Transfer of functions based on equivalence class formation using musical stimuli.

Empirical evidence has supported that musical excerpts written in major and minor modes are responsible for evoking happiness and sadness, respectively. In this study, we evaluated whether the emotional content evoked by musical stimuli would transfer to abstract figures when they became members of the same equivalence class. Participants assigned to the experimental group were submitted to a training procedure to form equivalence classes comprising musical excerpts (A) and meaningless abstract figures (B, C, and D). Afterward, transfer of function was evaluated using a semantic differential. Participants in the control group showed positive semantic differential scores for major mode musical excerpts, negative scores for minor mode musical excerpts, and neutral scores for the B, C, and D stimuli. Participants in the experimental groups showed positive semantic differential scores for visual stimuli equivalent to the major modes and negative semantic differential scores for visual stimuli equivalent to the minor modes. These results indicate transfer of function of emotional content present in musical stimuli through equivalence class formation. These findings could provide a more comprehensive understanding of the effects of using emotional stimuli in equivalence class formation experiments and in transfer of function itself.

Generalized contextual control based on nonarbitrary and arbitrary transfer of stimulus functions.

Two experiments with human adults investigated the extent to which the transfer of function in accordance with nonarbitrary versus arbitrary stimulus relations may be brought under contextual control. Experiment 1 comprised four phases. Phase 1 consisted of multiple-exemplar training to establish discriminative functions for solid, dashed, or dotted lines. Phase 2 trained and tested two equivalence classes, each containing a 3D picture, a solid, a dashed, and a dotted form. During Phase 3, a discriminative function was established for each 3D picture. Phase 4 presented the solid, dashed, and dotted stimuli in two different frames, black or gray. The black frame cued function transfer based on nonarbitrary stimulus relations (Frame Physical); the gray frame cued function transfer based on equivalence relations (Frame Arbitrary). Testing and training with the frames was continued until contextual control was established; subsequently contextual control was demonstrated with novel equivalence classes with stimuli composed of the same forms. Experiment 2 replicated and extended Experiment 1 by demonstrating that such contextual control generalized to novel equivalence classes comprising novel forms and responses. The potential implications of the findings for developing increasingly precise experimental analyses of clinically relevant phenomena are considered (e.g., defusion).

Functional equivalence classes in rats: Repeated olfactory discrimination reversals and delayed stimulus probes.

The simultaneous matching-to-sample procedures that are widely used to study stimulus equivalence in human participants have generally been unsuccessful in animals. However, functional equivalence classes have been demonstrated in pigeons and sea lions using a concurrent repeated reversal discrimination procedure. In this procedure, responding to one set of stimuli is reinforced but responding to a different set is not and the set associated with reinforcement is changed with multiple reversals during the experiment. The experiments reported here were designed to assess whether functional equivalence classes could be demonstrated in rats using similar techniques. Rats were initially trained with two sets of olfactory stimuli (six odors/set). Following many reversals, probe reversal sessions were conducted in which rats were exposed to a subset of the members of each set and, later in the session, the withheld stimuli were introduced. Responding to these delayed probe trials in accord with the reversed contingencies constituted transfer of function. There was some evidence of transfer in Experiment 1, but the effects were relatively weak and variable. Experiment 2 introduced procedural changes and found strong evidence of transfer of function consistent with the formation of functional equivalence classes. These procedures offer a promising strategy to study symbolic behavior in rodents.

Establishing derived reinforcers via stimulus equivalence.

If one of several stimuli in an equivalence class acquires a function, it transfers to all members of the respective class. Even though research has demonstrated this transfer across a variety of stimulus functions (e.g., discriminative), few studies have focused on the transfer of the reinforcing function. The current study extended previous literature by establishing derived reinforcers using conditional discrimination training with six neurotypical adults. We established three 4-member equivalence classes and then created a discriminative stimulus in one member by correlating it with reinforcement. We also expanded classes by adding a stimulus to each class and testing its function. During the transfer of function tests, five out of six participants chose the derived reinforcers more than the other stimuli. Three participants required remedial training or testing prior to demonstrating transfer of function. Results show that stimulus equivalence training is an effective and efficient paradigm to establish derived reinforcers.

Repeated reversals of concurrent olfactory discriminations in rats: A search for functional equivalence.

Equivalence class formation has been difficult to demonstrate in nonhumans, but one method that has been successful is a simple discrimination procedure in which contingencies associated with two sets of arbitrary discriminative stimuli are repeatedly reversed. Pigeons and sea lions shift responding after encountering the newly-reversed contingency with only a few set members, showing evidence of functional equivalence. We used this strategy to determine whether similar findings would occur in rats using olfactory stimuli. Rats were trained to nose-poke in the presence of six stimuli arbitrarily designated as members of the positive set; responses to the six members of the negative set were not reinforced. When discriminative performance was established, contingencies associated with each set were reversed and re-reversed each time subjects met a performance criterion. All subjects successfully acquired the concurrent simple discriminations and were exposed to between 12 and 60 reversals, but none showed clear evidence of functional class formation until a final procedure in which the stimulus sets that had been in place were arbitrarily rearranged. Acquisition with these new stimulus sets was impaired, showing that class membership generated by the original stimulus sets interfered with learning the new ones, thus providing evidence of functional equivalence.

Formation of Equivalence Classes Including Emotional Functions

Eleven participants in two experimental groups, DMTS-3s and DMTS-6s, trained conditional discriminations (AB, AC, CD, DE, and EF) with the potential emergence of three 6-member equivalence classes. The A stimuli (A1, A2, and A3) consisted of faces showing angry, neutral, and happy facial expressions, respectively. All participants responded in accordance with the experimentally defined criterion of 95% correct on two consecutive transitivity BF and equivalence FB test blocks. Next, participants rated the abstract D1 and D3 stimuli equivalent to the angry and happy faces (A1 and A3) on a Semantic Differential Rating Scale. A control group rated the facial stimuli and the abstract D stimuli on a similar rating scale. Results show that stimuli are more related when trained with DMTS3s than DMTS-6s. Abstract D3 stimuli rated by the DMTS-3s group deviated less from control group ratings of respective faces than ratings of all other abstract D stimuli by the two experimental groups (AU)

Equivalence relations and the contextual control of multiple derived stimulus functions.

Contextual control is a key aspect in equivalence research to support the claim that stimuli may have multiple functions or symbols may have multiple meanings. The present study investigated the contextual control of multiple derived stimulus functions in two experiments. In Experiment 1, equivalence classes were formed and one stimulus set from each class was used to establish two different functions: one via positive reinforcement (key-pressing) and another via negative reinforcement (button clicking), both under contextual control of two different background colors. Later, other stimuli from the equivalence class were presented on those background colors and contextual control of multiple derived stimulus functions was assessed. Experiment 2 added a third background in which no programmed response was reinforced, that is, responses were extinguished. Transfer-of-function tests revealed contextual control of three different functions, including derived extinction. Implications for equivalence relations as a behavior-analytical model of symbolic functioning are discussed.

Investigating the Impact of Stimulus Equivalence on Children's Food Choice and Preference / Investigando o Impacto da Equivalência de Estímulos na Escolha e Preferência de Alimentos por Crianças / Investigando el Impacto de la Equivalencia de Estímulos en la Elección y Preferencia de Alimentos por Niños

Abstract This study investigated the influence of character on food's choices. Eleven preschool children were trained to form two equivalent stimulus classes, each comprising one a cartoon character, a geometric shape, and an abstract symbol. One class had a liked character and the other a disliked character. Three preference tests were conducted where the children had to choose between two identical packages with samples of the same snack, differing only by the label. In Test 1 the labels were symbols of the same class as the liked and disliked characters; in Test 2 the choice was between the symbol of the same class as the disliked character and a new symbol; and in Test 3 children chose between the symbol of the equivalence class with the liked character and the logo of a known brand. Most children chose first, and reported to like more, the snack labeled with the symbol of the same class as the liked character. They also chose, and reported to like more, the snack labeled with a new stimulus over the symbol of the same class as the disliked character. These results confirmed that stimulus equivalence is a useful paradigm to investigate formation of preference for brands.

Resumo Esta pesquisa investigou a influência de personagens em escolhas alimentares. Doze crianças pré-escolares formaram inicialmente duas classes de estímulos equivalentes, cada uma contendo um personagem, uma forma geométrica e um símbolo abstrato. Uma das classes continha um personagem de que a criança gostava e a outra de que a criança não gostava. Três testes de escolha alimentar foram conduzidos nos quais o participante deveria escolher entre duas embalagens idênticas com o mesmo alimento, diferindo somente o rótulo. No Teste 1, os rótulos continham os símbolos da classe do personagem atrativo e não atrativo; No Teste 2, a escolha era entre o símbolo da classe do personagem não atrativo e um símbolo novo; e no Teste 3 a escolha era entre o símbolo da classe do personagem atrativo e o logo de uma marca conhecida. A maioria das crianças escolheu e demonstrou preferência pelo alimento com o símbolo equivalente ao personagem de que gostava. Também escolheram e disseram gostar mais do alimento com o símbolo novo no rótulo ao invés do que continha o símbolo equivalente ao personagem não atrativo. Os resultados apontam a equivalência de estímulos como uma abordagem útil para investigar a formação de preferência por marcas.

Resumen Este estudio investigó la influencia de los personajes en la elección de alimentos. 12 niños preescolares formaran dos clases de estímulos equivalentes, contiendo a un personaje infantil, una forma geométrica, y a un símbolo abstracto. Una clase tenía un personaje que le gustaba al niño y la otra un personaje que no le gustaba. Tres testes de preferencia fueron conducidos, en los que los niños tenían que escoger entre dos pedazos de la misma galleta, diferenciándose sólo por la etiqueta en el recipiente. En el Test 1, las etiquetas eran símbolos equivalentes al personaje que favorito y al que no le gustaba; en el Test 2, la elección fue entre el símbolo equivalente al personaje que no le gustaba y un símbolo nuevo; y en el Test 3, nos niños escogían entre el símbolo equivalente al personaje favorito y el logotipo de una marca conocida. La mayoría de los niños escogió primero, y prefirieron, la galleta etiquetada con el símbolo equivalente al personaje favorito. También escogieron, y prefirieron, la galleta etiquetada con el estímulo nuevo que con el símbolo equivalente al personaje que no les gustaba. Estos resultados confirmaron que la equivalencia de estímulos es un paradigma útil para investigar la formación de preferencia por las marcas.

Narrative: Why It's Important, and How It Works.

Behavior analysts have said little about narrative and storytelling, emphasizing instead the functional/pragmatic aspects of verbal behavior. Nevertheless, these are ubiquitous human activities, and they are important to understand. Stories are prominent in essays on social issues, fund-raising appeals and political speeches, and they are the bedrock of theater. Foundational narratives are at the roots of major religions and of conflicts between them, and narrative has been proposed as an organizing basis for psychological wellbeing as well as a source of empathetic reactions. The ongoing process of reading or hearing a good story entails interlocking relations between establishing stimuli and their related, differentiated reinforcing consequences, with a story's coherence providing a key to its reinforcing effects. What are the behavioral principles that underlie the repertoires involved in all this? Behavior analysts have defined and studied some-the basic verbal classes, of course, although temporally extended sequences require some adjustments in these. Intraverbal behavior needs to be parsed into sub-categories to delineate highly varied sequences such as occur in paraphrase and translation. These two, along with imitation, generalized imitation and re-telling of stories, entail a salient role of complex invariance. The terms pliance and tracking help to balance the roles of speaker and listener, and to account for joint attention, which appears important in early verbal development. Transfer and transformation of function are additional ubiquitous processes, addressed through stimulus equivalence, relational frames, and other higher-order operants, especially naming, which entails the fusion of speaking and listening. Finally, we should consider ways in which a behavioral understanding of narrative can serve both behavior analysis and its surrounding culture.

The transfer of Crel contextual control (same, opposite, less than, more than) through equivalence relations.

According to Relational Frame Theory (RFT) Crel denotes a contextual stimulus that controls a particular type of relational response (sameness, opposition, comparative, temporal, hierarchical etc.) in a given situation. Previous studies suggest that contextual functions may be indirectly acquired via transfer of function. The present study investigated the transfer of Crel contextual control through equivalence relations. Experiment 1 evaluated the transfer of Crel contextual functions for relational responses based on sameness and opposition. Experiment 2 extended these findings by evaluating transfer of function using comparative Crel stimuli. Both experiments followed a similar sequence of phases. First, abstract forms were established as Crel stimuli via multiple exemplar training (Phase 1). The contextual cues were then applied to establish arbitrary relations among nonsense words and to test derived relations (Phase 2). After that, equivalence relations involving the original Crel stimuli and other abstract forms were trained and tested (Phase 3). Transfer of function was evaluated by replacing the directly established Crel stimuli with their equivalent stimuli in the former experimental tasks (Phases 1 and 2). Results from both experiments suggest that Crel contextual control may be extended via equivalence relations, allowing other arbitrarily related stimuli to indirectly acquire Crel functions and regulate behavior by evoking appropriate relational responses in the presence of both previously known and novel stimuli.

Transfer of function and prior derived-relations testing.

This experiment assessed transfer of function through equivalence relations with and without prior derived-stimulus-relations (DSR) testing. In a DSR-Testing Group, eight college students learned A-B and A-C discriminations in baseline. They then derived the B-C and C-B equivalence relations before being exposed to a transfer-of-function manipulation and test. Eight participants in a No-DSR Testing Group were exposed to the transfer-of-function manipulation and test immediately after learning the baseline discriminations (i.e., B-C and C-B testing were omitted). In the transfer-of-function manipulation, participants learned to respond differently in the presence of B1 and B2 to avoid money loss. In the transfer-of-function test, responding in the presence of C1 and C2 was measured in the absence of differential consequences. Transfer of function occurred reliably only in the DSR-Testing Group (i.e., participants responding to C1 and C2 in the manner they learned to respond to B1 and B2, respectively). These findings support the notion that prior DSR testing can be critical to observing transfer of function.

Effects of select and reject control on equivalence class formation and transfer of function.

The present study used a single-subject design to evaluate the effects of select or reject control on equivalence class formation and transfer of function. Adults were exposed to a matching-to-sample task with observing requirements (MTS-OR) in order to bias the establishment of sample/S+ (select) or sample/S- (reject) relations. In Experiment 1, four sets of baseline conditional relations were taught-two under reject control (A1B2C1, A2B1C2) and two under select control (D1E1F1, D2E2F2). Participants were tested for transitivity, symmetry, equivalence and reflexivity. They also learned a simple discrimination involving one of the stimuli from the equivalence classes and were tested for the transfer of the discriminative function. In general, participants performed with high accuracy on all equivalence-related probes as well as the transfer of function probes under select control. Under reject control, participants had high scores only on the symmetry test; transfer of function was attributed to stimuli programmed as S-. In Experiment 2, the equivalence class under reject control was expanded to four members (A1B2C1D2; A2B1C2D1). Participants had high scores only on symmetry and on transitivity and equivalence tests involving two nodes. Transfer of function was extended to the programmed S- added to each class. Results from both experiments suggest that select and reject controls might differently affect the formation of equivalence classes and the transfer of stimulus functions.

Equivalência de estímulos e ciúme: efeito de história pré-experimental / Stimulus equivalence and jealousy: effect of pre-experimental history

A formação de classes de estímulos equivalentes tem sido usada como modelo experimental para investigar uma série de fenômenos comportamentais, tais como o desenvolvimento de comportamento simbólico e a transferência de funções que os eventos ambientais adquirem por meio de relações condicionais. O objetivo deste estudo consistiu em analisar o efeito de estímulos com alto grau afetivo pré-experimentalmente constituído, na formação de classes de equivalência estabelecidas em contexto experimental, quando as relações emergentes podem se caracterizar por um conflito na escolha dos estímulos. Participaram 17 estudantes universitários que foram submetidos ao procedimento de escolha de acordo com modelo e aos testes das relações emergentes, para formar quatro classes de equivalência com quatro estímulos cada. Verificou-se que 10 dos 17 participantes formaram as classes equivalentes e observou-se correlação positiva entre o desempenho no Teste de Equivalência e o escore na Escala de Ciúme Romântico, sugerindo que a história pré-experimental referente ao envolvimento afetivo interferiu no desempenho dos participantes. O efeito de interferência provavelmente é devido ao conflito entre contingências: uma que controla o responder diante de relações condicionais pré-experimentalmente estabelecidas, envolvendo estímulos com alto valor afetivo, e outra estabelecida no contexto experimental.

The formation of stimulus equivalence classes has been used as an experimental model to investigate a series of behavioral phenomena, such as the development of symbolic behavior and transfer of functions that environmental events acquire through conditional relations. The aim of this study was to analyze the effect of stimuli with high pre-experimentally constituted affective grade in the formation of equivalence classes established in an experimental context, when the emergent relations can be characterized by a conflict in choosing stimuli. Participants were 17 college students exposed to matching to sample procedure and the tests of emergent relations to form four equivalence classes with four stimuli each. The results showed that 10 out of 17 participants formed equivalence classes, and positive correlation was observed between the performance on the Equivalence Test and the score on the Romantic Jealousy Scale, suggesting that the pre-experimental history related to emotional involvement interfered with participants' performance. The interference effect is probably due to the conflict between contingencies: one that controls responses to pre-experimentally established conditional relations involving stimuli with high emotional value, and another one, established in the experimental setting.

Transferencia de funciones sintácticas artificiales entre estímulos relacionados por equivalencia: Un estudio de potenciales cerebrales relacionados con eventos / Transfer of artificial syntax functions among equivalence - related stimuli: An event - related brain potentials study

La formación de clases de equivalencia entre estímulos ha sido propuesta en el campo del Análisis Experimental del Comportamiento como un prerrequisito conductual para el lenguaje. Adicionalmente, existe evidencia de que la transferencia de función entre estímulos equivalentes podría explicar la adquisición de estructuras sintácticas simples. No obstante, la simplicidad de las funciones sintácticas estudiadas no capturó la complejidad combinatoria de la gramática natural. Si la transferencia de funciones en clases de equivalencia es un modelo posible del desarrollo de estructuras gramaticales, debería ser verificado en contextos más válidos para el estudio del lenguaje. Los objetivos del trabajo realizado fueron los siguientes: (1) analizar la transferencia de funciones sintácticas en clases de equivalencia en un contexto válido para el estudio de la adquisición de reglas gramaticales, utilizando para ello el paradigma de gramáticas artificiales y (2) analizar los potenciales cerebrales relacionados con el procesamiento de esta transferencia de función, en secuencias gramaticales y no gramaticales. Se encontró evidencia comportamental de transferencia de función en un subgrupo de los sujetos experimentales. El potencial P600, típicamente asociado al costo de integración sintáctica en contextos lingüísticos, fue observado en estos sujetos ante: violaciones gramaticales con estímulos originales de la gramática artificial y secuencias con estímulos relacionados por equivalencia (gramaticales y no gramaticales). Se interpretó que el procesamiento de las secuencias artificiales implicó mecanismos neurobiológicos similares a los asociados a la sintaxis del lenguaje y que el patrón de actividad P600 observado puede ser explicado por el aumento del costo de integración de los estímulos al contexto previo.

Stimulus equivalence class formation has been proposed as a behavioral prerequisite for language within the field of experimental analysis of behavior. Additionally, there is evidence that transfer of function among equivalent stimuli may explain acquisition of simple syntactic structures. However these experiments analyzed sequence functions that did not capture the complexity and versatility of natural grammar. If transfer of function between stimuli that belong to the same equivalence classes is indeed a useful model for the development of grammatical structures, then we should be able to verify it in a more valid context for the study of language. Artificial grammar learning tasks have been applied to the study of several aspects of language acquisition, from word segmentation to phrase structure and syntax rules. Furthermore, it has been shown that patterns of brain activity during processing of artificial grammars resemble those observed in language syntax processing. In particular, structural violations of language sentences and artificial grammar sequences both activate Broca's area. Therefore, artificial grammars provide a valid paradigm to study the learning of syntactic functions. The main objectives of the current work were: (1) to analyze transfer of function within equivalence classes in a valid context for the study of syntax acquisition, applying the artificial grammar paradigm and (2) to analyze brain potentials related to the transfer of function in grammatical and ungrammatical sequences. Fifteen subjects were trained to form two three-stimulus equivalence classes and then performed an artificial grammar learning task. One stimulus from each equivalence class was included as an item in the artificial grammar categories. During a test stage, subjects were asked to classify new artificial grammar sequences as grammatical or ungrammatical, while their EEG activity was registered. Half of these new sequences were built using the original training items and the other half contained equivalence-related stimulus. Subjects were assigned to two groups according to their performance in this test stage. Those participants whose percentage of correct responses was above 50 % were considered to pass, while those below were assigned to the fail group. We found behavioral evidence of transfer of function in the pass subgroup. These participants were able to correctly discriminate grammatical from un grammatical sequences that were built using original or equivalence-related stimulus. Event-Related potential Analysis of the EEG signal indicated a posteriorly distributed positivity with a topography and time-course similar to the P600 potential. Within linguistic contexts, P600 is interpreted as the neural correlate of prediction and integration costs during syntax processing. It has been proposed that sentence comprehension depends on predictive mechanisms that combine lexical, semantic and syntactic information from linguistic input to anticipate future words. Processing of incoming stimuli is facilitated by pre- activation, allowing rapid integration to previous context. However, when the input does not match predictions, this integration becomes slower and more difficult, requiring additional neural resources. The P600 has been considered and index of increased integration costs, generated by unfulfilled predictions of word category and morphology based on previous context. In the present experiment, the P600 was observed after: grammar violations with the original artificial grammar lexicon and artificial sequences containing equivalence-related stimulus (both grammatical and ungrammatical). Results showed that artificial grammar processing involved neurobiological mechanisms that are similar to those associated in natural grammar processing. We interpreted the observed P600 pattern in terms of an increased stimulus integration cost, both in the case of grammatical and ungrammatical equivalence-related stimulus. Even though we consider that transference of function and equivalence class formations are by themselves insufficient to explain the complexity of natural grammar, we propose that this processes might be relevant to its acquisition and evolution, constituting a behavioral prerequisite for language development.

Transferencia de funciones sintácticas artificiales entre estímulos relacionados por equivalencia: Un estudio de potenciales cerebrales relacionados con eventos / Transfer of artificial syntax functions among equivalence - related stimuli: An event - related brain potentials study

La formación de clases de equivalencia entre estímulos ha sido propuesta en el campo del Análisis Experimental del Comportamiento como un prerrequisito conductual para el lenguaje. Adicionalmente, existe evidencia de que la transferencia de función entre estímulos equivalentes podría explicar la adquisición de estructuras sintácticas simples. No obstante, la simplicidad de las funciones sintácticas estudiadas no capturó la complejidad combinatoria de la gramática natural. Si la transferencia de funciones en clases de equivalencia es un modelo posible del desarrollo de estructuras gramaticales, debería ser verificado en contextos más válidos para el estudio del lenguaje. Los objetivos del trabajo realizado fueron los siguientes: (1) analizar la transferencia de funciones sintácticas en clases de equivalencia en un contexto válido para el estudio de la adquisición de reglas gramaticales, utilizando para ello el paradigma de gramáticas artificiales y (2) analizar los potenciales cerebrales relacionados con el procesamiento de esta transferencia de función, en secuencias gramaticales y no gramaticales. Se encontró evidencia comportamental de transferencia de función en un subgrupo de los sujetos experimentales. El potencial P600, típicamente asociado al costo de integración sintáctica en contextos ling³ísticos, fue observado en estos sujetos ante: violaciones gramaticales con estímulos originales de la gramática artificial y secuencias con estímulos relacionados por equivalencia (gramaticales y no gramaticales). Se interpretó que el procesamiento de las secuencias artificiales implicó mecanismos neurobiológicos similares a los asociados a la sintaxis del lenguaje y que el patrón de actividad P600 observado puede ser explicado por el aumento del costo de integración de los estímulos al contexto previo.(AU)

Stimulus equivalence class formation has been proposed as a behavioral prerequisite for language within the field of experimental analysis of behavior. Additionally, there is evidence that transfer of function among equivalent stimuli may explain acquisition of simple syntactic structures. However these experiments analyzed sequence functions that did not capture the complexity and versatility of natural grammar. If transfer of function between stimuli that belong to the same equivalence classes is indeed a useful model for the development of grammatical structures, then we should be able to verify it in a more valid context for the study of language. Artificial grammar learning tasks have been applied to the study of several aspects of language acquisition, from word segmentation to phrase structure and syntax rules. Furthermore, it has been shown that patterns of brain activity during processing of artificial grammars resemble those observed in language syntax processing. In particular, structural violations of language sentences and artificial grammar sequences both activate Brocas area. Therefore, artificial grammars provide a valid paradigm to study the learning of syntactic functions. The main objectives of the current work were: (1) to analyze transfer of function within equivalence classes in a valid context for the study of syntax acquisition, applying the artificial grammar paradigm and (2) to analyze brain potentials related to the transfer of function in grammatical and ungrammatical sequences. Fifteen subjects were trained to form two three-stimulus equivalence classes and then performed an artificial grammar learning task. One stimulus from each equivalence class was included as an item in the artificial grammar categories. During a test stage, subjects were asked to classify new artificial grammar sequences as grammatical or ungrammatical, while their EEG activity was registered. Half of these new sequences were built using the original training items and the other half contained equivalence-related stimulus. Subjects were assigned to two groups according to their performance in this test stage. Those participants whose percentage of correct responses was above 50 % were considered to pass, while those below were assigned to the fail group. We found behavioral evidence of transfer of function in the pass subgroup. These participants were able to correctly discriminate grammatical from un grammatical sequences that were built using original or equivalence-related stimulus. Event-Related potential Analysis of the EEG signal indicated a posteriorly distributed positivity with a topography and time-course similar to the P600 potential. Within linguistic contexts, P600 is interpreted as the neural correlate of prediction and integration costs during syntax processing. It has been proposed that sentence comprehension depends on predictive mechanisms that combine lexical, semantic and syntactic information from linguistic input to anticipate future words. Processing of incoming stimuli is facilitated by pre- activation, allowing rapid integration to previous context. However, when the input does not match predictions, this integration becomes slower and more difficult, requiring additional neural resources. The P600 has been considered and index of increased integration costs, generated by unfulfilled predictions of word category and morphology based on previous context. In the present experiment, the P600 was observed after: grammar violations with the original artificial grammar lexicon and artificial sequences containing equivalence-related stimulus (both grammatical and ungrammatical). Results showed that artificial grammar processing involved neurobiological mechanisms that are similar to those associated in natural grammar processing. We interpreted the observed P600 pattern in terms of an increased stimulus integration cost, both in the case of grammatical and ungrammatical equivalence-related stimulus. Even though we consider that transference of function and equivalence class formations are by themselves insufficient to explain the complexity of natural grammar, we propose that this processes might be relevant to its acquisition and evolution, constituting a behavioral prerequisite for language development.(AU)

The transfer of Cfunc contextual control through equivalence relations.

Derived relational responding is affected by contextual stimuli (Cfunc) that select specific stimulus functions. The present study investigated the transfer of Cfunc contextual control through equivalence relations by evaluating both (a) the maintenance of Cfunc contextual control after the expansion of a relational network, and (b) the establishment of novel contextual stimuli by the transfer of Cfunc contextual control through equivalence relations. Initially, equivalence relations were established and contingencies were arranged so that colors functioned as Cfunc stimuli controlling participants' key-pressing responses in the presence of any stimulus from a three-member equivalence network. To investigate the first research question, the three-member equivalence relations were expanded to five members and the novel members were presented with the Cfunc stimuli in the key-pressing task. To address the second goal of this study, the colors (Cfunc) were established as equivalent to certain line patterns. The transfer of contextual cue function (Cfunc) was tested replacing the colored backgrounds with line patterns in the key-pressing task. Results suggest that the Cfunc contextual control was transferred to novel stimuli that were added to the relational network. In addition, the line patterns indirectly acquired the contextual cue function (Cfunc) initially established for the colored backgrounds. The conceptual and applied implications of Cfunc contextual control are discussed.

Computerized assessment of food preferences in adolescents in the stimulus equivalence paradigm / Avaliação computadorizada das preferências alimentares em adolescentes no paradigma de equivalência de estímulos / Evaluación computarizada de las preferencias alimentarias de los adolescentes en lo paradigma de la equivalencia de estímulo

In Experiment 1, 71 participants were trained to match three pictures of facial expressions (one that expressed happiness and two that expressed emotional neutrality) to three abstract line drawings and match three healthy food names to the abstract line drawings. The participants were then tested to verify equivalence between facial expressions, abstract pictures, and foods. They were required to rate the foods for pleasantness at the beginning and end of the experiment. The experiment had three different experimental groups that differed only in the amount of training. The foods that were equivalent to the happy and neutral female faces received more positive evaluations than the foods that were equivalent to the neutral male face; however, the data presented high variability. In Experiment 2, schematic faces and fictitious food names were used in a delayed matching-to-sample procedure. The food that was equivalent to the happy face was evaluated as more pleasant, and the food that was equivalent to the sad face was evaluated as less pleasant.(AU).

No Experimento 1 foram ensinadas relações entre três expressões faciais (uma de alegria e duas neutras) a três desenhos abstratos e em seguida ensinado a relação de três nomes de alimentos saudáveis aos três desenhos abstratos para 71 participantes. Depois de passar pelo treino das relações, os participantes foram, então, testados para verificar a equivalência entre as expressões faciais, as imagens abstratas e os alimentos. A avaliação da preferência alimentar foi realizada no início e no final do experimento. O experimento teve três diferentes grupos experimentais que diferiam apenas na quantidade de treinamento das relações. Os alimentos equivalentes às expressões faciais de alegria e neutra feminina tiveram avaliações mais positivas do que os alimentos equivalentes à face neutra masculina, no entanto, os dados apresentaram grande variabilidade. No Experimento 2 expressões faciais esquemáticas e nomes fictícios de alimentos foram usados em um procedimento de emparelhamento com o modelo com atraso. O alimento treinado com a face feliz foi avaliado como mais agradável e o relacionado a uma face triste foi avaliado como menos agradável.(AU).

En el experimento 1 se enseñaban las relaciones entre los tres expresiones faciales (una de alegría y neutral dos) para tres diseños abstractos y luego enseñó la relación de los tres nombres de los alimentos saludables en tres diseños abstractos a 71 participantes. Después de pasar por la formación de las relaciones, los participantes fueron analizadas para la equivalencia entre las expresiones faciales, las imágenes abstractas y alimentos. La evaluación de la preferencia de alimentos se realizó al inicio y al final del experimento. El experimento consistió en tres diferentes grupos experimentales que diferían sólo en la cantidad de entrenamiento. Los alimentos equivalentes a las expresiones faciales de alegría y mujeres neutral sido objeto de evaluaciones más positivas que los alimentos equivalente a cara neutro masculino, sin embargo, los datos muestran una gran variabilidad. En el Experimento 2 expresiones faciales esquemáticos y nombres fictícios de alimentos fueron utilizados en un procedimiento de igualación a la muestra con retraso. La alimentación equivalente a la cara feliz se evaluó como más agradable y el equivalente a la cara triste se evaluó como menos agradable.(AU).

Computerized assessment of food preferences in adolescents in the stimulus equivalence paradigm / Avaliação computadorizada das preferências alimentares em adolescentes no paradigma de equivalência de estímulos / Evaluación computarizada de las preferencias alimentarias de los adolescentes en lo paradigma de la equivalencia de estímulo

In Experiment 1, 71 participants were trained to match three pictures of facial expressions (one that expressed happiness and two that expressed emotional neutrality) to three abstract line drawings and match three healthy food names to the abstract line drawings. The participants were then tested to verify equivalence between facial expressions, abstract pictures, and foods. They were required to rate the foods for pleasantness at the beginning and end of the experiment. The experiment had three different experimental groups that differed only in the amount of training. The foods that were equivalent to the happy and neutral female faces received more positive evaluations than the foods that were equivalent to the neutral male face; however, the data presented high variability. In Experiment 2, schematic faces and fictitious food names were used in a delayed matching-to-sample procedure. The food that was equivalent to the happy face was evaluated as more pleasant, and the food that was equivalent to the sad face was evaluated as less pleasant.

No Experimento 1 foram ensinadas relações entre três expressões faciais (uma de alegria e duas neutras) a três desenhos abstratos e em seguida ensinado a relação de três nomes de alimentos saudáveis aos três desenhos abstratos para 71 participantes. Depois de passar pelo treino das relações, os participantes foram, então, testados para verificar a equivalência entre as expressões faciais, as imagens abstratas e os alimentos. A avaliação da preferência alimentar foi realizada no início e no final do experimento. O experimento teve três diferentes grupos experimentais que diferiam apenas na quantidade de treinamento das relações. Os alimentos equivalentes às expressões faciais de alegria e neutra feminina tiveram avaliações mais positivas do que os alimentos equivalentes à face neutra masculina, no entanto, os dados apresentaram grande variabilidade. No Experimento 2 expressões faciais esquemáticas e nomes fictícios de alimentos foram usados em um procedimento de emparelhamento com o modelo com atraso. O alimento treinado com a face feliz foi avaliado como mais agradável e o relacionado a uma face triste foi avaliado como menos agradável.

En el experimento 1 se enseñaban las relaciones entre los tres expresiones faciales (una de alegría y neutral dos) para tres diseños abstractos y luego enseñó la relación de los tres nombres de los alimentos saludables en tres diseños abstractos a 71 participantes. Después de pasar por la formación de las relaciones, los participantes fueron analizadas para la equivalencia entre las expresiones faciales, las imágenes abstractas y alimentos. La evaluación de la preferencia de alimentos se realizó al inicio y al final del experimento. El experimento consistió en tres diferentes grupos experimentales que diferían sólo en la cantidad de entrenamiento. Los alimentos equivalentes a las expresiones faciales de alegría y mujeres neutral sido objeto de evaluaciones más positivas que los alimentos equivalente a cara neutro masculino, sin embargo, los datos muestran una gran variabilidad. En el Experimento 2 expresiones faciales esquemáticos y nombres fictícios de alimentos fueron utilizados en un procedimiento de igualación a la muestra con retraso. La alimentación equivalente a la cara feliz se evaluó como más agradable y el equivalente a la cara triste se evaluó como menos agradable.

Equivalência de estímulos e transferência de função: avaliando os efeitos dos controles por seleção e por rejeição / Stimulus equivalence and transfer of function: evaluating the effects of select and reject controls

Em uma tarefa de emparelhamento com o modelo envolvendo duas escolhas, o participante pode aprender tanto a selecionar o estímulo correto (controle por seleção) quanto a rejeitar o estímulo incorreto (controle por rejeição). O presente trabalho investigou o efeito dos controles por seleção e por rejeição sobre a formação de classes de estímulos equivalentes e sobre a transferência de função discriminativa. O Capítulo 1 apresenta uma revisão metodológica que sistematizou os procedimentos utilizados para inferir a ocorrência desses controles, bem como os procedimentos utilizados para manipulá-los experimentalmente. O Capítulo 2 apresenta um experimento que investigou o efeito da manipulação da observação dos estímulos de comparação sobre o estabelecimento dos controles por seleção e por rejeição. Participantes adultos foram submetidos a um treino de discriminações condicionais por meio do procedimento de emparelhamento com o modelo com observação requerida (MTS-OR). Os resultados sugerem que a ocorrência do controle por seleção foi mais provável para os participantes que foram exigidos observar o S+ ao longo de todas as tentativas de treino; o controle por rejeição só ocorreu para os participantes que foram exigidos observar o S-. Nesse último caso, impedir os participantes de observar o S+ favoreceu o estabelecimento do controle pelo S-. Por fim, o Capítulo 3 apresenta um conjunto de experimentos que avaliou o efeito dos controles por seleção e por rejeição sobre os testes de formação de classe de equivalência e sobre a transferência de função discriminativa. O procedimento de MTS-OR, aliado ao uso de diferentes proporções de S+/S-, permitiu a manipulação experimental dos controles investigados. A transferencia de função foi avaliada por meio de uma tarefa discriminativa simples sucessiva envolvendo respostas ao teclado.(AU)

In a two-choice matching-to-sample task, the participant might learn either to select the correct stimulus (select control) or to reject the incorrect one (reject control). The present dissertation investigated the effects of select and reject controls upon equivalence-class formation and transfer of discriminative function. Chapter 1 presents a methodological review that analyzed procedures used to infer the occurrence of such controls and also procedures used to experimentally manipulate them. Chapter 2 presents an experiment that evaluated the effects of manipulating observing responses towards comparison stimuli upon the establishment of select or reject controls. Adults participated and were exposed to a conditional discrimination training in a matching-tosample task with observing requirements (MTS-OR). Results suggest that select control was more likely to occur for participants that were required to observe the S+ in every training trial; reject control occurred only for participants that were required to observe the S- in every training trial. In this last case, preventing participants from observing the S+ also increased the chances of control by the S-. Finally, Chapter 3 presents experiments that evaluated the effects of select or reject controls upon equivalence-class-formation tests and transfer of discriminative function. The MTS-OR procedure, allied with different proportions of S+/S-, allowed manipulating the controls that were investigated. The transfer of function was evaluated by means of a simple successive discrimination task involving key-pressing responses on the keyboard.(AU)