPECTS OF DEVIANT CHILD BEHAVIOR1

Covariation within behavior repertoires of problem children were examined. Two boys, referred for psychological help, were observed both at school and at home for about 3 yr. A coded observation system permitted scoring of 19 child-behavior categories and six social-environment categories. After a two-month baseline, behavior categories were intercorrelated, demonstrating that each child showed a group of behaviors that covaried. These groupings were specific to the home and school settings. Contingency management procedures were then applied to each child's problem behaviors in one setting. Next, a reversal phase was instituted, followed by resumption of the initial contingency management phase. These three phases lasted seven months, until the end of the children's public school terms. Results showed that the baseline group of covarying behaviors continued to covary over the three experimental phases. The children then entered a remedial education setting for three summer months, and then returned to schools and were observed in follow-up for 2 yr. The baseline group of behaviors continued to covary during both phases. The behavior covariations could not be accounted for on the basis of temporal relationships between the behaviors and social environment categories. Although no behavior covariations extended across either child's home and school settings, contingency management procedures produced across-setting effects.     

SOCIAL INFLUENCES ON “SELF-STIMULATORY” BEHAVIOR: ANALYSIS AND TREATMENT APPLICATION

We tested the hypothesis that the “self-stimulatory” behaviors exhibited by some individuals may be socially mediated. Four developmentally disabled children who exhibited hand flapping and body rocking participated in a series of three experiments conducted to assess the influence of social variables on stereotyped behavior and to develop a treatment based on the assessment. Experiment 1 used an assessment procedure to determine the relative influences of social attention and task demands on stereotyped behavior. For all four children, hand flapping and body rocking increased when difficult academic tasks were introduced. Experiment 2 involved the use of a procedural time-out and demonstrated that removing task demands contingent on stereotyped behavior resulted in increased rates of hand flapping and body rocking. In Experiment 3, these results were used to develop a communication treatment that consisted of teaching the children to request assistance on the difficult tasks. This treatment resulted in significant reductions in self-stimulatory behavior. These results are consistent with the hypothesis that some forms of repetitive stereotyped behavior may come to serve social functions (e.g., escape from aversive situations). Teaching a functionally equivalent communicative alternative to escape-motivated stereotyped behavior can be an effective form of intervention for this problem.