Nos estudos do desamparo aprendido em humanos os resultados experimentais tem sido inconsistentes. Isso provavelmente devido a ocorrencia, na sessao de incontrolabilidade, entre outras variaveis, de contiguidades sistematicas entre o termino do estimulo aversivo e a resposta imediatamente precedente, mimetizando uma condicao de controle, embora acidental. Com o objetivo geral de estabelecer um procedimento que permitisse controle experimental suficiente para que fosse analisado o efeito de uma historia de incontrolabilidade sobre a aprendizagem de uma nova resposta operante em sujeitos humanos, bem como a prevencao (imunizacao) desse efeito, foram realizados tres experimentos. O primeiro deles demonstrou o controle operante sob tres contingencias de reforcamento negativo (sequencias variaveis, labirinto e discriminacao de formas geometricas), o que permitiu verificar o efeito da ausencia de controle sobre uma nova aprendizagem operante (Experimento 2 desamparo aprendido) e o efeito da ausencia de controle, apos historia de controle, sobre uma nova aprendizagem operante (Experimento 3 imunizacao). No Experimento 2, dois grupos de participantes foram expostos a sons aversivos (Grupos C e I) e um nao foi manipulado (Grupo N). Para os participantes do Grupo C, a interrupcao de um som agudo era contingente a emissao de sequencias variaveis; para os participantes do Grupo I, a duracao do som era independente das respostas emitidas. Os sujeitos do Grupo Incontrolavel foram divididos em dois subgrupos de acordo com a presenca ou a ausencia de indicacoes na tela (Ip e I). Na sessao de incontrolabilidade foram manipuladas algumas variaveis a fim de evitar a selecao acidental da resposta mensurada (duracao do estimulo; numero de tentativas; custo da resposta e instrucao inicial). Apos essa fase, todos os participantes foram submetidos a uma contingencia de resolucao de um labirinto associado a um som. No Experimento 3, um Grupo Precontrole (P) foi acrescido a triade do Experimento 2. A contingencia de fuga discriminação foi realizada na fase pre-tratamento sendo associada a um som. Na fase de teste os participantes dos Grupos C, N e P apresentaram menor latencia e maior numero de respostas corretas em comparacao aos grupos incontrolaveis. Entre esses ultimos, foi verificada uma correlacao negativa entre a frequencia de contiguidades no tratamento e o desempenho no teste. Os participantes do Grupo I apresentaram baixa frequencia de contiguidades no tratamento e latencias e falhas mais elevadas no teste; os do Grupo Ip mostraram padrao intermediario. Esses resultados replicam o desamparo aprendido e a imunizacao desse efeito em humanos, sugerindo que os pocedimentos estabelecidos foram adequados para o estudo desses dois efeitos e demonstram o papel da selecao acidental, durante a sessao de incontrolabilidade, como impeditivo da verificacao do efeito no teste (Grupo Ip). O papel das indicacoes na tela, os parametros utilizados e a presenca de contiguidades sistematicas foram discutidos / The results of learned helplessness studies with humans have been inconsistent. This is probably due to the systematic contiguity between the end of the aversive stimulus and the immediately preceding response during the uncontrollability session, which mimics an accidental control condition. Three experiments were conducted to establish a procedure with adequate experimental control to analyze the effects of an uncontrollability history upon learning of a new operant response in humans, as well as the prevention (immunization) of this effect. The first experiment demonstrated operant control under three negative reinforcement contingencies (variable sequences, maze, and discrimination of geometric forms), which allowed verifying the effect of the absence of control upon learning of a new operant response (Experiment 2 learned helplessness) and the effect of the absence of control, after a history of controllability, upon learning of a new operant response (Experiment 3 immunization). During the uncontrollability session, a number of variables were manipulated to avoid the accidental selection of the response being measured (duration of the stimulus, number of trials, response cost, and initial instructions). In Experiment 2, two groups were exposed to aversive tones (groups C and U) and one group was not (group N). For group C, the interruption of a high-pitch tone was contingent on the emission of variable sequences; for group U, the duration of the tone was response independent. Group U was further divided into two subgroups, according to the presence or absence of a hint on the screen (Up and U). After this manipulation, all participants had to solve a maze that was presented along with a tone. In Experiment 3, a pre-control group (P) was added to the ones in Experiment 2. The escape contingency for discriminating geometric forms was presented in the pre-treatment phase along with a tone. The results of the test phase indicated shorter latencies and a greater number of responses for groups C, N, and P, in comparison to the uncontrollable groups. For the latter groups, there was a negative correlation between the frequency of contiguities in the treatment phase and performance during the test phase. There was a low frequency of contiguities during treatment, and longer latencies and more errors during the test for Group U; an intermediate pattern was observed for Group Up. These results replicate the learned helplessness and immunization effects in humans, and suggest that this procedure is adequate to study these phenomena. The results also indicate that accidental selection during the uncontrollability session may eliminate the learned helplessness effect during the test (Group Up). The effects of the hints on the screen, the schedule parameters, and the presence of systematic contiguities are further discussed

Much research has focused on the development of methods of measuring preference for stimuli. These methods have shown to be an accurate and valid way to identify potential reinforcers. However, these methods have only been conducted with tangible stimuli and have not been extended to non-tangible stimuli or activities, potentially because these types of stimuli are not appropriate for current preference assessment presentation methodologies. This study used a single stimulus presentation preference assessment to identify preferred activities for two adults with developmental disabilities. Two measures (duration of engagement and indices of happiness) were collected to identify preferred stimuli. For both participants, there were differences in happiness measure between activities. The engagement measure only produced differentiated results for one participant. Reinforcer assessments were conducted to determine if the measures of preference were able to identify high preference stimuli that functioned as more effective reinforcers more than stimuli identified as low preference. Both participants exhibited high rates of an arbitrary response during all conditions of the reinforcer assessment. Therefore, the reinforcer assessments did not validate the results of the preference assessments.

The benefits gained by the presentation of environmental enrichment (EE) to captive animals are widely recognized. Few studies have, however, studied how to maximize the effect of EE. Repeated presentations of EE may cause a reduced interest towards the EE device, called habituation. To study the effect of habituation towards EE, behavioural data from 14 captive Sloth bears (Melursus ursinus) were collected during two different EE treatments. In treatment one, honey logs were presented for five consecutive days (ConsEE). In treatment two, the logs were presented every alternative day for five days (AltEE). The different treatments both showed a significant effect on responsiveness toward the EE, however, leaving gap days inbetween presentations in AltEE showed no reliable reduction in habituation. Both treatments significantly reduced stereotypies, however, only ConsEE reduced levels of stereotypies long term. Explorative behaviours, which are the most prominent behaviours in the wild, increased during both treatments. This is consistent with previous findings (Fischbacher & Schmid 1999, Grandia et al. 2001) that EE increases natural behaviours, which has been desribed as an indication of improved welfare (Carlstead et al. 1991 etc.). Other behavioural categories such as social and passiva behaviours were unaffected by the EE presentations. THe results show that it is possible to increase the effectiveness of EE by simple means in order to ensure animal welfare.

<p>The benefits gained by the presentation of environmental enrichment (EE) to captive animals are widely recognized. Few studies have, however, studied how to maximize the effect of EE. Repeated presentations of EE may cause a reduced interest towards the EE device, called habituation. To study the effect of habituation towards EE, behavioural data from 14 captive Sloth bears (<em>Melursus ursinus</em>) were collected during two different EE treatments. In treatment one, honey logs were presented for five consecutive days (ConsEE). In treatment two, the logs were presented every alternative day for five days (AltEE). The different treatments both showed a significant effect on responsiveness toward the EE, however, leaving gap days inbetween presentations in AltEE showed no reliable reduction in habituation. Both treatments significantly reduced stereotypies, however, only ConsEE reduced levels of stereotypies long term. Explorative behaviours, which are the most prominent behaviours in the wild, increased during both treatments. This is consistent with previous findings (Fischbacher & Schmid 1999, Grandia et al. 2001) that EE increases natural behaviours, which has been desribed as an indication of improved welfare (Carlstead et al. 1991 etc.). Other behavioural categories such as social and passiva behaviours were unaffected by the EE presentations. THe results show that it is possible to increase the effectiveness of EE by simple means in order to ensure animal welfare.</p>

Title from PDF of title page. / Document formatted into pages; contains 49 pages. / Thesis (M.A.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Much research has focused on the development of methods of measuring preference for stimuli. These methods have shown to be an accurate and valid way to identify potential reinforcers. However, these methods have only been conducted with tangible stimuli and have not been extended to non-tangible stimuli or activities, potentially because these types of stimuli are not appropriate for current preference assessment presentation methodologies. This study used a single stimulus presentation preference assessment to identify preferred activities for two adults with developmental disabilities. Two measures (duration of engagement and indices of happiness) were collected to identify preferred stimuli. For both participants, there were differences in happiness measure between activities. The engagement measure only produced differentiated results for one participant. / ABSTRACT: Reinforcer assessments were conducted to determine if the measures of preference were able to identify high preference stimuli that functioned as more effective reinforcers more than stimuli identified as low preference. Both participants exhibited high rates of an arbitrary response during all conditions of the reinforcer assessment. Therefore, the reinforcer assessments did not validate the results of the preference assessments. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Functional Analysis is an important component of creating a treatment plan for individuals with autism. A concern of functional analysis is that it might not match the natural environment in which the problem behavior occurs. Dimensions such as varying reinforcement duration and session length may affect response rates during functional analyses in natural settings. This study investigated if varying reinforcement duration and session length during functional analyses would affect the identification of the function of problem behavior across assessors, and the intervention designed based on the functional analyses would be effective in reducing stereotypic behavior and teaching communicative skills of an adolescent with autism at home. An alternating treatment design was used to conduct functional analyses and an ABA design with generalization probes was used to test the effectiveness the function-based intervention. Results indicated that the participant's stereotypic behavior was maintained by automotive reinforcement. The intervention developed based on the function of the stereotypic behavior was found to be effective in reducing the stereotypy and teaching communicative behavior.

Cognitive theories of timing and conditioned reinforcement provide two different theoretical perspectives on choice between delayed rewards. The primary objective of this research was to identify the process that generates choice in the concurrent-chains procedure and to characterize its relationship with temporal control. Experiments 1-3 investigated the relationship between the dynamics of pigeons’ preference and temporal control in concurrent chains using an arrangement in which the delays to reinforcement changed unpredictably across sessions. To obtain convergent measures of choice and timing behavior, occasional ‘no-food’ terminal links lasted longer than the schedule values and ended without reinforcement. Measures of choice (log initial-link response ratios) and timing (start and stop times from no-food terminal links) stabilized within individual sessions. Sensitivity of log response ratios to relative immediacy increased as initial-link duration decreased or absolute terminal-link delays increased, but absolute initial- and terminal-link duration did not affect temporal control. Residual covariation analyses of log response ratios with log start and stop time ratios confirmed that measures of choice and timing were interdependent. Experiments 4 and 5 used concurrent-chains procedures in which immediacy, magnitude (and probability, in Experiment 5) ratios for left and right keys were 2:1 or 1:2, determined across sessions by independent, random series. Experiment 6 was a concurrent schedule in which relative reinforcement rate and magnitude were 2:1 or 1:2, determined the same way. Multiple regression analyses showed that pigeons’ response allocation in Experiments 4-6 was sensitive to multiple dimensions of reinforcement. Levels of preference within individual sessions and initial links or interfood intervals was more extreme when all dimensions favored the same key than when at least one dimension favored each key, consistent with assumptions of the generalized matching law. Within individual sessions, changes in response allocation in all experiments tended to be abrupt, consistent with the assumptions of Rate Estimation Theory (Gallistel & Gibbon, 2000). A decision model that posits a comparison between delayed outcomes with a criterion delay (Grace & McLean, 2006) described initial-link responding in Experiments 1-3. A modified decision model in which outcome expectancy is compared to an expectancy criterion described responding in Experiments 4-6.

abstract: The present study used a multiple baseline design across settings to examine the effects of using an iPad as an alternative reinforcer on self-injury and aggression when reinforcement for appropriate communication was denied following Functional Communication Training in an adolescent with Autism Spectrum Disorder (ASD), Intellectual Disability (ID), and severe aggression. The study also assessed collateral effects of the intervention on the use of self-management to control aggression. Data indicate the use of an iPad as an alternative reinforcer decreased the duration of self-injury and physical aggression in an adolescent in a big box store, grocery store, and classroom. Instances of self-injury and aggression remained low during maintenance sessions and a six month post-hoc analysis. Collateral gains in self-management were made during treatment and maintenance sessions. / Dissertation/Thesis / Doctoral Dissertation Special Education 2014

Stimulus preference assessments have been shown to identify stimuli that are likely to function as reinforcers for individuals with disabilities. It is important to identify these stimuli to increase the effectiveness of interventions. The ability to conduct a stimulus preference assessment is a skill that parents and caregivers should have. Research on training preference assessments is limited to staff, teachers, and students. The following study evaluated the effectiveness of video modeling to teach caregivers to conduct paired stimulus preference assessments. The results showed that video modeling was effective and that the results maintained during a one week follow up.

The effects of two consequence delivery methods on task acquisition were evaluated within a multi-element design. A typical 3 year-old child and a 4 year-old child with autism participated in this study. The task for both children was to select a picture after the experimenter said its name. The consequence in one condition consisted of the experimenter handing the edible item to the children. The consequence in the other condition consisted of the children retrieving the edible item directly from the apparatus, located in a crevice underneath each picture. Results show slightly quicker acquisition in the condition where children retrieved the edible consequence. However, it is possible that other variables had greater influence on the task acquisition.