Marcelo Vitor Silveira

We examined equivalence‐based N400 effects by comparing EEG data from participants with different experiences with equivalence testing. Before a priming task used in EEG measurement, Group 1 was given only matching‐to‐sample training trials whereas Group 2 was exposed to matching‐to‐sample training and equivalence probe trials. We asked whether exposure to the reinforcement contingency was sufficient to bring about an N400 outcome that might indicate potentially emergent equivalence relations or if such a response depended on experience with equivalence tests. Results showed robust N400 in both groups. Experience with equivalence tests did not further increase the N400 effects. Our findings add confirmatory evidence that equivalence relations may originate via the reinforcement contingency alone. Furthermore, complementary EEG data collected from priming tasks involving words from natural language showed functional overlap between laboratory‐defined equivalence and natural word‐based N400 effects.

No Experimento 1, seis participantes foram treinados em um procedimento MTS de identidade (IDMTS) para estabelecer relações estímulo-estímulo A1A1, A2A2, A3A3; B1B1, B2B2, B3B3; e C1C1, C2C2, C3C3. Respostas corretas resultavam na apresentação de consequências específicas, Sr1, Sr2 e Sr3. Uma resposta de consumação às consequências específicas foi requerida para que os participantes pudessem coletar os pontos nas tentativas de treino. O procedimento MTS arbitrário foi utilizado para documentar a formação de três classes de equivalência A1B1C1Sr1, A2B2C2Sr2 e A3B3C3Sr3. Em uma fase subsequente, o IDMTS com consequências específicas foi empregado para treinar as relações D1D1, D2D2 e D3D3. Os estímulos D eram fotografias de faces humanas expressando alegria (D1), tristeza (D2) e neutralidade (D3). Por último, avaliações por meio do diferencial semântico atestaram a ocorrência da transferência das funções (i.e., “significados”) dos estímulos D para os estímulos C e para Sr1 e Sr3. Estes resultados sugeriram que as classes ABCSr se expandiram para incluir os estímulos significativos D (i.e., A1B1C1D1Sr1, A2B2C2D2Sr2 e A3B3C3D3Sr3). No Experimento 2 verificou-se que, para cinco participantes, o procedimento de reversão das consequências específicas Sr1 e Sr2 em relação aos estímulos C1, C2 e D1 e D2 deu origem a duas classes de equivalência reorganizadas (A1B1C2D2Sr2 e A2B2C1D1Sr1). Paralelamente, os dados do diferencial semântico documentaram a reversão dos significados atribuídos previamente aos estímulos D1 e D2. Estes achados sugerem que o procedimento de reversão reorganizou as classes de estímulos bem como seus significados. Porém, resultados análogos não foram reportados para as consequências específicas.Palavras-chave: Matching-to-sample de identidade, consequências específicas, classes de equivalência, reorganização de classes de equivalência, transferência de função, universitários

Seven participants received conditional discrimination training that established the 12 conditional relations A1B1, A2B2, A3B3, A1C1, A2C2, A3C3, D1E1, D2E2, D3E3, D1F1, D2F2, and D3F3. The A stimuli were pictures of faces portraying emotional expressions; the others were arbitrary forms. Correct responses resulted in presentations of class-specific reinforcers, Sr1, Sr2, and Sr3. After training, tests confirmed the formation of ABC and DEF equivalence classes. Further tests then documented the merger of the classes and the emergence of SrB, SrC, SrE, and SrF relations, showing that the class-specific reinforcers were equivalence class members. Finally, participants did Semantic Differential ratings that tested whether the emotional valence of the A stimuli transferred to the arbitrary forms, B and E. The results show that participants’ evaluations of the B and E stimuli were similar to evaluations of the A stimuli made by participants of a control group. This finding is considered as a demonstration that class-specific outcomes can mediate class merger phenomena and the transfer of functions through members of merged classes.

Behavioral momentum theory posits a paradoxical implication for behavioral interventions in clinical situations using differential reinforcement of alternative behavior (DRA): When alternative reinforcers are presented within the same context as the problem behavior, the added reinforcers may decrease the frequency of the behavior but also increase its persistence when the intervention ends. Providing alternative reinforcers in a setting that is distinctively different from that in which the target behavior occurs may avoid or reduce this increase in persistence. The present experiment compared behavioral persistence following standard DRA versus DRA in a different context that was available after refraining from target behavior (differential reinforcement of other behavior; DRO). We arranged a human laboratory model of treatment intervention using computer games and token reinforcement. Participants were five individuals with intellectual disabilities. Experimental phases included (a) an initial multiple-schedule baseline with token reinforcement for target behaviors A and B, (b) an intervention phase with alternative reinforcement using a conventional DRA procedure for A and a DRO-DRA procedure for B, and (c) an extinction phase with no interventions and no tokens. Response rates as proportion of baseline in the initial extinction phase were greater for A than for B for three of five participants. Four participants whose response rates remained relatively high during the extinction phase then received a second extinction-plus-distraction test with leisure items available. Response rates were greater for A than for B in three of four participants. The results indicate that DRO-DRA contingencies may contribute to reduced postintervention persistence of problem behavior.