Falk's pivotal 1961 study showed that rats would drink excessive amounts of water when exposed to a time based schedule of reinforcement. Since then, schedule-induced drinking or polydipsia, has been demonstrated with several species and with a variety of different behaviors. Rats, the most commonly used animal, have been shown to drink excessive amounts of water under a variety of different time based schedules of reinforcement; exclusively during a free operant procedure. The current study shows that water drinking can be induced during a discrete trial procedure, and instead of using a time-based schedule of reinforcement, this study used a variable-ratio schedule of reinforcement. The results showed that excessive water drinking was induced under these conditions with a canine.

Made available in DSpace on 2016-04-29T13:18:00Z (GMT). No. of bitstreams: 1 Dissertacao Thais Martins Sales.pdf: 1293785 bytes, checksum: 6161405c79ed51ec0c3dacacebe67ee1 (MD5) Previous issue date: 2006-05-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was an attempt to investigate possible relations between responding that is reinforced according to schedules based on a temporal parameter and performing other activities to which no reinforcement contingencies are programmed. These activities have been called adjunctive behavior, collateral behavior or interim activities. Two questions guided this study: a) is there any difference in response rate, average time between reinforcers, and percentage of reinforced responses when an FI schedule or a DRL schedule is in force, if the subject can engage in other activities; b) are typical sequential patterns developed between responses when these schedules are in force? Four male food deprived rats were subjects of this experiment. The apparatus was an experimental box with seven chambers in which subjects could perform different activities, such as bar pressing, eating, running, drinking, and wood-chewing. For two subjects, bar pressing was reinforced according to three DRL schedules (DRL 4s, DRL 5s, and DRL 20s). One of the subjects was first kept in the chamber with the bar and food dispenser and then was allowed to access the other chambers, the other was first allowed to access the other chambers and then was kept in the chamber with the bar and food dispenser. For the other two subjects, bar presses were reinforced according to two FI schedules (FI 5s and FI 10s). One of the subjects first had access to all chambers and then was kept in the chamber with the bar and food dispenser, and the other was kept in the chamber with the bar and food dispenser during the whole experiment. Bar presses, reinforcement deliveries, and occupancy of chambers were recorded. Results show there was a difference in response rate, average time between reinforcers, and percentage of reinforced responses in both schedules, depending on the access condition, mainly when responses were reinforced according to schedules higher than FI 5s and DRL 4s. Higher response rates, lower average time between reinforcers and higher percentage of reinforced responses were observed for the DRL subjects when access was possible than when it was not possible, and higher response rates, higher average time between reinforcers and higher percentage of reinforced responses were observed for the FI subjects when access was possible than when it was not possible. No typical sequential patterns were observed when access was possible and either of the two studied schedules was in force. Results are discussed in terms of possible controlling variables to performing activities other than bar pressing when responding is being reinforced according to FI and DRL schedules / O presente trabalho é uma tentativa de investigação de possíveis relações entre o responder reforçado segundo dois esquemas de reforçamento que envolvem parâmetros temporais e o engajamento em atividades para as quais não há reforço programado, chamadas de atividades ínterim, comportamento adjuntivo ou comportamento colateral. Duas perguntas dirigiram a realização deste trabalho: a) há diferença na taxa de respostas, tempo médio entre reforços e porcentagem de respostas reforçadas segundo esquemas DRL e FI, caso haja possibilidade de engajamento em outras atividades? e b) alguma seqüência típica de engajamento em outras atividades é formada no intervalo entre respostas reforçadas segundo estes esquemas? Os sujeitos do experimento foram quatro ratos machos privados de alimento. Foi utilizada uma caixa experimental com sete compartimentos, nos quais era possível o engajamento em diferentes atividades: pressionar a barra, comer, beber, correr, roer madeira. Dois sujeitos tiveram as respostas de pressão à barra reforçadas segundo esquemas DRL com três valores diferentes (4s, 9s e 20s). Um deles passou, primeiro, por uma condição na qual o acesso a todos os compartimentos era permitido, chamada de aberta, e, segundo, por uma condição na qual era mantido no compartimento onde havia a barra e o comedouro, chamada de fechada, e o outro sujeito passou, primeiro, pela condição fechada e, segundo, pela condição aberta. Os outros dois sujeitos tiveram as respostas de pressão à barra reforçadas segundo esquemas FI com dois valores diferentes (5s, 10s). Um sujeito passou primeiro pela condição aberta e, depois, pela condição fechada e o outro passou apenas pela condição fechada. As pressões à barra, os reforços e a permanência nos compartimentos foram registrados. Os resultados mostraram que houve diferença na taxa de respostas, tempo médio entre reforços e porcentagem de respostas reforçadas em função da condição de acesso, especialmente quando as respostas de pressão à barra foram reforçadas segundo o esquema DRL 9s e DRL 20s, para os dois primeiros sujeitos, e segundo o FI 10s, para os outros dois sujeitos. Na condição aberta com esquema DRL em vigor, observou-se uma menor taxa de respostas, menor tempo entre reforços e maior porcentagem de respostas reforçadas do que na condição fechada, com o mesmo esquema em vigor. Na aberta com esquema FI em vigor, observou-se uma menor taxa de respostas, maior tempo entre reforços e maior porcentagem de respostas reforçadas do que na condição fechada, com o mesmo esquema em vigor. Seqüências típicas de engajamento em outras atividades não foram observadas quando o acesso era possível e o responder era reforçado segundo os esquemas FI e DRL. Os resultados são discutidos em termos de possíveis variáveis que controlam o engajamento em outras atividades, quando respostas são reforçadas segundo estes dois esquemas