Pieter C. Duker

The Motivation Assessment Scale: reliability and construct validity across three topographies of behavior.

The psychometric properties of the Motivation Assessment Scale (MAS) were examined. Specifically, reliability, internal consistency, and construct validity were estimated using 90 ratings of different problem behaviors among 86 individuals with mental retardation. Data were analyzed under conditions of (a) three topographies of problem behavior and (b) two methods of calculation. Although reliability and internal consistency were generally poor, the results depended upon the above conditions. Factor analysis revealed that the four factors of the MAS differed from the subscale structure obtained in this study, proposed by the authors of the MAS. Thus, the construct validity of this scale was ambiguous. It is concluded that the MAS should be employed in conjunction with other instruments to assess the functional characteristics of problem behavior with individuals who have mental retardation.

Communicative functioning in individuals with Angelman syndrome: a comparative study

Purpose: To assess expressive communication in individuals with Angelman syndrome. Method: Communicative functioning of individuals with Angelman syndrome (AS) (n = 109) was compared with individuals with mixed etiologies (n = 117) using the Verbal Behaviour Assessment Scale (VerBAS). Results: Within-group analyses of those with AS revealed that the communicative function of manding was significantly more developed than tacting and echoing, and that tacting was significantly more developed than echoing. Low mean total VerBAS-scores were found with individuals who had epilepsy and used anticonvulsant medication, and with those who had profound developmental disabilities. In the comparison group, the function of manding was significantly more developed than both tacting and echoing, while tacting did not differ from echoing. Between-groups analyses revealed that individuals with AS had significantly lower scores on tacting and echoing, but not on manding. Conclusion: The overall pattern of VerBAS scores for individuals with AS suggests a possible communicative phenotype.

Elimination of vomiting in a retarded female using restitutional overcorrection

A successful treatment of vomiting behavior is realized through application of restitutional overcorrection in a 19-year-old profoundly retarded female. Methodological control guarantees the internal validity of this treatment.

Effects of redesigning the physical environment on self-stimulation and on-task behavior in three autistic-type developmentally disabled individuals

A study was conducted to assess the effects of redesigning the physical environment (i.e., the classroom) on the occurrence of self-stimulation, ontask behavior, inappropriate behavior, and inactivity. Three developmentally disabled males, diagnosed as autistic-type, participated. Data were collected using a withdrawal design. Results showed a decrease of self-stimulation and inactivity and an increase of on-task behavior. Inappropriate behavior remained unchanged across experimental conditions.

A quasi-experimental study on the effect of electrical aversion treatment on imposed mechanical restraint for severe self-injurious behavior

Eight individuals with mental retardation and imposed mechanical restraints due to severe, life-threatening self-injurious behavior received electrical aversive treatment. Eight other individuals, who had been matched with the treatment group in terms of the degree of imposed mechanical restraint due to the above problem behavior, had not received electrical aversion treatment. A comparison of imposed mechanical restraint scores, as a measure of severity of self-injurious behavior, between both groups over a period of three years, revealed that electrical aversion treatment significantly reduces the degree of imposed mechanical restraint.

Cross-setting generalization of manual signs to verbal instructions with severely retarded children

This study assessed the effects of a procedure of transfer of stimulus control on the cross-setting generalization of manual signs with three severely retarded children. The procedure was designed in order to have the subjects perform appropriate signs to verbal instructions. The dependent variables consisted of manual sign responses at probe sessions in the classroom and on the ward to assess generalization of training across settings and persons, as well as the percentage correct verbal imitations of instructions used during training. The results, gathered within a multiple baseline design across responses show that: Performance of manual signs to verbal instructions generalized across settings, yet acquired signs did not facilitate Ss production of the appropriate referent within a verbal imitation paradigm. The importance of choosing appropriate signs is emphasized.

Long-Term Use of Electrical Aversion Treatment With Self-Injurious Behavior

Twelve severely and profoundly mentally retarded individuals with life-threatening self-injurious behaviors were exposed to electrical aversion treatment using a remotely controlled device. Long-term effectiveness was assessed for periods ranging from 2 to 47 months for the 12 individuals, respectively. The degree of imposed physical restraint was used as the major dependent variable. With two individuals, the treatment failed to suppress self-injurious behavior. With seven individuals, however, suppression was nearly complete in that physical restraints were no longer necessary. With three individuals moderate effects were obtained, in that, although a substantial decrease of imposed physical restraint had been achieved, they still needed daily administrations of electrical aversive stimuli. The results are discussed in terms of the practical application of this procedure.

Treatment of food refusal by the overcorrective functional movement training method

Abstract A procedure involving overcorrective functional movement training was used in the treatment of severe food refusal by a severely retarded, quadriplegic boy. The effect of the treatment was validated through an ABAB design. The dependent variables of the procedure were the number of overcorrection trials and the cubic centimeters of food intake. Follow-up measures are reported at 4 and 6 months.

The use of negative practice for the control of pica behavior.

The treatment of a 33-year-old female disabled by mental retardation and Prader-Willi syndrome who exhibited pica is described. Negative practice was administered following each occurrence of the target behavior, that is, biting off and chewing on inedible objects. Data were collected within a reversal design. The results indicated that pica was reduced to a near zero level. Follow-up data collected after 7 months while the procedure was continued revealed a sustained suppression of pica.

Acquisition and Generalization of Social Behaviors in Language-Disabled Deaf Children.

In the present study, the effectiveness of a multifaceted training package on the acquisition and generalization of three social behaviors—initiating interaction, interacting with others, and turn waiting—was assessed with nine 12- and 13-year-old language-disabled deaf children. The package included (1) child training and (2) supervision, feedback, and goal-setting by teachers and residential staff members. Steps were taken to promote generality of the effects and the social validity of the procedures. Data were collected within a multiple baseline design across behaviors. Visual inspection and statistical analysis showed that instances of appropriate target behaviors increased and were generalized across settings, activities, and subjects during the training procedure and that the effects were maintained following training.