Made available in DSpace on 2016-07-27T14:20:16Z (GMT). No. of bitstreams: 1 Berta Baltazar Elias.pdf: 285163 bytes, checksum: 3fd879852dd982563e5e00f33d711e85 (MD5) Previous issue date: 2005-12-21 / A chained probabilistic choice procedure was used to observe if human participants were sensible to the manipulation of the probabilities of reinforcement. In this procedure there was an initial screen showing two stimuli a circle and a triangle (initial chain). Choices in the circle led to a second screen (final chain) with a stimulus, and triangle choices opened a second screen with 4 stimuli. After choosing the final chain the participant could score or not depending on the value of the probabilistic pair programmed to the circle or triangle choices. Three pairs of probabilistic choice were used (0. 10-0. 10, 0.50-0.50 e 0.90-0.90) and the change between them allowed 6 different sequences. Each one of the 30 participants went through a sequence that, beyond the reinforcement probabilities, also had initial and final (extinction) base line sessions. A criterion of 10% of establishment of preference between the last sessions was used for the change of probability. In the condition that the probabilistic pair was 0.10-0.10 all the participants got an instruction to choose the circle. Was observed that the participants did not discriminate the different probabilities of reinforcement and that even though with a low probability (0.10) the instruction did not controlled the preference of the participants. Experiment 2 aimed to verify if the number of trials to reinforcement of the final chain controlled the preference, and another 5 participants were exposed to 4 different probabilistic pairs. Each participant was exposed to the pair for 3 sessions with 40 trials each. Thus, each participant went through exactly 12 experimental sessions always in the same row: 0.010-0.00, 0.00-0.10, 0.90-0.00 and 0.00-0.90; the former probabilistic pair is always the triangle and the latter the circle. The data of the second experiment shows the established control by the reinforcement and not by the number of trials. / Um procedimento de escolha probabilística encadeada foi utilizado com o intuito de se observar se participantes humanos foram sensíveis à manipulação das probabilidades de reforçamento. Neste procedimento havia uma tela inicial com dois estímulos um círculo e um triângulo (elo inicial). Escolhas no círculo dispunham uma segunda tela (elo terminal) com um estímulo e escolhas no triângulo dispunham uma segunda tela com 4 estímulos. Depois de escolher no elo terminal o participante podia ou não ganhar pontos conforme o valor do par probabilístico programado para utilizados (0.10-0.10, 0.50-0.50 e 0.90-0.90) e a permuta entre elas possibilitou 6 diferentes seqüências. Cada um dos 30 participantes passou por uma seqüência que além das probabilidades de reforçamento ainda tinha sessões de linha de base inicial e final (extinção). Um critério de 10% de estabilidade da preferência entre as duas últimas sessões foi utilizado para mudança de probabilidade. Na condição em que estava em vigor o par probabilístico 0,10-0,10 todos os participantes receberam uma instrução para escolherem o círculo.Observou-se que os participantes não discriminaram as diferentes probabilidades de reforçamento e que mesmo com uma probabilidade baixa(0,10) a instrução não controlou a preferência dos participantes.No experimento 2, que teve como objetivo verificar se o número de alternativas para reforçamento no elo terminal controlava a preferência, outros 5 participantes foram expostos a 4 diferentes pares probabilísticos. Cada participante exposto ao par por 3 sessões com 40 tentativas cada. Assim, cada participante passou por exatamente 12 sessões experimentais sempre na mesma ordem: 0.010-0.00, 0.00- 0.10, 0.90-0.00 e 0.00-0.90; sendo que a primeira probabilidade do par sempre se refere ao triângulo e a segunda ao círculo. Os dados do segundo experimento deixam claro o controle estabelecido pelo reforço e não pelo número de alternativas.

Parental participation in parent training programs is necessary for success in behavioral parent training. Prior literature has demonstrated probabilistic reinforcement as an effective intervention for improving a wide variety of behaviors. In the present study, a probabilistic reinforcement program (i.e., lottery) was implemented in order to evaluate its efficacy as part of a behavioral parent training program. The behaviors targeted for increase included attendance, participation, homework completion, and performing role-plays or completing in-class assignments for two 10 week Tools for Positive Behavior Change courses. Participants earned lottery tickets for each of the dependent measures, and drawings took place at the end of each class. An alternating treatments design was employed to determine any differences in performance on the dependent measures between baseline and lottery sessions. Results showed that participants attended and participated more with parent training under the conditions of a lottery compared to baseline class sessions although the effect was minimal; furthermore, this effect was observed more clearly for one of the two classes. Further research is needed to explore the effect of a lottery intervention on parent participation in parent training programs.