Various methods were tried in an attempt to obtain a technique for quantifying the gnawing effects of apomorphine on rats. A technique using a restraining tube was developed. Under a 2 milligram per kilogram intraperitoneal injection of apomorphine, four female Long Evans hooded rats were placed on continuous and fixed reinforcement schedules using a gnawable pine block. Subjects would learn to turn their heads away from the gnawable object in order to obtain 15 seconds of gnawing time. The rate of response increased from less than one response in 5 minutes to over 3 responses per minute in 10 one-half hour conditioning sessions. Rates of response stabilized during the last 5 experimental sessions and fixed ratio schedules of up to 5:1 were obtained in five additional 1 '1/ 2 hour sessions.

A series of experiments were conducted with pigeons to investigate the variables responsible for differential postreinforcement pause (PRP) durations found on ratio schedules. In Experiment I, behavior on fixed-ratio (FR) and variable-ratio (VR) schedules were compared to behavior evoked by two interpolated schedules. The addition of a single FR 1 component to the FR 50 baseline schedule reduced the overall PRP to a duration comparable to that found on the VR 50 schedule. The addition of both an FR 1 and an FR 215 component to an FR 50 baseline reduced PRP and IRT durations below those on a VR 50 schedule. Experiments II and III were designed to isolate the conditions under which the smallest ratio component exerts predominant control over PRP duration. The results of Experiment II demonstrated that a local increase in reinforcement density was a necessary, but not sufficient condition for reducing median PRP duration. That is, exposure to a response-independnt increase in reinforcement density attenuated, but did not eliminate the reduction in median PRP duration associated with the interpolated FR 1 component. The results of Experiment III demonstrated that neither random session location of the FR 1 component nor unsignaled presentation of the FR 1 component were necessary conditions for reducing the duration of the PRP. That is, a brief, response-dependent increase in reinforcement density was a sufficient condition for reducing PRP duration given a subject free from historical exposure to response-independent reinforcement. It was concluded that the difference in PRP duration produced by two, comparably-sized, fixed- and variable-ratio schedules is a function of the size of the smallest ratio component present in the reinforcement schedule. More generally, the highest local density of reinforcement controls the overall duration of the PRP on a response-dependent, ratio schedule.

The general purpose of the current study was to evaluate the potency of different categories of reinforcers with young children diagnosed with developmental delays. The participants were two boys and one girl who were between the ages of seven and eight. In Phase 1, we evaluated the reinforcing potency of tokens, edible items, and leisure items by using a progressive ratio (PR) schedule. For two participants, we found that tokens resulted in the highest PR break points. For one participant, edibles resulted in the highest break points (tokens were found to have the lowest break points). In Phase 2, we evaluated the effects of presession access on the break points of edibles and tokens. This manipulation served as a preliminary analysis of the extent to which tokens might function as generalized conditioned reinforcers. During Phase 2, presession access altered the break points of edibles, but not tokens. The findings of the current study suggest that PR schedules may be useful as a means to better assess certain dimensions of tasks and how they affect reinforcer effectiveness (e.g., amount of effort the client is willing to exert, the duration at which the client willing to work, how many responses the client will emit, etc.), and to evaluate to what extent tokens actually function as generalized conditioned reinforcers.

Made available in DSpace on 2016-04-29T13:17:48Z (GMT). No. of bitstreams: 1 Victoria Boni Albertazzi.pdf: 721264 bytes, checksum: 12e708827400af54f3a28bfc8097b7fd (MD5) Previous issue date: 2013-05-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Operant behavior can be placed under stimulus control, and the relationship between discriminated responding and such stimuli can also be controlled by other stimuli, generating the behavioral process named conditional discrimination. Utilizing a rat as a subject, in order to study if it s own behavior could be used as conditional stimulus, controlling choice behavior in a simulateneous discrimination, a procedure was planed based on the proposal by Lionello-DeNolf and Urcuioli (2003). After preliminary training, central lever pressing was placed under the control of a buzzer, in a procedure in which responses emmited in tone cycle accessed a reinforcer (water) and terminated the presentation of the tone, with mean intertrial intervals (ITIs) of initially 30 seconds (range 15-45s), and passing, after two sessions, for 10 seconds mean (range 5-15s). The ratio of lever presses required for water access was gradually increased, and, after reaching FR10, a mixed schedule training was implemented, in which trials with requirements of one or 10 responses were randomically presented. The subject was then placed in a matching-to-sample situation, in which two other levers were presented, and the behavior established in the previous phase accessed comparison stimuli: a blinking and a steady lights, which alternated positions randomically. With the introduction of such condition, central lever press behavior deteriorated; in trials in which comparison stimuli were accessed, choice behavior seemed to be under the control of the position of the stimuli. The role of the ITIs duration in the establishment of simple discriminations was discussed, as well as diferences in the results of such procedures with pigeons and rats / O comportamento operante pode ser colocado sob controle de estímulos antecedentes, e a relação entre o responder discriminado e tais estímulos resultante desse processo pode, por sua vez, ser controlada por outros estímulos, gerando o processo comportamental chamado de discriminação condicional. Utilizando-se de um rato como sujeito, a fim de se estudar se o responder do mesmo poderia servir de estímulo condicional, controlando o comportamento de escolha em uma situação de discriminação simultânea, foi elaborado um procedimento com base no proposto por Lionello-DeNolf e Urcuioli (2003). Após passar por fases preliminares de treino ao bebedouro e seleção de pressão à barra central, esse responder foi colocado sob controle de um tom, em um procedimento no qual o responder em períodos de tom acessava o reforçador e terminava a apresentação do tom, com intervalos entre tentativas (ITIs) tendo inicialmente média de 30 segundos (amplitude 15-45s), e passando, após duas sessões, para média de 10 segundos (amplitude 5-15s). A razão de pressões à barra requeridas para acessar gotas de água foi aumentada, e, após chegar em FR10, foi feito um treino em esquemas mistos, no qual se alternavam, de maneira randômica, tentativas nas quais a água era liberada em CRF e tentativas nas quais a água era liberada em FR10. O sujeito foi então colocado em uma situação experimental de matching-to-sample, na qual foram apresentadas duas outras barras na caixa, e o comportamento estabelecido na fase anterior acessava estímulos comparação: uma luz constante e uma piscante, que alternavam em posição. Com a introdução do procedimento, o responder do sujeito na barra central se deteriorou; nas tentativas em que conseguiu acessar os estímulos comparação, seu comportamento de escolha pareceu estar sob controle da posição dos estímulos. Discute-se o papel do tamanho dos ITIs no estabelecimento das discriminações simples, bem como diferenças nos resultados do procedimento com pombos e ratos

Cette thèse se propose d’étudier la discrimination des comportements par les quantités de réponses itérées. Ce champ de recherche s’inscrit dans celui, plus large, de la discrimination des comportements par les quantités. Nous avons tout d’abord cherché à explorer la façon dont les comportements peuvent être discriminés par des quantités différentes d’itérations de réponses et de quelle façon l’installation ou non de cette discrimination peut être mise en correspondance avec une évolution de l’entropie du débit des réponses itérées. Ensuite, nous avons exploré la dynamique des réponses itérées en fonction de la quantité des itérations requises. Après cela, nous avons cherché à savoir s’il était possible de mettre en correspondance l’existence de dynamiques de réponses propres à des quantités avec l’installation ou non d’une discrimination des comportements par des couples différents composés de ces mêmes quantités. Enfin, en vue d’explorer en quoi l’installation d’’une dynamique des réponses permettait l’installation d’une discrimination des comportements, nous avons perturbé, en modifiant la topographie des réponses requises, l’installation de cette dynamique de réponses, et en avons mesuré les effets sur l’installation de la discrimination de comportements par ces quantités de réponses itérées. Les résultats montrent que l’évolution de l’entropie des débits de réponses itérées est orientée en fonction de l’installation ou non d’une discrimination des comportements par des quantités différentes d’itérations de réponses requises : l’entropie diminue lorsque la discrimination par des quantités de réponses itérées est installée, et augmente dans le cas contraire. Ce résultat n’est vrai que pour les participants ayant atteint au moins une fois le critère de décision que nous nous étions fixé pour juger de l’installation de la discrimination. L’analyse de la dynamique des réponses itérées en fonction de chaque quantité d’itérations requise montre qu’il existe presque systématiquement une dynamique propre à chaque quantité d’itérations de réponses requise, pour tous les participants, cette dynamique de réponses étant également propre à la topographie de la réponse requise. La perturbation de l’installation de la dynamique des réponses a, en outre, un effet sur l’installation de la discrimination des comportements par les quantités d’itérations de réponses. Au regard de ces résultats, nous pouvons conclure qu’il existe une correspondance entre l’installation ou non de la discrimination par des quantités de réponses itérées et l’évolution de l’entropie des débits de ces réponses itérées. Néanmoins, tandis que nous pouvons conclure à la pertinence d’analyser la dynamique des réponses itérées pour en étudier la complexité, la mise en correspondance entre celle-ci et la façon dont chaque quantité d’itérations de réponses prend ou non le contrôle de comportements spécifiques n’est pas possible à ce stade, bien que des pistes vers de futures études aient été proposées, pour explorer plus avant cette relation / This dissertation focuses on discrimination of behaviors by iterated responses, which falls in the scope of field of discrimination by quantities. First, we investigate how discrimination by several couples of iterated responses quantities could be related with the evolution of instantaneous rates of iterated responses entropy. Then, iterated responses dynamic was analyzed for several iterated responses quantities, and response topographies. The third experiment investigates the correspondence between specific dynamics of responses exhibited in fixed-ratio schedules and discrimination by couples of quantities of iterated responses. At last, effects of the disruption of the installation of the dynamic of responses on discrimination by these quantities of iterated responses have been measured. Results show that discrimination by quantities of iterated responses is possible, and that specific dynamics of responses match specific quantities of iterated responses. Although correspondence between such dynamics and discrimination have not been demonstrated, effects of disruption of dynamic of responses installation have been observed suggesting that a link between dynamic of responses and discrimination exists.

Made available in DSpace on 2016-04-29T13:17:51Z (GMT). No. of bitstreams: 1 Henrique Valle Belo Ribeiro Angelo.pdf: 1411502 bytes, checksum: f3f0a741a628ecacfc95ad413171e9a2 (MD5) Previous issue date: 2014-01-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Some metacontingency experiments have been working with intermittent cultural consequences in analogue ways to operant ratio schedules. The transition from lower ratio to higher ratio sometimes were followed by a slight instability in the previous selected cultural practice. Only one experiment showed a ratio strain from continuous production of cultural consequence to an analogue of VR2. In all experiments, the raise in ratio was gradual and only ratios 2 and 3 were used. To access some variables that can contribute to the ratio strain, two experiments were conducted. Subjects had the task to insert numbers in a computer game gaining both individual and/or cultural consequences. The elder subjects were substituted for new ones during all experiments. In both experiments, after a period of selection, the ratio for cultural consequence liberation was increased to 2, than, after a stability criterion has been achieved, the ratio was abruptly increased to 10. In the first experiment there was no changes in the aggregate production when the ratio was raised and then the metacontingency was discontinued (analogue of operant extinction). The pattern of production continued for a long period of extinction until the pattern dismisses. The second experiment showed a ratio strain when the ratio was raised from 2 to 10. The results were discussed in terms of different forms of cultural transmission, the format of rules generated by the subjects and the contact with the cultural consequence / Alguns experimentos sobre metacontingências têm trabalhado com consequências culturais intermitentes de formas análogas a esquemas operantes de razão. A transição de razões mais baixas para razões mais altas algumas vezes foram seguidas por uma leve instabilidade na prática cultural previamente selecionada. Somente um experimento mostrou uma distensão da razão na mudança de produção contínua da consequência cultural para um análogo de VR2. Em todos os experimento, o aumento na razão foi gradual e somente as razões 2 e 3 foram usadas. Para avaliar algumas variáveis que podem contribuir para a distensão da razão, dois experimentos foram conduzidos. Os participantes tinham a tarefa de inserir números em um jogo de computador liberando tanto consequências individuais quanto culturais. Os participantes mais antigos foram substituídos por novos durante todos os experimentos. Em ambos os experimentos, depois de um período de seleção, a razão para a liberação da consequência cultural foi aumentada para 2, então, depois de um critério de estabilidade ser atingido, a razão foi abruptamente aumentada para 10. No primeiro experimento não houve mudanças na produção agregada quando a razão foi aumentada e a metacontingência foi então descontinuada (análogo de extinção operante). O padrão de produção contínua por um longo período de extinção até que o padrão deixou de ocorrer. O segundo experimento mostrou uma distensão na razão quando a razão foi aumentada de 2 para 10. Os resultados foram discutidos em termos de diferentes formas de transmissão cultural, o formato das regras geradas pelos participantes e o contato com a consequência cultural

Reinforcer assessments have largely relied on the use of progressive ratio (PR) schedules to identify stimuli that function as reinforcers. PR schedules evaluate the reinforcing efficacy of a stimulus by measuring the number of responses produced in order to access a stimulus as the number of required responses increases. The current evaluation extends the literature on reinforcer assessments by measuring responding under a progressive force (PF) schedule, in addition to progressive ratio requirements. We compared responding under PR and PF schedules with two children with autism using a multielement design embedded within a reversal experimental design. Results were mixed and implications for further development of reinforcer assessment methods (particularly PF schedules) are discussed.