|
| International Symposium - Contemporary Issues in Stimulus equivalence: nodal distance, phonological interference and non arbitrary response options |
| Monday, May 29, 2006 |
| 3:00 PM–4:20 PM |
| Vinings |
| Area: VBC; Domain: Basic Research |
| Chair: Louise A. Mchugh (University of Wales, Swansea) |
| Abstract: A comprehensive understanding of equivalence relations is critical to a learnt account of language. In accord with this there is a wealth of empirical work being conducted in the analysis of equivalence relations. The papers in this symposium are a representation of some of the work in this area. The first two papers address a topical issue in the equivalence literature, that is, whether the variables responsible for nodal distance effects in equivalence classes are due to nodal distance itself (i.e. a structural network of connections) which causes differing degrees of relatedness among stimuli or whether it is due to the fact that stimuli receive differing degrees of reinforcement (i.e. a common history of reinforcement). Findings support the latter hypothesis. The third paper compares orthographic and phonological interference during stimulus equivalence with both normal and dyslexic participants. Results indicate that, for the dyslexic participants, the provision of incorrect comparisons that were orthographically and phonologically similar to samples during equivalence testing interfered with responding in accordance with equivalence relations. Finally, the last paper in the series investigates the issue of competing non-arbitrary relational response options during equivalence testing interfering with the emergence of equivalence. |
| |
| Examination of Nodal-Distance Effects in Equivalence Class Formation. |
| ROBERT WHELAN (University College, Dublin), Louise A. Mchugh (University of Wales, Swansea), Carla Thomas (University of Wales, Swansea), Ting Wang (University of Wales, Swansea) |
| Abstract: Eight undergraduates were trained on a series of conditional discrimination tasks with type of training, paced (serial) or massed (concurrent) as a between-subject variable. Four participants in each condition were trained and tested on two six-member equivalence classes. Emergent relations were categorized according to nodal distance (i.e. the number of stimuli across which transitivity would have to hold in order for the relation to emerge). In the paced condition, class appropriate responding was an inverse function of nodal distance. Interestingly, in the massed condition no effects of nodal distance emerged. The participants were then trained to “build” a different number of bricks (each spacebar press produced a brick on the screen) in the presence of the two C and D stimuli, respectively. In the response transfer test for the paced condition, nodal distance effects emerged relative to the responses trained to the C and D stimuli. However, for the massed condition, the A, B and E stimuli evoked responses similar responses trained to the C and D stimuli in the same class. The current findings counteract previous findings that the relatedness of stimuli in an equivalence class is a relatively permanent inverse function of nodal distance. |
| |
| Effects of Nodal Distance and Speed Contingencies on Equivalence Class Formation. |
| LOUISE A. MCHUGH (University of Wales, Swansea), Charlotte N. Dack (University of Wales, Swansea), Robert Whelan (University College, Dublin) |
| Abstract: This study compared performances on a series of conditional discrimination tasks with unequal or equal numbers of training trial types, and presence or absence of a speed contingency as between-subject variables. Sixteen undergraduates participated, four in each condition. Each of the participants was trained and tested on two five-member equivalence classes across eight training sessions. Response speed was an inverse function of nodal number with and without the speed contingency only in the unequal training trial types condition. There was a tendency for accuracy to peak during conditions without the speed contingency. The results of this experiment indicate that training across the eight sessions eliminated the effects of nodal distance within the equivalence classes. Implications for a relational operant, rather than a structural, account of derived relations are discussed. |
| |
| Further Research on Orthographic and Phonological Interference during Stimulus Equivalence Test Trials. |
| DENIS P. O'HORA (University of Ulster), Ian Thomas Tyndall (AMCD/National University of Ireland, Galway), Roisin Thompson (University of Ulster) |
| Abstract: Previous research (Tyndall & O’Hora, 2005) demonstrated that, for four dyslexic and four non-dyslexic individuals, the provision of incorrect comparisons that were orthographically and phonologically similar to samples during equivalence testing interfered with responding in accordance with equivalence relations. Similarly to this research, in both experiments in the current study, participants were provided with the training required to demonstrate four three-member equivalence classes consisting of real words and nonsense syllables. Experiment 1 replicated the work of Tyndall and O’Hora with a greater number of participants to test whether there were statistically significant differences in response latencies and errors across the four interference conditions. Experiment 2 employed the same four interference conditions during the equivalence test as Experiment 1 except that, instead of providing incorrect comparisons that were similar to the samples, the incorrect comparisons provided were similar to the correct comparisons. Findings are discussed in the context of current research in derived relational responding and have implications for the behavioral understanding of specific language impairments. |
| |
| Stimulus Equivalence, Transitivity & Non-Arbitrary Relations. |
| LORNA POWER (National University of Ireland, Galway), Ian T. Stewart (National University of Ireland, Galway) |
| Abstract: Previous research has shown that competing non-arbitrary relational response options during equivalence testing can interfere with the emergence of equivalence. Recent work has extended this analysis by showing that competing non-arbitrary relational options do not similarly affect symmetrical relational responding. The present study continues the analysis of this phenomenon by examining the effect of competing non-arbitrary relations on transitivity. Four groups of adult participants were exposed to three blocks each of training and testing for the formation of three 3-member equivalence relations. All four groups were trained using black and white stimuli. Group 1 participants were then immediately exposed to a color interference equivalence test in which the sample was always differently colored from the experimenter-designated ‘equivalent’ comparison, but was the same color as one of the non-equivalent comparisons, thus producing a conflict between arbitrary and non-arbitrary relational control. Group 2 received black and white transitivity testing before receiving two exposures to color equivalence testing. Group 3 received black and white transitivity and equivalence testing before color equivalence exposure while Group 4 received color transitivity testing before exposure to color equivalence tests. The results raised a number of issues for derived relational control, and these will be discussed. |
|
| |