Browsing by Subject "Reward (Psychology)"

Now showing 1 - 5 of 5
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    Attributional Feedback to Prevent the Erosion of Intrinsic Interest by Rewards
    (1994) Fitz, Erika J.; Robbins, Steven J. (Steven Jay), 1962-
    Previous work (e.g. Deci, 1973) shows that rewards can undermine interest in intrinsically interesting tasks. The present study was designed to inoculate subjects against the effects of rewards by giving prior feedback aimed at strengthening internal attributions of interest. The study consisted of a 24-hour period in which Ss played word games, a 45-minute laboratory session where they were paid to play, and another 24-hour period to play without reward. Subjects who received no feedback before the paid session (controls) showed a significant drop in reported interest compared to Ss who did receive feedback (experimentals). Feedback concentrated on interest, not performance. Challenges to a competence-based model of intrinsic motivation are discussed in an extensive literature review.
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    Molecular Mechanisms Underlying Sexual Experience-Dependent Neuroplasticity of the Nucleus Accumbens after in Syrian Hamsters
    (2016) Sidibe, David; Been, Laura
    This study is an aims to clarify the role of delta fos-b in the reinforcement of sexual behavior in Syrian (Golden) hamsters. We used a one-way ANOVA to compare levels of delta fos-b expression from experienced animals to naïve animals, and males to females. Western blot analysis was used to quantify the amount of protein in both the nucleus accumbens (NAc) and the caudate (CP), a control brain area. We found a significantly greater amount of delta fos-b expression in the NAc in sexually experienced hamsters (both males and females) compared to naïve. In addition, there was no difference between sexually experienced males and females in overall delta fos-b expression in the NAc. Implications and future directions point towards further unraveling the unknown mechanisms of reinforcement of sexual behavior in hamsters through humans.
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    Naturally Motivated Behavior and Neuroplasticity: How Sexual Experience Affects Neural Activation During Sexual Behavior in Female Syrian Hamsters
    (2016) Caron, Madeline F.; Been, Laura
    Naturally motivated behaviors, like sexual behavior, are subject to behavioral plasticity, which can affect neuronal function. The purpose of this study was to investigate the plasticity of sexual behavior and neural circuits related to sexual behavior in female Syrian hamsters. We hypothesized that lordosis latency would decrease and lordosis duration would increase with sexual experience. We also hypothesized that sex experience would increase the activation of the projections from the prefrontal cortex (PFC) to the nucleus accumbens (NAc) during sexual behavior. We tested our hypothesis by ovariectomizing and hormone priming all subjects and giving half of the subjects six weeks of sex experience while the other half remained sexually naïve. All subjects then received an injection of a retrograde tracer into their NAc and a final sexual experience. All subjects were then sacrificed, and their brain tissue was collected and stained using immunohistochemical techniques. Our data did not support our hypotheses about lordosis latency or duration, and we were unable to test our neuroplasticity hypothesis due to unquantifiable staining. Limitations and possible troubleshooting techniques are discussed in the context of directions for future research.
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    Neuroplasticity after Sexual Experience in the Nucleus Accumbens of Syrian hamsters
    (2016) Acabá, Luis; Been, Laura
    Research over the past three decades has demonstrated that many neural changes occur in response to rewarding stimuli and behavior. However, most of this research has focused on the changes that occur following drug use and their role in addiction. Less research has investigated the neural changes in response to everyday rewarding behaviors such as eating, exercising, and sexual behavior, and even less has explored whether these changes differ in male and female brains. The goal of this study was to investigate the changes in brain circuitry that occur in Syrian hamsters after exposure to sexual experiences and to identify any possible sex differences involved. Specifically, levels of delta FosB, a transcription factor that is important for long-term neural plasticity following rewarding experiences, was measured in the Nucleus Accumbens (NAc) as a way to quantify these neural changes. This study also aimed at investigating whether the efficiency with which hamsters mate is improved with experience, as measured by the time the hamsters are actively having sex and the amount of sex-related behaviors they perform. It was expected that sexual experiences would lead to an up-regulation of delta FosB in the NAc, that this up-regulation would not differ between the sexes, and that mating efficiency would improve with experience. The results demonstrated that sexual experience led to higher delta FosB levels in the NAc than controls, and that there were no differences in delta FosB levels between males and females of the same group. This study also found that mating efficiency was not improved with experience. The results obtained in this study suggest that the normal rewarding behavior of sexual experience leads to neuroplastic changes in the NAc of Syrian hamsters and that male and female Syrian hamsters likely have similar neuroplastic changes following sexual experiences. This research has the potential to provide a better understanding of how drugs of abuse take advantage of reward pathways, and eventually lead to better treatments for addiction.
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    The Impact of Sexual Experience On Sexual Behavior and Neural Activation in Female Syrian Hamsters
    (2016) Walsh, Olivia; Been, Laura
    Natural rewards and drug reinforcement cause an increase in frequency in motivated behaviors that are aimed at obtaining different rewards. These changes in behavior are reflecting changes in neurobiology. The majority of past research examining motivated behaviors has focused on investigating how addictive drugs affect the brain’s reward pathway, particularly the prefrontal cortex – nucleus accumbens reward pathway. By understanding how the reward pathway functions to regulate the behaviors it evolved for, researchers may be able to better understand how this pathway is activated under pathological conditions and improve treatment. The present study aims to observe 1) how sex experience changes sex behavior; and 2) how sex experience affects the prefrontal cortex – nucleus accumbens reward pathway in female Syrian hamsters. The first prediction is that there will be a decrease in lordosis times and an increase in lordosis duration times across the repeated sexual experiences. The second prediction is that there will be a significant increase in the activation of neuronal projections in the prefrontal cortex – nucleus accumbens reward pathway in the sexually experienced group. The results showed no statistically significant differences in lordosis latency and duration across the seven sexual experiences. This lack of significance may have been due to an interaction between the male and females during sexual behavior that was not measured for, such as ultrasonic sounds. Due to a lack of quantifiable staining, the second hypothesis was not able to be tested. However, it will be interesting to see if there were still changes in neurobiology even though there were not changes in behaviors. By understanding how these naturally motivated behaviors activate the reward pathway, researchers may be able to better understand the neural causation of pathologies of motivation, such as addiction.