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| Issues on the Emergence of Stimulus Control: Simple and Conditional Discrimination |
| Sunday, May 30, 2010 |
| 9:00 AM–10:20 AM |
| Lone Star Ballroom Salon E (Grand Hyatt) |
| Area: EAB; Domain: Experimental Analysis |
| Chair: Paula Ribeiro Braga-Kenyon (The New England Center for Children) |
| Discussant: Richard W. Serna (University of Massachusetts Medical Center) |
| CE Instructor: Daniel Moran, Ph.D. |
| Abstract: The current symposium raises several issues on the emergence of stimulus control. The first paper evaluated whether stimulus-stimulus relations (AB) could be established without differential reinforcement during acquisition, and assessed symmetry among these stimuli with typical humans. Results obtained were consistent with the hypothesis that stimulus-stimulus relations can be established in the absence of direct training involving differential consequences for correct responses. The second paper investigated whether typically developing children would promptly demonstrate the emergence of stimulus equivalence. Results indicated that basic language and naming skills may not be sufficient for the prompt emergence of stimulus equivalence, and that a history of performing such tasks under training conditions may contribute to the phenomenon. The final paper identifies training conditions under which temporal intervals that are signaled by different stimuli are memorized by rats and humans (i.e., the temporal control of the behavior is readily shown when the stimulus is presented). The results provide a basis for inferences about underlying cognitive mechanisms that determine memory storage and retrieval of humans and rats when trained on multiple discriminations that provide strategic information that can be used for effect teaching. |
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| Memorization Failure as a Function of Discrimination Difficulty and Training Sequences in Rats and Humans |
| PAULO GUILHARDI (The New England Center for Children), Marcelo S Caetano (Brown University), Marina Menez (Universidad Nacional de Mexico), Russell Church (Brown University) |
| Abstract: Our goal was to identify training conditions under which temporal intervals that are signaled by different stimuli are memorized (i.e., the temporal control of the behavior is readily shown when the stimulus is presented). Rats and humans were trained on three signaled temporal discriminations using either fixed-interval or peak procedures. The sequence of presentation of intervals (intermixed within a session, in blocks of trials within the session, or in blocks of sessions) and the difficulty of the discrimination (similarity across stimuli) were varied. Rats and humans memorized intervals when the temporal discriminations were intermixed within a session and when they occurred in blocks of trials within the session, the latter provided the stimulus discrimination was not difficult. Rats and humans, however, failed to memorize the temporal discriminations when they occurred in different sessions or in blocks of trials within the session, the latter provided the stimulus discrimination was difficult. The results provide a basis for inferences about underlying cognitive mechanisms that determine memory storage and retrieval of humans and rats when trained on multiple discriminations that provide strategic information that can be used for effect teaching. |
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| The Establishment of Stimulus-Stimulus Relations Without Differential Reinforcement |
| BARBARA S. MILLS (New England Center for Children), Maria Andrade (The New England Center for Children) |
| Abstract: The purpose of this study was to evaluate whether stimulus-stimulus relations (AB) could be established without differential reinforcement during acquisition, and to assess these relations for symmetry. Three typically developed individuals, ages 4 through 25 participated in this study. Participants were first presented with a series of matching to sample tasks using familiar stimuli, and accurate performance on these tasks was maintained without any differential consequences. Target stimulus-stimulus associations involving three pairs of visual arbitrary symbols were then introduced through sequences of matching to sample trials in which two random stimuli served as incorrect comparison (S-) in every trial. During this phase, the only response that could occur consistently across trials was towards the stimulus designated positive. Participants responded as expected in the absence of differential reinforcement of each selection (i.e. always choosing the stimulus that appeared consistently on the array). Changes in trial configuration were systematically and gradually carried out so that the random comparison stimuli were replaced by target stimuli belonging to the other association pairs. Results obtained are consistent with the hypothesis that stimulus-stimulus relations can be established in the absence of direct training involving differential consequences for correct responses. |
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| The Development of Stimulus Equivalence in Young Children |
| AMBER L. MANDLER (New England Center for Children), Maria Andrade (The New England Center for Children) |
| Abstract: The current study investigated if children at early stages of language development would promptly demonstrate the emergence of stimulus equivalence. Procedures were similar to the ones described by Schusterman and Kastak (1993) which found evidence of equivalence in sea lions. Three typically developed children, ages 3 to 5, participated in this experiment. Forty five visual stimuli were divided in 15 sets (1 through 15) containing three stimuli each (A, B, and C). All stimuli were previously unknown to the participants. Participants were directly trained to match stimuli A to stimuli B and stimuli B to stimuli C using three of the fifteen sets. After showing inconsistent results in transitivity and symmetry tests, participants were trained to perform the matching tasks corresponding to these properties. Once mastery criteria were met, three new sets of stimuli were introduced and the same training and testing sequence was implemented. Results indicate that the presence of basic language and naming skills may not be sufficient for the prompt emergence of stimulus equivalence, and that a history of performing such tasks under training conditions may contribute for the phenomenon. |
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