301 |
Functional Connectivity of Reward Networks: Characterizing Mechanistic Underpinnings Involved in Positive Affect Deficits within Social Anxiety DisorderCarlton, Corinne N. January 2020 (has links)
Social Anxiety Disorder (SAD) is characterized by excessive concern or fear of negative evaluation in one or more social situations and ranks as one of the most common psychiatric disorders. SAD has also been characterized by significant deficits in social motivation and a lack of reactivity to pleasurable stimuli (i.e., positive affect; [PA]), particularly within social contexts. Recent neuroimaging work has shifted towards examining positively-valenced motivational systems in SAD focused on reward responses to social and nonsocial stimuli. These studies have revealed aberrant reward processing during social reward tasks in individuals with SAD. However, not all individuals with SAD exhibit reward circuitry dysfunction. Therefore, the current study aimed to examine if functional patterns of connectivity in the brain underlie heterogeneity in PA differences in individuals with SAD. Results revealed several functional connectivity strength differences between SAD and control groups within reward regions. Additionally, associations between regions of interest (ROIs)-couplings (i.e., OFC and insula, OFC and subgenual cingulate, insula and cingulate, and cingulate and subgenual cingulate) and diminished PA were present in individuals with SAD, but not controls. Lastly, results demonstrated that individuals with SAD had higher variability in their reward connectivity strength presentations and reports of PA as compared to controls. These results hold significance for the development of interventions for SAD that focus on the enhancement of PA to bolster social reward responsivity. / M.S. / Social Anxiety Disorder (SAD) is a common disorder where individuals experience persistent excessive fear of one or more social situations. Individuals with SAD also tend to show lower social motivation and a lack of reactivity to pleasurable activities/events (referred to broadly as positive affect; [PA]), particularly within social situations. Current work has focused on areas within the brain that are responsible for reward responses, and have indicated that individuals with SAD show different types of reward processing during social reward situations. However, not all individuals with SAD show these same patterns. Therefore, the current study aimed to examine if connections between reward regions in the brain underlie differences in PA differences in individuals with SAD. Results showed several differences between SAD and control groups within reward regions of the brain. Additionally, specific associations between brain regions of interest and low PA were present in individuals with SAD, but not controls. Lastly, results demonstrated that individuals with SAD had higher variability in their connections between reward regions and reports of PA as compared to controls. These results can help inform the development of treatments for SAD that focus on the improving PA in an attempt to increase responsiveness to social rewards.
|
302 |
Mood shapes the impact of reward on perceived fatigue from listeningMcGarrigle, Ronan, Knight, S., Rakusen, L., Mattys, S. 09 January 2024 (has links)
Yes / Knowledge of the underlying mechanisms of effortful listening could help to reduce cases of social withdrawal and mitigate fatigue, especially in older adults. However, the relationship between transient effort and longer-term fatigue is likely to be more complex than originally thought. Here, we manipulated the presence/absence of monetary reward to examine the role of motivation and mood state in governing changes in perceived effort and fatigue from listening. In an online study, 185 participants were randomly assigned to either a ‘reward’ (n = 91) or ‘no-reward’ (n = 94) group and completed a dichotic listening task along with a series of questionnaires assessing changes over time in perceived effort, mood, and fatigue. Effort ratings were higher overall in the reward group, yet fatigue ratings in that group showed a shallower linear increase over time. Mediation analysis revealed an indirect effect of reward on fatigue ratings via perceived mood state; reward induced a more positive mood state which was associated with reduced fatigue. These results suggest that: (a) listening conditions rated as more ‘effortful’ may be less fatiguing if the effort is deemed worthwhile, and (b) alterations to one’s mood state represents a potential mechanism by which fatigue may be elicited during unrewarding listening situations.
|
303 |
Association between Reward Sensitivity and Smoking Status in Major Depressive DisorderFeng, Shengchuang 09 June 2017 (has links)
Chronic nicotine use has been linked to increased sensitivity to nondrug rewards as well as improvement in mood among individuals with depression, and these effects have been hypothesized to be mediated through alternations in striatal dopamine activity. Similarly, chronic nicotine use is hypothesized to influence the mechanisms by which healthy and depressed individuals learn about rewards in their environment. However, the specific behavioral and neural mechanisms by which nicotine influences the learning process is poorly understood. Here, we use a probabilistic learning task, functional magnetic resonance imaging and neurocomputational analyses, to show that chronic smoking is associated with higher reward sensitivity, along with lower learning rate and striatal prediction error signal. Further, we show that these effects do not differ between individuals with and without major depressive disorder (MDD). In addition, a negative correlation between reward sensitivity and striatal prediction error signal was found among smokers, consistent with the suggestion that enhanced tonic dopamine associated with increased reward sensitivity leads to an attenuation of phasic dopamine activity necessary for updating of reward value during learning. / Master of Science
|
304 |
Inferring the Human's Objective in Human Robot InteractionHoegerman, Joshua Thomas 03 May 2024 (has links)
This thesis discusses the use of Bayesian Inference in inferring over the human's objective for Human-Robot Interaction, more specifically, it focuses upon the adaptation of methods to better utilize the information for inferring upon the human's objective for Reward Learning and Communicative Shared Autonomy settings. To accomplish this, we first examine state-of-the-art methods for approaching Bayesian Inverse Reinforcement learning where we explore the strengths and weaknesses of current approaches. After which we explore alternative methods for approaching the problem, borrowing similar approaches to those of the statistics community to apply alternative methods to improve the sampling process over the human's belief. After this, I then move to a discussion on the setting of Shared Autonomy in the presence and absence of communication. These differences are then explored in our method for inferring upon an environment where the human is aware of the robot's intention and how this can be used to dramatically improve the robot's ability to cooperate and infer upon the human's objective. In total, I conclude that the use of these methods to better infer upon the human's objective significantly improves the performance and cohesion between the human and robot agents within these settings. / Master of Science / This thesis discusses the use of various methods to allow robots to better understand human actions so that they can learn and work with those humans. In this work we focus upon two areas of inferring the human's objective: The first is where we work with learning what things the human prioritizes when completing certain tasks to better utilize the information inherent in the environment to best learn those priorities such that a robot can replicate the given task. The second body of work surrounds Shared Autonomy where we work to have the robot better infer what task a human is going to do and thus better allow the robot to assist with this goal through using communicative interfaces to alter the information dynamic the robot uses to infer upon that human intent. Collectively, the work of the thesis works to push that the current inference methods for Human-Robot Interaction can be improved through the further progression of inference to best approximate the human's internal model in a given setting.
|
305 |
Differentiation between the Effects of Physical and Psychosocial Stress on a Feedback-based Learning TaskYang, Xiao 12 July 2017 (has links)
Feedback-based learning is a process in which decisions are made based on the previous feedback. This learning process is influenced by acute stress. However, different laboratory stressors elicit different physiological response patterns, which may influence feedback processing differently. Moreover, individual differences in stress reactivity may be associated with reward sensitivity. Therefore, the present study investigated the effects of psychosocial and physical stress on feedback-based learning. The relationship between stress reactivity and reward sensitivity was also examined. Ninety-two college-aged subjects were assigned into the mental arithmetic (MA) task or the cold pressor task (CPT) group. All subjects performed a feedback-based learning task prior to and after the stressor. Cardiovascular reactions, stress experiences, and learning outcomes were recorded during tasks. Trait differences in behavioral inhibition and activation (BIS/BAS) were also measured. Results indicated different patterns of cardiovascular reactions to the MA and CPT. Learning outcomes were differentially influenced by the MA and CPT. Moreover, subjective stress scores were negatively correlated with the learning rate in the pre-stress learning task. Additionally, BAS Drive subscale score was related to the processing of positive feedback. The results suggested that physical and psychosocial stress influence learning through distinct neural mechanisms and psychological processes. Motivational processes underlie the relationship between stress reactivity and reward sensitivity. This study extended research on stress and learning, and the findings have applied implications in various areas. / Ph. D.
|
306 |
Characterization of Reward Sensitivity, Positive Affect and Working Memory in Socially Anxious Young AdultsGarcia, Katelyn M. 12 October 2021 (has links)
Social anxiety disorder (SAD) is a debilitating disorder marked by persistent fear of one or more social or performance situations that is associated with poor daily functioning in various areas of life. Most empirically-supported interventions for SAD are based on cognitive behavioral models that focus largely on reducing negative emotions. However, these approaches produce only modest rates of remission, suggesting that core components of SAD may not be sufficiently targeted by current treatments. Recent theoretical models have suggested that diminished sensitivity to reward may be a specific factor related to low positive affect (PA) and by extension social anxiety, yet no research has systematically examined this relationship. Additionally, working memory has been found to activate dopamine synthesis related to reward, however this relation has not been demonstrated in social anxiety. Accordingly, research proposed here sought to characterize PA and working memory, and determine whether reward sensitivity is altered in a self-reported socially anxious sample of 59 young adults. We hypothesized that social anxiety symptomatology would be inversely correlated with the magnitude of reward sensitivity as measured using the Reward Bias Task (RBT). Results within the full sample did not support our hypothesis; however, an unexpected relationship between PA and working memory emerged. Once using conservative data quality procedures, results indicated that the online version of the reward bias task demonstrated promising relationships with depression and working memory. Additionally, after controlling for depression, the restricted sample demonstrated a relationship between reward bias mean and working memory, and SPIN and diminished PA. / M.S. / Social anxiety disorder is related to poor daily functioning in various areas of life, such as school, work, and social functioning, and also increases the risk for depression and substance abuse. Over half of patients with the disorder remain symptomatic after treatment. Low levels of positive emotionality, or positive affect (PA), has been associated with social anxiety. Additionally, individuals with social anxiety are thought to have less reward seeking behaviors, which may be related to their working memory abilities. Our study looked at PA, reward and working memory in a sample of 59 socially anxious young adults. Within our full sample, we found that PA and working memory were related, such that participants with higher levels of PA also had better working memory abilities. Within our restricted sample of 17 socially anxious adults we found that reward seeking behaviors were related to depression and working memory. Additionally, after accounting for depression, reward seeking and working memory were related, and social anxiety symptoms and PA were related.
|
307 |
Personal meanings and perceptions of faculty regarding recognition and reward among the three university missionsPortillo, Maria E. Hidalgo de 06 June 2008 (has links)
After the remarkable expansion, and rapid growth of institutions of higher education (IHEs) between 1950 and 1970, campuses started to show signs of financial stress. By 1970, a number of institutions were faced with financial difficulties due to declining resources and steady increases in enrollment (Hansen & Stampen, 1981).
The support that American society and government provided for IHEs earlier this century has decreased, in part due to criticism surrounding management techniques. The general public and state legislators are calling for increased accountability, assessment, graduation rates, and faculty productivity in the three traditional missions of higher education: teaching, research and service.
These external demands have influenced the way work is conducted in all domains of the academy, including the faculty domain. There is little doubt that calls for improved undergraduate education, increased use of technology, a greater focus on applied (versus pure) research, and expanded outreach among others, have affected faculty teaching, research, and service activities. Yet research examining how this activities have shifted in recent years is very limited.
In parallel vein, the recognition and reward system of IHEs (e.g., merit salary increases, teaching load, equipment and facilities) encourage faculty to engage in certain activities that are more valued than other activities.
Traditional reward structures at many institutions have recognized research endeavors at the expense of teaching and service activities. It is reasonable to suggest, therefore, that if IHEs wish to shift attention among teaching, research and service endeavors of faculty, they need to design reward structures to recognize and value the activities they want faculty to undertake. There is very little evidence to suggest that IHEs have adapted their reward structures to promote such changes on the part of faculty.
Therefore, the present study elicits information about faculty perceptions of the way their teaching, research, and service activities have shifted in recent years and how reward structures have or have not been adapted to support these shifts.
The methodology used in this research is semi-structured interviews. Four departments at one university were selected for inclusion in the sample. From each department, ten faculty were randomly selected to participate in the study. The interviews were taped and transcribed to facilitate the analysis of the data.
Conclusions drawn from the study suggest that changes in teaching, research, and service have taken place in recent years. The majority of changes related to the use of technology, followed by changes in class size, teaching style, curriculum reform and the use of teamwork. Faculty perceived that teaching, research, and service activities have changed in recent years in response to internal and external demands, however, the recognition and reward systems have not changed to reflect those changes.
The results of this study suggest that both administrators and faculty may use these data to create new measures of faculty productivity that better reflect changes among the three university missions. The data may also provide other government and private agencies with different ways to assess institutional productivity. / Ph. D.
|
308 |
Reward and drug induced molecular neuroadaptations - the role of circular RNAs and m6A RNA modificationsDabrowski, Konrad, 0000-0002-0545-4576 05 1900 (has links)
The reward system is a network of structures in the brain responsible for the feelings of pleasure, motivation, and decision making. It is comprised of the prefrontal cortex, orbitofrontal cortex (OFC), nucleus accumbens, ventral tegmental area, amygdala and the hippocampus, brain regions that come together to process rewarding stimuli, commonly referred to as rewards, to positively shape behavior. Rewards are well known to induce a range of molecular changes within the reward system that mediate reinforcing effects of rewards—neuroadaptations. These neuroadaptations can not only support adaptive behavior but also can mediate negative symptoms of psychiatric disorders such as anhedonia, withdrawal, or drug tolerance. Hence, aberrant functioning of the reward circuitry is present in patients with psychiatric disorders such as addiction, bipolar disorder, eating disorders, major depressive disorder, and schizophrenia. The molecular mechanisms underlying the function of the reward system are not fully understood and therefore elucidating the reward-induced neuroadaptations could inform future therapeutic approaches for symptoms caused by aberrant reward processing associated with psychiatric disorders. This thesis aims to characterize two types of neuroadaptations, circular RNA (circRNA) transcriptomic changes as well as N6-methyladenosine (m6A) epitranscriptomic adaptations, in the context of appetitive reward and opioids, respectively. First, we focused on describing circRNA related neuroadaptations within the OFC, and their functional implications, in the context of sucrose seeking behavior. We reported the first circRNA profile associated with appetitive reward and identified a regulation of 92 OFC circRNAs by sucrose self-administration. Among these changes we observed a downregulation of circNrxn3, a circRNA originating from neurexin 3 (Nrxn3), a gene involved in synaptogenesis, learning, and memory. Transcriptomic profiling via RNA sequencing and qPCR of the OFC following in vivo knock-down of circNrxn3 revealed differential regulation of genes associated with pathways important for learning and memory and altered splicing of Nrxn3. Furthermore, circNrxn3 knock-down enhanced sucrose self-administration and motivation for sucrose. Using RNA-immunoprecipitation, we reported binding of circNrxn3 to the known Nrxn3 splicing factor SAM68. circNrxn3 is the first reported circRNA capable of regulating reward behavior. In addition, circNrxn3-mediated interactions with SAM68 may impact subsequent downstream processing of RNAs such as the regulation of gene expression and splicing. We then went to characterize m6A epitranscriptomic adaptations induced by a commonly misused drug, the opioid morphine. m6A modifications have not been studied in opioid use disorder, despite being the most common RNA modification. We detected significant regulation of m6A-modifying enzymes in rat primary cortical cultures following morphine treatment, including AlkB Homolog 5 (Alkbh5). The m6a demethylase Alkbh5 functions as an m6A eraser, removing m6A modifications from mRNA. We hypothesized that chronic opioid exposure regulates m6A modifications through modulation of Alkbh5 and profiled m6A modifications in primary cortical cultures following chronic morphine exposure and Alkbh5 knock-down. We observed differential regulation of m6A modifications for 568 transcripts following morphine and 2865 following Alkbh5 knock-down. 103 transcripts were commonly regulated by both morphine and Alkbh5 knock-down, and the two treatments elicited concordant m6A epitranscriptomic profiles, suggesting that a subset of morphine-driven m6A modifications may be mediated through downregulation of Alkbh5 in cortical cultures. Together, this volume expands our understanding of molecular neuroadaptations induced by both appetitive reward and opioids. We have identified potential facilitators that could impact reward seeking, motivation and drug induced molecular adaptations that could inform future studies. / Biology
|
309 |
Customer Perceived Value of Credit Card Rewards : A study on Canadian ConsumersSmedley, Lisa January 2013 (has links)
Abstract Title: Customer Perceived Value of Credit Card Rewards - A study on Canadian Consumers Level: Final assignment for Bachelor’s Degree in Business Administration Author: Lisa Smedley Supervisor: Jonas Kågström Date: 2013 - January Aim: The aim of this study is to investigate what influences Customer Perceived Value; where Canadian consumers’ preferences lie in terms of rewards in the Canadian credit card industry. Method: After researching previous studies and determining what constructs have been utilized prior on similar research topics, I implement a quantitative, and to some extend iterative, research approach. Through survey research, I investigate Canadian consumer preferences through a survey sample of 124 Canadian consumers in Calgary, Alberta, Canada. Result & Conclusions: One finding in the study indicates that utilitarian benefits, which provide financial gain for the card holder, are perceived by respondents as the most valuable reward. Another finding is that inexperienced credit card holders see significantly greater value in symbolic benefits than experienced card holders do. The present study does not support the theory that customer involvement influences the customer’s perception of rewards. 2 Suggestions for future research: More extensive research is needed on the subject of whether Canadian consumers’ perceived value of rewards is influenced by their level of involvement in their credit card. Also, studies involving additional factors that could possibly determine a consumer’s perception of rewards, such as income and ethnicity should be investigated for a more well-rounded understanding of customer preferences. Contribution of the thesis: The present study contributes with new findings that can be of substantial significance for Canadian financial institutions as it provides insight into what credit card rewards Canadian consumers perceive as being valuable to them. Key words: Rewards programs, credit cards, customer loyalty, perceived customer value, timing of reward, type of reward, dimension of benefit, utilitarian, hedonic, symbolic
|
310 |
Belöningssystem och motivation : En fallstudie på Staples / Reward system and motivation : A case study on StaplesModin Svedberg, Lina, Törnkvist, Charlotte January 2018 (has links)
Bakgrund och problem: Ett styrmedel företag kan använda för att nå sina mål är belöningssystem. Utformningen av belöningssystemet samt att det tydligt motiverar de anställda är två viktiga aspekter. Tillsammans är belöningssystem samt motivation två välstuderade ämnen inom vissa branscher. För mer monotona arbeten som lagerverksamhet saknas dock detta arbete. Av denna anledning är det av intresse att studera hur lagerpersonal upplever att de motiveras av belöningssystemet. Syfte: Syftet med studien är att beskriva fallföretagets belöningssystem samt utreda hur de anställda upplever belöningssystemet och huruvida det motiverar dem. Om det empiriska materialet visar på svagheter i belöningssystemet presenteras förslag på förändringar. Metod: Studien har genomförts i form av en fallstudie på fallföretaget. Flertalet respondenter har intervjuats genom semi-strukturerade intervjuer. För att stärka studiens kvalitet har flertalet teoretiska källor använts. Slutsats: Fallföretaget har idag uppsatta mål som de anställda arbetar mot samt ett utvecklat belöningssystem. Det som saknas för att belöningssystemet ska vara en motivationsfaktor är kopplingen mellan uppnådda mål och belöningen för detta.Det empiriska resultatet visar att gemenskapen är det som gjort att de anställda stannat kvar på företaget. Gemenskapen och grundlönen är även de största motivationsfaktorerna. / Background: One of the control mechanisms the companies can use to reach their objectives is a reward system. The parts included in the reward system and that it motivates the employees are two important aspects. The two subjects, reward system and motivation, are very well studied for certain branches. For more monotonous works such as warehouse operations, that is not the case. Therefore,it is interesting to study how warehouse employees experience if and in what way they are motivated by the reward system. Purpose: The purpose of this study is to describe the case company’s reward system but also examine how the employees are experiencing the system and to find out how it motives them. If the empirical data shows that there are weaknesses in the reward system, suggestions for improvements will be given. Method: The paper has been conducted in a case study form. More than one respondent has been interviewed, by semi-structured interviews. To increase the quality of the study different theoretical sources have been used. Conclusions: The employees at the case company are working towards achieving objectives conducted by the company and the company has a well-developed reward system. However, what is missing is the connection between the objectives and the reward to make the reward system a factor of motivation. The empirical data shows that the feeling kinship among the employees is the reason why they have stayed at the company. The kinship and the salary is also the most important factors of motivation.
|
Page generated in 0.0236 seconds