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| International Symposium - Experimental Investigations of Equivalence Classes |
| Sunday, May 28, 2006 |
| 10:30 AM–11:50 AM |
| International Ballroom South |
| Area: EAB; Domain: Basic Research |
| Chair: Jeffrey J. Everly (West Virginia University) |
| Abstract: The four papers in this symposium are experimental investigations of equivalence classes. The paper by Lobo et al. deals with effects of different types of instructions on class formation. Alligood and Chase examined the variability of responding to stimuli within established equivalence classes. Groskreutz et al. employed complex sample stimuli in pre-class-formation match-to-sample training. Finally, Sighvatsson and Sigurdardottir examined the relation between equivalence and naming in subjects with Broca's Aphasia. |
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| Comparing Effects of Multiple-Exemplar Tactical Instructions and Referential Instructions on Equivalence-Class Formation. |
| HAROLD E. LOBO (West Virginia University), Philip N. Chase (West Virginia University), Chata A. Dickson (West Virginia University) |
| Abstract: This presentation deals with effects of two types of instructions on performance during tests for the properties of stimulus equivalence. Female undergraduate students completed a linear-series baseline training procedure that was expected to establish three equivalence classes of five members each. Subjects with deficient performance during tests for emergent relations were randomly presented with either one of two types of instructions. Half of the subjects were presented with an extended set of multiple-exemplar tactical instructions; whereas the remaining subjects were presented with referential instructions. Multiple-exemplar tactical instructions describe a pattern of responding that efficiently produces correct responses by presenting multiple exemplars of baseline conditional discriminations and emergent relations. Referential instructions impact correct responding by describing the relation between baseline and emergent conditional discriminations. Further testing on emergent relations followed instructional training. Results are discussed in the context of previous findings suggesting that equivalence-class formation is facilitated by presenting subjects with a strategy that describes the principle of equivalence. Implications of multiple-exemplar tactical and referential instructions for our understanding of concept learning and behavioral effects of specific instructions also are discussed. |
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| Choice Among Stimuli in Equivalence Classes. |
| CHRISTY A. ALLIGOOD (West Virginia University), Philip N. Chase (West Virginia University) |
| Abstract: Variability in responding to stimuli within equivalence classes has been of interest to researchers for several years. One way of investigating variability is to test the effect of nodal number, or the number of nodes involved in a relation. Previous research suggests that nodal number is related to variability in responding to stimuli in equivalence classes such that subjects respond more quickly and more accurately on relations involving fewer nodes. The present research used post-class-formation tests of within-class preference to further test the parameters of this variability. Subjects more frequently chose comparisons related to the sample via fewer nodes than those related via more nodes. In addition, subjects chose comparisons related to the subject via symmetry as often or more often than those related via trained baseline relations. These results have implications for theory, including the substitutability of stimuli in equivalence classes, and for practice, including fluency-based instruction. |
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| The Effects of Using Complex Auditory-Visual Samples on Equivalence Class Formation. |
| NICOLE GROSKREUTZ (New England Center for Children), Allen J. Karsina (New England Center for Children), Caio F. Miguel (New England Center for Children), Mark P. Groskreutz (New England Center for Children) |
| Abstract: When complex stimuli are presented together as samples in matching-to-sample training, it is possible that one element is more salient than the other. The purpose of Experiment 1 was to evaluate the effects of simultaneously presenting both an auditory and visual sample stimulus during matching-to-sample training. Participants were 6 individuals diagnosed with autism spectrum disorder. The complex samples consisted of an auditory stimulus in the form of spoken words (A) and a visual stimulus in the form of line drawings or pictures (B). A second set of visual stimuli in the form of written words (C) served as comparisons. Pre- and post-tests were conducted on AB, AC, BC, CB, and oral naming (BD, CD). All participants acquired the tested relations suggesting the absence of restricted stimulus control. Experiment 2 attempted to produce restricted stimulus control by exposing the participants to a visual-visual conditional discrimination prior to training with the complex sample. Participants were 2 of the individuals exposed to Exp 1. Preliminary results indicate, at least for 1 participant, that prior exposure to the visual-visual matching-to-sample prevented the establishment of control by the auditory component of the complex sample. |
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| Establishing Stimulus-equivalence Classes in Patientswith chronic Broca’s aphasia: Does it improve naming? |
| MAGNUS SIGHVATSSON BLONDAHL (University of Iceland), Z. Gabriela Sigurdardottir (University of Iceland) |
| Abstract: For over 30 years the work of Sidman and colleagues (Sidman, 1971; Sidman, Stoddard, Mohr & Leicester, 1971; Mohr, Sidman, Stoddard, Leicester, & Rosenberger, 1973) has been known as the experiments that later resulted in the stimulus equivalence paradigm. Unfortunately, replications of those early experiments with Broca’s aphasia patients have been few or nonexistent. Based on the pre-experimental work from the early 1970s, the presence of several stimulus-stimulus relations were measured in four adults suffering from chronic Broca’s aphasia. In a four-choice, table-top, matching-to-sample task, our tests measured the following stimulus-stimulus relations: visual-visual, tactile-tactile, auditory-visual, auditory-tactile, tactile-visual and visual-tactile. Moreover, participants’ ability to name the correct comparison stimuli and to imitate an auditory sample in the presence or absense of its corresponding visual stimulus were tested. Experimental stimuli in this study were letters from the Icelandic alphabet, a total of 36 different stimuli. Results indicate that all subjects had trouble performing correctly in the auditory-visual matching task and some of them also had problems in the auditory-tactile matching task. Conditional discrimination training in auditory-visual matching is in progress in the hope of improving the participants’ performances in naming. |
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