Joseph E. Spradlin

The development of stimulus classes using match-to-sample procedures: Sample classification versus comparison classification☆

Abstract Four experiments were conducted to investigate the development of stimulus classes using matching-to-sample procedures. The first three experiments involved teaching subjects to select four different comparison stimuli in response to a single sample stimulus. In the fourth experiment, the subjects were taught to select a single comparison stimulus in response to four different sample stimuli. Only one of the six subjects who received single-sample, multiple-comparison training demonstrated stimulus class development. All three subjects who were given training in selecting a single comparison stimulus in response to multiple samples demonstrated stimulus class development.

An Interaction of Instructions and Training Design on Stimulus Class Formation: Extending the Analysis of Equivalence

Our previous research with subjects with mild mental retardation indicated different outcomes on stimulus equivalence tests when different training designs were employed. Subjects exposed to match-to-sample training involving four pairs of sample stimuli and one pair of comparisons (comparison as node) were more likely to show positive results on equivalence tests than subjects trained with four pairs of comparisons and one pair of samples (sample as node). We describe three studies aimed at analyzing the superiority of the comparison-as-node training procedure. The results suggest that (a) preexperimental individual differences and subject assignment do not account for the previous findings, (b) the greater effectiveness of the comparison-as-node procedure may be caused partially by an interaction of the procedure and instructions providing stimulus names, and (c) differential outcomes on equivalence tests with these training procedures may be demonstrated only with developmentally limited subjects. Several theoretical interpretations for the reason the comparison-as-node training method is more likely to produce positive equivalence test performances and the implication of these interpretations for understanding stimulus equivalence in general are discussed.

The Behavior of Moderately and Severely Retarded Persons1

Publisher Summary This chapter discusses the behavior of retardates who score below IQ 50 on a standardized test. Severely retarded persons, especially those in residential centers, most frequently do not dress themselves, are not totally toilet trained, and in many instances do not even feed themselves. Their social reactions to people vary a great deal. The chapter provides the solution of practical problems through the use of operant techniques. The social reactions of moderately retarded children to adults are somewhat more varied than those of the severely retarded, and they usually exhibit a more extensive verbal repertoire. In cases where operant techniques are applied, the reported results are encouraging. Thus, it may be expected that these advances will lead to the development of training and educational programs, which one day will allow these people to live in and contribute to the noninstitutional community. The extent to which such a goal is accomplished depends primarily on the ingenuity and effort of interested workers.

Stimulus properties of reinforcement during extinction of a free operant response

Abstract Six moderately retarded adolescent girls were conditioned to respond at high stable rates for 4 consecutive days on a fixed ratio 50 schedule. They were then placed on extinction until they met a variable pause criterion for not responding. They were then delivered free reinforcement. The first time that free reinforcement was delivered there was an immediate resumption of responding by all six Ss. The effect ranged from a transitory effect lasting for only one reinforcement presentation to a rather permanent effect showing no decrease after more than 100 reinforcement presentations.

6 Derived stimulus control: Are there differences among procedures and processes?*

Publisher Summary The chapter describes procedures to demonstrate derived stimulus control and to classify them based on structure. It discusses the relationship among the various training structures and the likelihood of demonstrating stimulus classes in humans and animals. It also notes procedural differences that might affect the likelihood of demonstrating derived stimulus control within a particular training structure. There is more than one type of transfer involved in the stimulus class literature, and some species are limited to unidirectional transfer that essentially involves the recombination of chains: Pigeons demonstrate unidirectional transfer that may not involve symmetry or transitivity. They also demonstrate transfer that can be mediated by behaviors that occur between the presentation of the sample stimulus and the response to the comparison stimulus. Moreover, such intervening behaviors play different roles for pigeons than for human subjects. Pigeons are yet to demonstrate nonmediated symmetry or equivalence.

Establishing Stimulus Equivalences among Retarded Adolescents.

Abstract Two separate sets of stimuli were established as stimulus classes in a match-to-sample task by using each stimulus as both a sample and choice stimulus for every other member within that set. After classes were established, the subjects were taught to select one member of each class when an associated auditory stimulus was presented. After this training, three of six subjects were able to select the remaining members of each stimulus class in response to the appropriate auditory stimuli without direct training. The other three subjects also demonstrated transfer after additional members of each stimulus class were brought under the control of the auditory stimuli through direct training.

LEARNING-SET OUTCOME IN SECOND-ORDER CONDITIONAL DISCRIMINATIONS

This study was designed to determine whether the acquisition of second-order conditional discriminations becomes more rapid across new discriminations. Three normal grade-school children served as subjects. In general, performances improved across sets of second-order discriminations. Moreover, there was little disruption of performance when the second-order stimuli were changed from discrete forms to being compounded with the sample stimuli. Errors increased markedly when the second-order conditional discrimination shifted from one in which one secondorder conditional stimulus indicated that the original contingencies were reversed to a condition in which one second-order conditional stimulus indicated that the subject should select the same comparison stimulus regardless of which sample form was present. Errors prior to mastery decreased, however, across problems of the new type—thus reproducing the learning—set outcome with new stimuli.

A conceptual analysis of request teaching procedures for individuals with severely limited verbal repertoires.

There have been many published reports of attempts to teach requests to individuals with severely limited verbal repertoires associated with developmental disabilities. Few of these studies used Skinner’s (1957) term mand to refer to the behavior taught, yet many seemed to be influenced by Skinner’s analysis. We analyzed procedures according to three variables: motivational conditions, supplemental stimulation, and consequences. Individuals with severely limited verbal repertoires provide unique opportunities to study how each of these three variables influence the acquisition of requests. Our analysis indicated that several different procedures were effective in teaching requests, however the degree of supplemental stimulation for the requests varied greatly. Future request teaching programs should consider how each of these three variables influences targeted responses as well as how these variables influence generalization from teaching contexts to nonteaching contexts.

Reinstatement of an Operant Response by the Delivery of Reinforcement during Extinction.

Abstract Twelve severely retarded children were conditioned to respond at stable rates for 4 consecutive days on a fixed-ratio schedule. They were then given a single extinction session. The extinction session lasted until they had met a 2-minute pause criterion 15 times. On five of the occasions after the Ss met the pause criterion, they were delivered reinforcement; on five other occasions a buzzer sounded; and on another five occasions no change in the environment occurred (control). The Ss made more responses after reinforcement than after the buzzer or after the control.

Fixed ratio and fixed interval behavior of severely and profoundly retarded subjects

Abstract Profoundly and severely retarded S s were studied with operant conditioning procedures. Through shaping techniques, an operant knob-pulling response was established by 15 profoundly and severely retarded S s. The S s showed rather typical fixed ratio behavior with high rates of responding and with pauses after reinforcement. Mild deprivation increased the number of responses per session for two S s. For a third S a change in reinforcer increased the number of responses. Fixed interval schedules yielded low rates of responding with some evidence of temporal discrimination.