Controle de estímulos e formação de classes de estímulos equivalentes em crianças e em indivíduos com Síndrome de Down

Abstract

Two studies evaluated emergent stimulus-stimulus relations and selection and rejection controlling relations. Study 1 evaluated controlling relations after two types of conditional discrimination training: standard matching-to-sample (MTS) tasks and tasks using the blank comparison MTS. Participants were five preschool children and two adults and one child with Down syndrome. Two conditions were employed. Condition I involved standard twocomparisons MTS. Condition 2 used mask procedure (or blank comparison procedure) to produce select and reject relations. Both conditions trained AB and BC relations, assessed emergent relations AC and CA and employed new stimulus probes to assess selection and rejection controlling relations in each taught conditional discrimination. Condition 2 also evaluated stimulus class expansion after teaching CD. All participants showed one-node emergent relations. Seven showed class expansion. However, some participants showed positive results for equivalence immediately, others, delayed emergence or yet only after resumption of training with new sets of stimuli. New stimulus probes results showed variability initially, possibly indicating experience with the task as important variable. Novelty control predominated in some cases. Study 2 assessed whether employing new stimulus probes at different stages of the procedure (after conditional discrimination training or after tests for emergent relations) would produce different patterns of responding. Six children were taught two sets of conditional discriminations (BC / AB and EF / ED, in that order). Half of the participants had new stimulus probes after each trained relation for the first stimulus set and after equivalence tests for the second set of stimuli. The other half of participants had this order reversed. Three participants showed equivalence for both sets of stimuli. The stage of new stimulus probes application did not alter the probe results. Taken together, the results of both studies suggest that performance on new stimuli probes is not related to performance on tests for equivalence class formation.