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| The Emergence of Stimulus Classes: Discrimination of Components in Compound Stimuli and the Role of Class-Specific Reinforcement |
| Saturday, May 23, 2009 |
| 3:30 PM–4:50 PM |
| North 125 |
| Area: AUT/EDC; Domain: Applied Behavior Analysis |
| Chair: Kathy Clark (The New England Center for Children) |
| Discussant: Richard W. Serna (University of Massachusetts Medical School - Shriver Center) |
| CE Instructor: Rachel S.F. Tarbox, Ph.D. |
| Abstract: Over the years, matching-to-sample (MTS) procedures have been widely used in the stimulus equivalence literature. More recently, novel procedures and variations of typical MTS have been investigated. These may include MTS with class specific reinforcement, multiple-exemplar training, and discrimination training with compound stimuli. The current symposium will focus on the use of these procedural variations. The first study produced expansion of stimulus classes via class-specific reinforcement which suggests that conditioned and generalized reinforcers can become members of these classes. In the second study, a go/no-go procedure with spatially contiguous pairs of figures presented on a computer screen was used to produce emergent relations. Results suggested some advantages of the go/no-go procedure over matching-to-sample. In the third study, participants learned to respond to small verbal unit-components using multiple-exemplar training. Results suggest that participants acquired re-combinative reading immediately after training. Combined, these studies suggest alternative ways to generate stimulus classes and emergent responding. |
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| Class-specific Reinforcement and the Establishment of Equivalence Classes |
| CAMMARIE JOHNSON (The New England Center for Children), Olga Meleshkevich (The New England Center for Children and RCS Learning Center) |
| Abstract: This study examined the expansion of stimulus classes via class-specific reinforcement. Three typical adults learned conditional discriminations (AC, BC, and DF, EF) with match-to-sample procedures. Equivalence classes were then shown within two groups, each consisting of 3 three-member sets of nonrepresentational visual stimuli (A1B1C1, A2B2C2, A3B3C3 and D1E1F1, D2E2F2, D3E3F3). Throughout training, correct selection of A1, B1, C1 and D1, E1, F1 was always followed by reinforcers, r1/R1; correct selection of A2, B2, C2 and D2, E2, F2 was always followed by reinforcers, r2/R2, and those of A3, B3, C3 and D3, E3, F3 were always followed by reinforcers, r3/R3. None of the stimuli from ABC classes ever appeared on reinforced conditional discrimination trials with stimuli from DEF classes; however, for 2 of 3 participants 3, 6-member classes (e.g., A1B1C1D1E1F1) emerged. Moreover, tests for these 2 participants indicated that the class-specific reinforcers were also class members, thereby demonstrating 3 classes each with 8 members (e.g., A1B1C1D1E1F1r1R1). One implication from this study is the possible generation of equivalence classes with class-specific reinforcement. A second implication is that both conditioned and generalized reinforcers can become members of these classes. |
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| Emergent Conditional Relations In A Go/No-Go Procedure: Figure-Ground and Stimulus-Position Compound Relations |
| PAULA DEBERT (University of Sao Paulo - Brazil), Edson Huziwara (Universidade de São Paulo), Robson Faggiani (USP), Maria Eugênia Simões De Mathis (University of São Paulo and University of Massachusetts Medical School), William J. McIlvane (University of Massachusetts Medical School) |
| Abstract: Past research has demonstrated emergent conditional relations using a go/no-go procedure with spatially contiguous pairs of figures presented on a computer screen. During training, each two-component stimulus was presented successively. Responses emitted in the presence of certain stimulus pairs (A1B1, A2B2, A3B3, B1C1, B2C2 and B3C3) were reinforced, whereas responses emitted in the presence of other pairs (A1B2, A1B3, A2B1, A2B3, A3B1, A3B2, B1C2, B1C3, B2C1, B2C3, B3C1 and B3C2) were not. During tests, new configurations (BA, CB, AC, and CA) were presented. The present study evaluated whether emergent relations would be established with this procedure addressing particularly situations in which the use of matching-to-sample is procedurally cumbersome or impossible. In Experiment 1, we evaluated whether emergent relations would be established when two-component stimuli were displayed as figure-ground (abstract figure displayed on colored background). Five adults showed emergent relations consistent with stimulus equivalence during testing. In Experiment 2, the two-component stimulus was a figure and its location (left or right). Six adults exhibited emergent relations. Thus, both experiments show that the go/no-go procedure with two-component has some advantages as an alternative to matching-to-sample to establish emergent relation when training involves stimuli of the type employed in the present experiments. |
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| The Process of Discriminating Minimal Verbal Units in Reading |
| MARTHA HÜBNER (USP Sao Paulo, Brazil), Leila Bagaiolo (Gradual/USP) |
| Abstract: The current study investigated what has been called re-combinative reading. In other words, reading under the control of minimal verbal units involving the discrimination of the components of a compound stimulus (words). This behavior has been investigated within the equivalence paradigm (to establish reading with comprehension) and via generalization probes consisting of new words formed by syllables and letters from the learned set of words. Participants were typically developing preschool children. Training involved teaching participants to respond to the smaller verbal units using a multiple-exemplar procedure. Results indicated that participants acquired re-combinative reading during training and not during probe sessions since responses during the first probes were always correct. It was also observed that most errors occurred 1) in the presence of compound stimuli in which components topographically resembled each other and 2) when different sequences produced similar vocal responses. |
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