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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Effects of Click + Continuous Food Vs. Click + Intermittent Food on the Maintenance of Dog Behavior.

Wennmacher, Pamela L. 05 1900 (has links)
There is disagreement among clicker trainers on whether or not food should be delivered every time the clicker (conditioned reinforcer) is used. However, presenting a conditioned reinforcer without food can weaken the strength of the conditioned reinforcer and also disrupt its discriminative stimulus function. A within subjects reversal design was used with 2 dogs to compare the behavioral effects of continuous pairings (C+F condition) vs. intermittent pairings (C+C+F condition) of the clicker with food. Results show that the C+C+F condition affects the frequency, accuracy, topography, and intensity of the behavior, and increases noncompliance and other unwanted behaviors. This study adds to the literature by evaluating the effects of conditioned reinforcement in an applied setting using discrete trials without undergoing extinction.
72

A parametric analysis of the immediate and subsequent effects of response restriction on hand mouthing.

Soderlund, Michael J. 05 1900 (has links)
The immediate and subsequent effects of different durations of response restriction were evaluated in a multiple schedule design. Response restriction components of 15, 30, and 60 minutes were conducted between 15 minute alone components. Levels of responding subsequent to the termination of response restriction procedures were compared to free operant levels prior to the implementation of response restriction. Responding during response restriction components reduced to near zero levels. Subsequent levels of responding were similar to or exceeded free operant baseline levels. Results are discussed in terms of potential operant mechanisms responsible for levels of responding subsequent to response restriction.
73

The Effectiveness of Denton State School's Developmental Evaluation Form in Evaluating an Operant Training Program for Severely Retarded Boys

Graham, Malcolm J. 05 1900 (has links)
The problem of this study was to evaluate Denton State School's Developmental Evaluation Form as it is now being used in their operant conditioning techniques in certain basic self-help areas, and to suggest a more effective and informative method of scoring the Evaluation Form. The present method of scoring this evaluation form requires that -all items at each developmental level be passed in order to receive credit for that level. No partial credit is given at any level. This method of scoring yields a developmental level at which. the individual is functioning. It does not, however, point out the total overall development of the individual. The present type of basal developmental scoring is not as discriminating as far as picturing an individual's total development as the one which will be suggested.
74

The Effects of Reinforcer Distribution During Response Elimination on Resurgence of an Instrumental Response

Schepers, Scott Timothy 01 January 2014 (has links)
Resurgence is the relapse of an extinguished instrumental behavior that can occur when an alternative behavior that was introduced to replace it is itself extinguished. In a typical resurgence experiment, rats are trained to make a response (R1) for food reinforcers. In a second phase, responses on R1 are no longer reinforced, but a new response (R2) is introduced and responses on it are reinforced. During a third phase, reinforcement for R2 is removed and behavior on R1 often returns (or "resurges") despite remaining on extinction. The current experiments were designed to examine the effects of the temporal distribution of reinforcers delivered during Phase 2 on later resurgence. The role of these alternative reinforcers is central to theories that have been proposed to account for resurgence. The experiments provided a special opportunity to contrast predictions made by the Shahan-Sweeney Model (Shahan & Sweeney, 2011) and a contextual account of resurgence (Winterbauer & Bouton, 2010). Experiments 1 and 2 examined resurgence when alternative reinforcement during Phase 2 was delivered according to the same set of daily reinforcement schedules presented in different orders. That is, one group received rich reinforcement rates that were gradually thinned to leaner ones (Group Thinning) and another group received lean rates that were gradually increased to richer ones (Group Reverse Thinning). Both procedures weakened resurgence compared to that in a group that received the richest rate (a variable interval, or VI 10-s schedule that arranged for a reinforcer to be available for a response every 10s on average) during all of the Phase 2 sessions. However, the forward thinning procedure was more effective than the reverse thinning procedure at eliminating the resurgence effect. Experiment 3 examined resurgence when alternative reinforcement was only available for R2 during every other session. The results indicated that daily alternations of a VI 10-s schedule with an extinction schedule for R2 weakened resurgence compared to groups that either received the same average rate over the entire phase (VI 17.5-s) or that received the same terminal rate (VI 10-s) in every session. The Shahan-Sweeney model cannot account for several of the current results. Instead, the results are most consistent with a contextual account of resurgence. That is, resurgence can be conceptualized as an ABC renewal effect in which extinguished R1 behavior returns when an animal is removed from an extinction "context" provided by R2 reinforcement. Lean reinforcement rates at any time during Phase 2 allow the animal to learn to inhibit R1 under conditions that generalize to the extinction conditions that prevail during the resurgence test. The results also suggest that experience with alternating extinction sessions or lean reinforcement rates close to the final resurgence test are especially effective at eliminating the resurgence effect.
75

Role of HDAC inhibition and environmental condition in altering phases of amphetamine self-administration

Arndt, David L. January 1900 (has links)
Doctor of Philosophy / Psychological Sciences / Mary E. Cain / Gene-environment interactions play a significant role in drug abuse and addiction. Epigenetics (the study of how environmental stimuli alter gene expression) has gained attention in recent years as a significant contributor to many behavioral phenotypes of drug addiction. The current study sought to determine if differential rearing conditions can alter a specific epigenetic mechanism, histone deacetylase (HDAC), and how HDAC inhibition can affect drug-taking and drug-seeking behaviors differently among enriched, isolated, or standard-housed rats. Ninety male Sprague-Dawley rats were reared for 30 days in enriched (EC), isolated (IC), or standard (SC) conditions prior to amphetamine (0.03, 0.05, 0.1 mg/kg/infusion, i.v.) self-administration, extinction, or reinstatement sessions. Trichostatin A (TsA; 0.3 mg/kg, i.v.), an HDAC inhibitor, was injected 30 min prior to drug-taking or drug-seeking sessions. Results indicated that EC rats self-administered less amphetamine (0.03 mg/kg/infusion) than IC rats. No significant effects of TsA administration were found on general self-administration for any of the three amphetamine doses. While enrichment facilitated the extinction of active lever pressing, there was also a mild facilitation of extinction in IC-TsA rats compared to IC-vehicle counterparts. Lastly, TsA administration decreased cue-, but not drug-induced reinstatement, with IC-TsA rats exhibiting significantly attenuated cue-induced reinstatement compared to IC-vehicle rats. These findings suggest that differential rearing can alter HDAC mechanisms that can change drug-seeking behaviors, particularly in rats reared in isolated conditions. While TsA-induced HDAC inhibition may be less protective against general amphetamine self-administration, it may decrease drug-seeking tendencies during relapse that are induced by the reintroduction of contextual environmental cues heavily associated with drug reward.
76

The Effects of Behavioral Charting, Token Reinforcement, and Social Reinforcement on the Production Rates of Sheltered Workshop Clients

Moore, Eugenia M. 12 1900 (has links)
This investigation concerned the effects of behavioral charting, token reinforcement, social reinforcement, and combinations of behavioral charting with token or social reinforcement, upon the production rates of sheltered workshop clients. The differential effects of these reinforcement methods were investigated by arranging for the application of each reinforcement mode in a sheltered workshop setting and comparing the mean production rates achieved by two groups of sheltered workshop clients under each reinforcement condition. The findings derived from this sample led to the conclusion that positive reinforcement, and specifically social reinforcement used both alone and in combination with behavioral charting, can be a very effective mode of reinforcement for sheltered workshop clients. It was suggested that more attention might be devoted in rehabilitation facilities to using the simpler and more readily available forms of reinforcement which behavioral charting and social reinforcement represent.
77

Efeito de enriquecimento ambiental na auto-administração oral de álcool em ratos / Influence of environmental enrichment in alcohol oral self-administration in rats

Bernardes, Ana Martins Torres 18 April 2008 (has links)
Esta pesquisa estuda a relação entre o ambiente em que ratos se desenvolvem e a auto-administração de etanol (ET) na idade adulta. Usualmente, a pesquisa comportamental com animais em laboratório utiliza sujeitos mantidos em isolamento em caixas individuasi (I). Uma das espécies mais usadas é o rato, um animal social que em habitat natural vive em colônias. Que efeitos tem o isolamento nesses ratos? Propõe-se que a baixa disponibilidade de reforçadores alternativos seja um dos fatores determinantes do abuso de drogas. Algumas pesquisas mostraram que o isolamento, que caracteriza ambientes de baixa disponibilidade de reforçadores, leva a um aumento no consumo de morfina, anfetamina e barbital em relação a ratos criados em ambientes com maior disponibilidade de reforçadores (AE), e mais ET comparados a animais criados em grupo. No entanto, outras pesquisas observaram que animais criados em AE consomem mais ET do que animais criados em isolamento. Utilizando medidas de comportamento operante de ingestão de ET, o presente experimento visou observar se a disponibilidade de reforçadores no ambiente de criação e/ou concorrentes ao álcool no ambiente experimental altera o consumo, o valor reforçador e a elasticidade da demanda dessa droga. Ratos Wistar machos foram criados em I ou em AE. O consumo e o valor reforçador do ET foram medidos nos esquemas operantes de FR2 e Razão Progressiva (RP), respectivamente. O ET foi introduzido por fade in/fade out de sacarose, culminando numa solução de ET 10% adoçada com sacarina 0,25%. O teste de RP foi conduzido para solução de ET, depois para sacarina. Os animais foram submetidos também ao teste de ansiedade no labirinto em cruz elevado e sua atividade motora foi estimada em caixa de atividade. Os ratos I consumiram e responderam significativamente mais pelo ET comparados aos ratos AE. Os ratos I evidenciaram aumento do valor reforçador do ET, mas não da sacarina, medido em RP, quando comparados aos do grupo AE. Os grupos AE e I não apresentaram diferenças significativas em ansiedade. Os animais do grupo I mostraram-se significativamente mais ativos do que os do grupo AE. A elasticidade da demanda foi medida em um modelo concorrente no qual uma alternativa dispensava solução de ET e a outra uma solução isocalórica ao ET, e as exigências em VR foram aumentadas progressivamente, primeiro para a alternativa isocalórica, e depois para o ET. A introdução de reforçadores concorrentes alterou o consumo de ET dos animais criados em I sem alterar o comportamento dos animais criados em AE. A criação nos diferentes ambientes não alterou a elasticidade da demanda por ET, porém alterou a elasticidade da demanda pelo reforçador concorrente. Os animais do grupo I, apesar de consumirem significativamente mais da solução alternativa ao ET, apresentaram uma demanda mais elástica em relação a esse reforçador quando comparados aos do grupo AE. A dependência de drogas, e do álcool em especial, pode e deve ser entendida dentro das mesmas leis que regulam o comportamento em geral, e os modelos de escolha são essenciais para essa compreensão. / This research investigated the influence of different types of rearing environment on ethanol (ET) self-administration in adult rats. Usually behavioral research is conducted using isolated animals (I), one widely used animal is the rat, a social animal that under normal circumstances lives at large colonies. What kind of effects could this unnatural isolation have? It has been proposed that one major factor in drug abuse and dependence is the lack for alternative reinforcers to the drug. Animals raised in limited environments with few reinforcers (I) consume more morphine, amphetamine and barbital than animals raised in enriched environments (EE), which present different opportunities of behavior. These isolated rats have also been shown to consume more ET; however, there are some contradictory results within studies: some have even shown enhanced consumption in EE rats. The present study proposed to investigate whether differential presence of reinforcers during rearing or concurrently to the presentation of ET would influence its consumption, reiforcer value and demand elasticity. Male Wistar rats were raised either in EE or I. Using a self administration paradigm, consumption and reiforcer value were estimated in a FR2 and Progressive Ratio (PR), respectively. ET was introduced by fade in as sucrose was faded out from the solution, resulting in a 10% ET solution sweetened with saccharin 0,25% as the reinforcer solution. The PR procedure was first conducted using the ET solution and then with just the saccharin solution (vehicle). Anxiety was estimated using the elevated cross maze model, and motor activity was accessed in the activity box. I rats consumed and responded more for ET than EE rats in FR2 schedule. They also presented higher reiforcer value for ET in the PR paradigm, but not for saccharin, when compared to EE rats. There was no significant difference between groups in anxiety levels, but I rats were significantly more active. Using a concurrent model, with ET solution and an isochaloric solution as reiforcers, the demand elasticity was accessed by increasingly VRs, first for the isochaloric alternative, then for the ET solution. The introduction of an isochaloric concurrent reiforcer altered ET consumption of I rats, without affecting EE rats consumption. Groups did not differ in demand elasticity for ET, but it was shown that this demand is relatively inelastic while demand for the isochaloric solution is very elastic, especially for I rats, though. I rats consumed more isochaloric solutions than EE rats. Drug abuse and dependency must be understood using the same laws that regulate so called normal behavior, these phenomena do not belong to a special category, and choice models are essential for that understanding.
78

Orientação endógena e exógena da atenção em ratos / Endogenous and exogenous orienting of attention in rats

Cruz, Mateus Torres 09 August 2017 (has links)
Foi investigado o curso temporal da orientação da atenção numa tarefa de orientação encoberta adaptada para ratos. A tarefa envolveu a avaliação do efeito de pistas auditivas centrais e periféricas, preditivas ou não preditivas, sob o tempo de reação a alvos visuais apresentados à direita ou à esquerda do campo visual. Foram utilizados tempos entre pista e alvo (SOAs) entre 50 a 1200 ms. Pistas centrais consistiram em bipes de 5 ou 8 kHz reproduzidos em ambos ouvidos concomitantemente. Neste caso a frequência do bipe indicava o lado para o qual a atenção deveria ser orientada. Pistas periféricas constituíram-se de bipes de 5 ou 8 kHz, apresentados individualmente no ouvido esquerdo ou direito. Neste caso o lado da apresentação do estímulo indicava a direção para a qual o animal deveria orientar a atenção. Esses estímulos foram apresentados de forma preditiva - em 80% das tentativas as pistas indicavam corretamente a localização do alvo (tentativas válidas) e em 20% o indicavam incorretamente (tentativas inválidas) - ou não preditiva - 50% de tentativas válidas e 20% de tentativas inválidas - a depender do grupo. Vinte e quatro ratos Wistar machos, com 3 meses no início dos experimentos, divididos em quatro grupos experimentais independentes - Central Preditivo (CP), Central Não Preditivo (CNP), Periférico Preditivo (PP) e Periférico Não Preditivo (PNP) - foram empregados. Os resultados mostram que animais dos grupos preditivos (CP e PP) respondem mais rapidamente e de forma mais precisa em tentativas válidas do que em tentativas inválidas, ao passo que animais em grupos não preditivos (CNP e PNP) respondem da mesma maneira em tentativas válidas ou inválidas. Esses resultados indicam de estes animais foram capazes de orientar a atenção de forma endógena, de forma análoga a seres humanos, sugerindo que ratos podem ser empregados amplamente como modelo animal na avaliação das orientações endógena e exógena da atenção / Orienting of visual attention was investigated in rats using a 3-hole nose-poke task analogous to the covert attention task for humans. The task involved evaluation of the effects of either central or peripheral auditory cues, presented either predictively or non-predictively on reaction times to a visual target presented either to the left or to the right sides of the visual field; stimuli-onset asynchronies (SOAs) varied from 50 to 1200 ms. Central cues were either 5 or 8 KHz auditory stimuli, released on both ears concomitantly. In this case, the frequency indicated the side to which attention should be oriented to. Peripheral cues were 5 and 8 KHz auditory stimuli presented individually either to the left or to the right ears. In this case, the sound source indicated to which side attention should be oriented to. These stimuli were presented either predictively - 80% of cues predicted the target\'s location correctly (valid trials) and 20% of cues predicted it incorrectly (invalid trials) - or non-predictively - 50% of valid trials and 50% invalid trials - depending on the group. Twenty-four male Wistar rats, 3 month-old at the beginning of the experiment, divided in four independent groups - Central Predictive (CP), Central Non-Predictive (CNP), Peripheral Predictive (PP) and Peripheral Non-Predictive (PNP) - were employed. Animals on predictive groups (CP and PP) showed faster and more accurate responses on valid trials than on invalid trials, while non-predictive groups (CNP and PNP) didn\'t show any differences on reaction times and accuracy in valid as compared to invalid trials. These results indicate that rats do orient attention endogenously, analogously to humans. This suggests that these animals may be employed as animal model to the study of endogenous and exogenous orienting of attention
79

An INNOVATIVE USE of TECHNOLOGY and ASSOCIATIVE LEARNING to ASSESS PRONE MOTOR LEARNING and DESIGN INTERVENTIONS to ENHANCE MOTOR DEVELOPMENT in INFANTS

Tripathi, Tanya 01 January 2018 (has links)
Since the introduction of the American Academy of Pediatrics Back to Sleep Campaign infants have not met the recommendation to “incorporate supervised, awake “prone play” in their infant’s daily routine to support motor development and minimize the risk of plagiocephaly”. Interventions are needed to increase infants’ tolerance for prone position and prone playtime to reduce the risk of plagiocephaly and motor delays. Associative learning is the ability to understand causal relationship between events. Operant conditioning is a form of associative learning that occurs by associating a behavior with positive or negative consequences. Operant conditions has been utilized to encourage behaviors such as kicking, reaching and sucking in infants by associating these behaviors with positive reinforcement. This dissertation is a compilation of three papers that each represent a study used to investigate a potential play based interventions to encourage prone motor skills in infants. The first paper describes a series of experiment used to develop the Prone Play Activity Center (PPAC) and experimental protocols used in the other studies. The purpose of the second study was to determine the feasibility of a clinical trial comparing usual care (low tech) to a high-tech intervention based on the principles of operant conditioning to increase tolerance for prone and improve prone motor skills. Ten infants participated in the study where parents of infants in the high tech intervention group (n=5) used the PPAC for 3 weeks to practice prone play. Findings from this study suggested the proposed intervention is feasible with some modifications for a future large-scale clinical trial. The purpose of the third study evaluated the ability of 3-6 months old infants to demonstrate AL in prone and remember the association learned a day later. Findings from this study suggested that a majority of infants demonstrated AL in prone with poor retention of the association, 24 hours later. Taken together these 3 papers provide preliminary evidence that a clinical trial of an intervention is feasible and that associative learning could be used to reinforce specific prone motor behaviors in the majority of infants.
80

Operant Conditioning of Tibialis Anterior and Soleus H-reflex Improves Spinal Reflex Modulation and Walking Function in Individuals with Motor-Incomplete Spinal Cord Injury

Manella, Kathleen J 05 December 2011 (has links)
Spinal cord injury (SCI) manifests signs of spasticity, plantar flexor (PF) hyperreflexia and ankle clonus, and deficits in motor function. In individuals with motor-incomplete SCI (MISCI), ankle clonus may limit independent walking function. Ankle clonus is attributed to enhanced soleus stretch reflex (SSR) excitability due to decreased supraspinal input and maladaptive reorganization of spinal reflex circuitry. We explored these questions: 1. What are the biomechanical, clinical, and neurophysiologic correlates of ankle clonus? 2. Does locomotor training improve ankle clonus and walking function? 3. Will operant conditioning-based interventions that increase tibialis anterior activation or decrease soleus reflex excitability improve ankle motor control and walking function? In Chapter 2 we compared Ankle Clonus Drop Test (Drop Test) measures with clinical and neurophysiologic measures. Drop Test measures were highly reliable and exhibited moderate to strong correlations with clinical and neurophysiologic measures. Analysis of EMG activity during clonus revealed a predominant pattern of antagonist coactivation. In Chapter 3 we investigated the effects of locomotor training on PF and quadriceps spasticity, and walking function. We assessed responsiveness of the PF reflex threshold angle, a Drop Test measure of PF spasticity. PF and quadriceps spasticity decreased after locomotor training and were moderately correlated with increased walking speed. The PF reflex threshold angle measure discriminated between individuals with and without clonus. In Chapter 4 we compared the effects of two operant-conditioning based interventions to, (1) increase TA EMG activation (TA↑) and (2) decrease SOL H-reflex amplitude during active dorsiflexion (SOL↓), on reflex modulation, ankle motor control, and walking function. Each intervention improved walking function; however, modulated the variables in unique ways. TA↑ improved deficits of strength and range of motion, and SOL↓ improved modulation of SSR and SOL/TA coactivation. In Chapter 5 we discussed implications of our conclusions: (1) Drop Test ankle clonus measures are valid, reliable, and responsive; (2) antagonist coactivation was predominant during ankle clonus; (3) in individuals with chronic MISCI, locomotor training decreased PF and quadriceps spasticity and improved walking function; and (4) an operant conditioning-based intervention to either increase TA strength or decrease SOL reflex excitability improved spinal reflex modulation and walking function.

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