The experiment was an attempt to gain a more precise understanding of the temporal relation between the development of analytic units and equivalence relations. Two prompting procedures were used during training to pinpoint when eight subjects learned the conditional discriminations. Near simultaneous presentation of probe and training trials allowed for examination of the temporal relation between conditional discrimination acquisition and derived performances on stimulus equivalence probes. The data show that, for seven of eight subjects, a decreased reliance on prompts was coincident with the development of equivalence-consistent choices on either all or some probe trials, which suggests that the development of analytic units is sufficient to give rise to equivalence relations among stimuli.

A intervenção no cérebro e a possível influência no responder dos organismos têm sido alvo de diversas pesquisas que visam analisar tal relação. Deste modo, o presente estudo busca fornecer indicadores dos possíveis efeitos do fechamento das suturas cranianas sobre a aprendizagem discriminativa em esquemas de reforçamento. Para isso, serviram como sujeitos quatro ratos cirurgicamente intactos e nove submetidos a diferentes procedimentos cirúrgicos para o fechamento das suturas cranianas. Os sujeitos, com idades entre dois e oito dias de vida, foram submetidos a quatro fases experimentais em caixas de condicionamento operante. Na primeira fase, respostas de pressão à barra foram modeladas e, na seqüência, 60 respostas foram reforçadas em esquema de reforçamento contínuo (CRF) por três sessões consecutivas. Na segunda fase, o esquema de CRF foi substituído por esquemas de intervalos fixos (FI) com três valores aumentados gradualmente (FI 4 s, FI 8 s e FI 11 s). Na terceira fase, os sujeitos foram submetidos a um esquema múltiplo composto pelos componentes FI 11 s e Extinção (EXT), na presença e ausência de luz, respectivamente. Este treino discriminativo foi mantido até que ao menos 80% das pressões à barra ocorressem nos componentes de FI. Finalmente, na quarta fase, houve uma reversão das funções dos estímulos, de modo que a presença e a ausência de luz passaram a acompanhar, respectivamente, os componentes de EXT e FI. De modo geral, os resultados revelaram que os procedimentos empregados na constrição do desenvolvimento cerebral não produziram efeitos evidentes no comportamento dos ratos sob esquema de reforçamento, assim como na aprendizagem discriminativa e sua reversão / The intervention in the brain and the possible influence on the response of organisms has been the subject of several studies designed to examine this correlation. The aim of the present study is to provide indicators of the possible effects of the cranial sutures closure to the discriminative learning in reinforcement procedures. Four rats were used in a Non-Surgical condition group and another group was formed by nine rats that underwent various surgical procedures for the cranial sutures closure. The rats in the age between two and eight days underwent four experimental stages in operant conditioning boxes. In the first phase the bar press responses were modeled and, subsequently, 60 responses were reinforced under a scheme of continuous reinforcement (CRF) for three consecutive sessions. In the second phase, the scheme of CRF was replaced by schemes of fixed intervals (FI) with three values that were increased gradually (FI 4 s, FI 8 s FI s 11). In the third phase, the subjects underwent a multiple scheme with components FI 11 to Extinction (EXT) in the presence and absence of light, respectively. This discriminative training was continued until at least 80% of bar press response had occurred in the components of FI. Finally, in the fourth phase there was a reversal of the functions of the stimuli, so that the presence and absence of light started to follow, respectively, the FI and EXT components. The research result reveal that the procedures used in the constriction of the cerebral development did not produced evidences in the rats behavior under the reinforcement scheme, the discriminative learning and the reversion process

A intervenção no cérebro e a possível influência no responder dos organismos têm sido alvo de diversas pesquisas que visam analisar tal relação. Deste modo, o presente estudo busca fornecer indicadores dos possíveis efeitos do fechamento das suturas cranianas sobre a aprendizagem discriminativa em esquemas de reforçamento. Para isso, serviram como sujeitos quatro ratos cirurgicamente intactos e nove submetidos a diferentes procedimentos cirúrgicos para o fechamento das suturas cranianas. Os sujeitos, com idades entre dois e oito dias de vida, foram submetidos a quatro fases experimentais em caixas de condicionamento operante. Na primeira fase, respostas de pressão à barra foram modeladas e, na seqüência, 60 respostas foram reforçadas em esquema de reforçamento contínuo (CRF) por três sessões consecutivas. Na segunda fase, o esquema de CRF foi substituído por esquemas de intervalos fixos (FI) com três valores aumentados gradualmente (FI 4 s, FI 8 s e FI 11 s). Na terceira fase, os sujeitos foram submetidos a um esquema múltiplo composto pelos componentes FI 11 s e Extinção (EXT), na presença e ausência de luz, respectivamente. Este treino discriminativo foi mantido até que ao menos 80% das pressões à barra ocorressem nos componentes de FI. Finalmente, na quarta fase, houve uma reversão das funções dos estímulos, de modo que a presença e a ausência de luz passaram a acompanhar, respectivamente, os componentes de EXT e FI. De modo geral, os resultados revelaram que os procedimentos empregados na constrição do desenvolvimento cerebral não produziram efeitos evidentes no comportamento dos ratos sob esquema de reforçamento, assim como na aprendizagem discriminativa e sua reversão / The intervention in the brain and the possible influence on the response of organisms has been the subject of several studies designed to examine this correlation. The aim of the present study is to provide indicators of the possible effects of the cranial sutures closure to the discriminative learning in reinforcement procedures. Four rats were used in a Non-Surgical condition group and another group was formed by nine rats that underwent various surgical procedures for the cranial sutures closure. The rats in the age between two and eight days underwent four experimental stages in operant conditioning boxes. In the first phase the bar press responses were modeled and, subsequently, 60 responses were reinforced under a scheme of continuous reinforcement (CRF) for three consecutive sessions. In the second phase, the scheme of CRF was replaced by schemes of fixed intervals (FI) with three values that were increased gradually (FI 4 s, FI 8 s FI s 11). In the third phase, the subjects underwent a multiple scheme with components FI 11 to Extinction (EXT) in the presence and absence of light, respectively. This discriminative training was continued until at least 80% of bar press response had occurred in the components of FI. Finally, in the fourth phase there was a reversal of the functions of the stimuli, so that the presence and absence of light started to follow, respectively, the FI and EXT components. The research result reveal that the procedures used in the constriction of the cerebral development did not produced evidences in the rats behavior under the reinforcement scheme, the discriminative learning and the reversion process

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 100-108).

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Sidman's (2000) theory of stimulus equivalence states that all positive elements in a reinforcement contingency enter an equivalence class. The theory also states that if an element from an equivalence class conflicts with a programmed reinforcement contingency, the conflicting element will drop out of the equivalence class. Minster et al. (2006) found evidence suggesting that a conflicting element does not drop out of an equivalence class. In an effort to explain maintained accuracy on programmed reinforcement contingencies, the authors seem to suggest that participants will behave in accordance with a particular partitioning of the equivalence class which continues to include the conflicting element. This hypothesis seems to explain their data well, but their particular procedures are not a good test of the notion of "dropping out" due to the pre-establishment of equivalence classes before the conflicting member entered the class. The current experiment first developed unpartitioned equivalence classes and only later exposed participants to reinforcement contingencies that conflicted with pre-established equivalence classes. The results are consistent with the notion that a partition developed such that the conflicting element had dropped out of certain subclasses of the original equivalence class. The notion of a partitioning of an equivalence class seems to provide a fuller description of the phenomenon Sidman (1994, 2000) described as "dropping out" of an equivalence class.

This study hypothesized a direct relationship among three verbal phenomena: derived relational responding, verbal intelligence, and worry. It also hypothesized that experiential avoidance would mediate the relationship between derived relational responding and worry. Overall, results from this study failed to support a relationship between worry and the other two verbal phenomena, however, results did support a relationship between derived relational responding and verbal intelligence. Additionally, results indicated a significant relationship between experiential avoidance and worry. Future research should clarify the relationship among the three primary variables of interest, improve measurement of these variables, be more sensitive to external validity, and promote the study of acceptance-based treatments that target experiential avoidance.

Symmetry suppression was conducted for five subjects who demonstrated a tendency to derive equivalence relations based on conditional discrimination training in a match-to-sample procedure. Symmetry suppression was applied in three consecutive sessions in which symmetrical responses were suppressed for one stimulus class in the first condition, two stimulus classes in the second condition, and all three stimulus classes in the final condition. Symmetry suppression slowed the emergence of transitivity for two subjects and prevented it for the other three. Results indicated that unplanned features of stimulus configurations emerged as discriminative variables that controlled selection responses and altered the function of consequent stimuli. Disruption of cognitive development by conflicting contingencies in natural learning environments is discussed.

Training structures have been defined as the order and arrangement of baseline conditional discriminations within stimulus equivalence training. The three training structures most often used are, linear (trains A:B and B:C discrimination), many-to-one (trains B:A and C:A discriminations) , and one-to-many (trains A:B and A:C discriminations). Each training structure trains a different set of simultaneous and successive discriminations that are then needed in the test for derived relations (symmetry, reflexivity, transitivity, and symmetrical transitivity). The present experiment seeks to extend the research on stimulus equivalence training structures by using a within-subject design and adult human subjects. Three sets of 9 arbitrary stimuli were trained concurrently each with a different training structure. From the beginning, training and testing trials were intermixed. The likelihood of producing stimulus equivalence formation was equal across structures.

Attempts to control various aspects of response requirements and sample viewing durations of sample stimuli show that an increase in both facilitates acquisition of conditional discriminations. Despite these attempts, few empirical data exist that demonstrate the relative contributions of both response- and time-dependent schedules. In addition, viewing opportunities of sample stimuli are present outside of the researchers' control, allowing for 'unauthorized sample viewing.' This study employed a titrating delay matching-to-sample procedure to systematically control various aspects of response requirements and sample viewing durations to independently assess their relative contributions towards conditional discrimination performance. Four pigeons worked on a titrating delay matching-to-sample procedure in which the delay between sample offset and comparison onset continuously adjusted as a function of the accuracy of the pigeons' choices. Results show sample viewing durations contribute most toward conditional discrimination performance. The data show 'unauthorized sample viewing' improved acquisition of conditional discriminations and should be a consideration in design of future research.