Richard R. Saunders

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.

Evidence of contingency awareness in people with profound multiple impairments: response duration versus response rate indicators.

Evidence of contingency awareness in people with profound multiple impairments is often elusive due to numerous variables that impede learning and contribute to performance variability. Recent research has shown that measuring duration of responding rather than rate has promise for more accurate inferences. Duration measures of adaptive-switch use were obtained with 50 participants during empirical tests for contingency awareness. Nearly 80% had test performance patterns indicative of cause-and-effect learning or contingency awareness. Rate data were obtained concurrent with duration measures for 33/50 participants. Although statistical analysis indicated an interaction of test condition and rate of responding, the performance pattern indicative of contingency awareness was observed in only about 50% of the sets of rate data. Further, rate-based indications of contingency awareness were not consistently confirmed by the duration data. The results strongly support inclusion of response duration measures in evaluation of adaptive-switch use and contingency awareness.

Equivalence Class Establishment with Two-, Three-, and Four-Choice Matching to Sample by Senior Citizens

In Experiment 1, 12 senior citizens from the community were trained with 18 sets of conditional discriminations. Training included 2-, 3-, and 4-choice matching-to-sample (MTS) configurations in linear series (LS), many-to-one (MTO), and one-to-many (OTM) training structures. Training structure order was counterbalanced across participants. The design permitted tests for class establishment ranging from 2 classes of 3 stimuli each to 4 classes of 4 stimuli each in the LS, MTO, and OTM structures. The experiment tested the hypothesis that 3- and 4-choice MTS would increase the probability of class establishment, relative to 2-choice MTS, by reducing the potential for sample/S- control to arise during training. Results showed, however, that training with 3- and 4-choice MTS did not significantly increase equivalence class establishment and unequivocal evidence of sample/S- control was found in only 1 instance of a 2-choice training and testing structure. Experiment 2 systematically replicated Experiment 1 with 6 additional senior citizens in a O-s delayed MTS paradigm. As in Experiment 1, equivalence class establishment was not related to number of choice stimuli. The delayed MTS paradigm, however, required fewer training trials to establish the conditional relations and led to more class establishment overall. The results are compared to data from previous studies with younger and older participants.

Evaluation of an Approach to Weight Loss in Adults with Intellectual or Developmental Disabilities.

Of 79 overweight adults with intellectual or developmental disabilities who participated in a weight loss intervention, 73 completed the 6-month diet phase. The emphasis in the intervention was consumption of high volume, low calorie foods and beverages, including meal-replacement shakes. Lower calorie frozen entrees were recommended to control portion size. A walking activity was encouraged. Participants attended monthly meetings in which a small amount of cash was exchanged for self-recorded intake and exercise records completed on picture-based forms. Average weight loss was 13.2 pounds (6.3%) of baseline weight at 6 months, with weight loss shown by 64 of the 73 individuals enrolled. Those completing a 6-month follow-up phase showed weight loss of 9.4% of baseline. Increased choice and control are discussed as possible contributors to individual success.

Increasing the Probability of Stimulus Equivalence with Adults with Mild Mental Retardation

In Experiment 1, 6 adults with mild mental retardation were taught 3 overlapping conditional discriminations in a linear series structure, establishing the possibility of the emergence of 2 stimulus equivalence classes of 4 stimuli per class. Training employed balanced trial types in which the discriminative stimuli were presented in fixed pairs across conditional discriminations (e.g., 81 and 82, C1 and C2). No participant.showed the emergence of equivalence classes in initial testing; 1 participant showed the establishment of classes with repeated testing, including tests for symmetry alone. In Experiment 2, 6 additional adults with mild mental retardation were similarly trained, with one methodological modification: Prior to testing, each comparison stimulus (e.g., 81) was presented in some trials with every stimulus from the opposing class (i.e., A2, 82, C2, and D2). With this modification, 4 of 6 participants showed the establishment of equivalence classes during initial testing. The results support hypotheses about the essential role of simple discrimination acquisition in equivalence class establishment.

Teaching Manual Signs to Adults With Mental Retardation Using Matching-to-Sample Procedures and Stimulus Equivalence

The objective of this study was to teach manual signs through an automated matching-to-sample procedure and to test for the emergence of new conditional relations and imitative behaviors. Seven adults with mild to severe mental retardation participated. Four were also hearing impaired. Relations between manual signs (set A) and pictures (set B) were initially taught, followed by the training of corresponding printed words (set C) and pictures (set B). Further presentations of conditional discriminations tested for the emergence of AC, followed by tests for the emergence of imitative signing behavior (D) in the presence of either pictures (B) or printed words (C). Each stimulus set was comprised of 9 elements. The stimuli were still pictures, printed words, and dynamic presentations of manual signs. A pretest was conducted to determine which signs the participants could make pre-experimentally. Teaching was arranged in a multiple baseline design across 3 groups of 3 words each.The purpose of the present study was to determine whether participants would emit manual signs in expressive signs tests as a result of observation (video modeling) during match-to-sample training in the absence of explicit training. Five of the 7 subjects passed tests of emergence and emitted at least 50% of the signs. Two were hearing impaired with signing experience, and 3 were not hearing impaired and had no signing experience. Thus, observation of video recorded manual signs in a matching-to-sample training procedure was effective at establishing some signs by adults with mental retardation.

Discovering indices of contingency awareness in adults with multiple profound disabilities

We conducted two studies to examine parameters of social attention in contingency awareness training using switch activation with individuals who had multiple profound disabilities. In Study 1 we compared leisure devices and social attention as reinforcing stimuli with 5 individuals. Results indicated the reinforcing qualities of social attention over leisure devices with 2 individuals and documented the importance of session length in training. In Study 2 we investigated idiosyncratic behaviors as indicators of responsiveness with 3 of the 5 original participants as they activated switches. Behavior changes during switch activation versus nonactivation times in the leisure device and social attention conditions suggested volitional movement supporting contingency awareness and preference. Implications for clinical practice are discussed.

THE REDUCTION OF SELF INJURY IN TWO ADOLESCENTS WITH PROFOUND RETARDATION BY THE ESTABLISHMENT OF A SUPPORTED ROUTINE

Two experiments applied a conceptualization of competence to the treatment of self injury in two adolescents with profound retardation. In Experiment 1, a multiple baseline design across two activity periods was used to assess the effects of reinforcing completion of a five-step packaging routine on repetitious facial hitting in one participant. The rate of facial hits decreased when teachers reduced the latency between a pause by the participant and a prompt from the teacher to continue, pauses having been observed to be followed often by sequence errors, and sequence errors by facial hitting. In Experiment 2, a reversal design was used to compare the effects on head hitting and hand biting by substituting a premeal and dining routine in a second participant. The new routine replaced a largely instructional routine that required discriminations, receptive language, and motor performances not likely to emerge in the participants repertoire. Discontinuation of the instructional routine reduced self injury; institution of the new routine permitted the development of a highly independent series of performances without reoccurrence of self injury. The combined results of the two experiments point to the potentially evocative nature of common teaching approaches and techniques, and the habilitative effects of designing performance expectations with greater prognosis for acquisition.

Transfer of matching and mismatching behavior in preschool children

Abstract Preschool children were trained to respond to choice stimuli which matched or did not match three different sample stimuli. Periodically, a fourth sample stimulus was employed as a probe to evaluate the transfer effects of the training operations. Neither matching nor mismatching responses to the probe samples were directly trained. When children were trained to match the three sample stimuli, they matched the probe sample; when the same children were trained to mismatch the three sample stimuli, they mismatched the probe sample. The transfer effects obtained on the matching-to-sample task appeared similar to recent findings of research on imitation.