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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.
31

Differential Effects of Concurrent Activities During Self-Control Training with Children with Autism

Pamula, Heather 01 May 2012 (has links)
The present study examined the effects of engagement in both low-preferred and high-preferred concurrent activities during self-control training, and determined the activities' differential effects on participants' tolerance to delayed reinforcement. Three children with autism were given a choice between a small immediate reinforcer and a large delayed reinforcer. During baseline, all three participants consistently selected the smaller reinforcer, and the immediate choice. Two training conditions, including a progressive delay to reinforcement with either a preferred or non-preferred concurrent activity, were first alternately and then simultaneously presented. Two of the three participants reversed response allocation from 100% for the sooner smaller reinforcer to over 90% for the larger later reinforcer, and maintained almost exclusive allocation for the preferred activity. All three participants increased delay tolerance by at least 250% of average natural baseline duration.
32

WAITING FOR MORE CERTAIN AND MORE: A STUDY OF THE RELATIVE EFFECTS OF INCREASING PROBABILITY OF REINFORCEMENT AND MAGNITUDE OF REINFORCEMENT ON WAITING IN AN EXPERIENCE-BASED TASK

Webb, Tara L. 01 May 2013 (has links)
In everyday decision making, people often face decisions with outcomes that differ on multiple dimensions. The tradeoff in preferences between magnitude of reinforcement, delay to reinforcement, and probability of reinforcement is a fundamental concern in the decision making literature. Yet, the relative impacts of probability of reinforcement, delay to reinforcement, and magnitude of reinforcement have not been studied together even though researchers have been advocating for the combined study of these variables for decades. The proposed project was designed to determine the relative impacts of magnitude of reinforcement and probability of reinforcement when they were both increasing over a 10 s delay to maximum charge. A first-person shooter video game was adapted for the study of choice when outcome magnitude and probability of reinforcement were increasing either simultaneously (Experiment 1) or separately (Experiment 2) over a 10 s delay. Experiment 1 showed that participants waited longer to ensure a greater probability of reinforcement than to ensure a greater magnitude of reinforcement. The results of Experiment 2 indicated that probability of reinforcement had a stronger impact on behavior than magnitude of reinforcement when they were increasing separately. These experiments indicated that probability of reinforcement outweighed magnitude of reinforcement by a ratio of approximately 3:1.
33

Examining the relationship between delay discounting and self-reported values

Shannon, Kristy L. 01 August 2016 (has links)
The present study used a delay discounting task and the Valued Living Questionnaire to examine the relationship between delay discounting and self-reported values. Thirty-eight participants completed the study. Participants were asked to make choices between immediate and delayed monetary rewards to determine rates of discounting. An exponential function (R2=0.97) provided a strong fit for discounting scores. On the Valued Living Questionnaire, participants rated on a Likert-type scale of 1-10 both the importance and their action in the previous week toward the following values: Family, marriage, parenting, friends, work, education, recreation, spirituality, community, and physical well-being. A composite valued living scored was calculated and compared to participant discounting rates; results suggest that there was a significant relationship between participant valued living scores and K-values (p<0.01) and participant valued living scores and AUC (p<0.02). The results of this study, while preliminary, are important for beginning to understand how values impact decision making.
34

Effects of Gambling Outcomes on Level of Impulsivity

Decker, Katelyn 01 December 2016 (has links)
AN ABSTRACT OF THE THESIS OF Katelyn Louise Decker, Master of Science Degree in Behavior Analysis and Therapy, presented on April 30, 2015, at Southern Illinois University TITLE: EFFECTS OF GAMBLING OUTCOMES ON LEVEL OF IMPULSIVITY MAJOR PROFESSOR: Dr. Mark R. Dixon The effects of exposure to winning and losing gambling outcomes on levels of impulsivity among non-gamblers were investigated in a within-subjects experimental design with randomization of treatment phases. Participants included 20 non-gamblers (10 male, 10 female), 18 years or older, selected from a sample of 40 volunteers who completed the South Oaks Gambling Screen (Lesieur & Blume, 1987) and received a score of 0, indicating no predictors of potential pathological gambling. Dependent measures of levels of impulsivity were recorded using an abbreviated version of the delayed discounting questionnaire described by Dixon et al. (2003). Derived k-values were calculated by fitting indifference points at each delay to the hyperbolic equation proposed by Mazur (1987) and average k-value was calculated for each participant across delays. Participants were exposed to both winning and losing outcomes by completing 25 trials within a slot-machine task programmed in Microsoft Visual Basic Express Edition 2008 (Maclin, et al., 2006, p. 127-154). Results were subjected to statistical analysis to determine whether a statistically significant, functional relationship existed between increases and decreases in level of impulsivity (k-value) in comparison to baseline. Across all participants, regardless of order of experimental conditions, results indicated a more than 26% decrease (-82.20-3133.33) in level of impulsivity (0-2.1694) following a losing outcome and a more than 24% decrease (-89.95-3300) in level of impulsivity (0-2.1694) following a winning outcome in comparison to baseline (0-2.3056). Results are consistent with the hypothesis that exposure to winning outcomes decrease impulsivity, but inconsistent with the hypothesis that exposure to losing outcomes increase impulsivity. Historical perspectives of pathological gambling, social impacts of gambling disorder, and trait and state-dependent perspectives of impulsivity are discussed. Potential implications for further research using delayed discounting measures are provided, as well as potential limitations of the present study. Keywords: gambling, impulsivity, delayed discounting, slot-machine, outcomes
35

The Effects of a Brief Video-Led Mindfulness Exercise on Momentary Choice Impulsivity

Shaffer, Jordan Lorraine 01 December 2016 (has links)
The present study examined the effects of a brief video-led mindfulness exercise on momentary choice impulsivity as measured by a monetary delay discounting survey. Participants in the experimental group watched a video requiring them to engage in a brief breathing exercise while participants in the control group viewed a video unrelated to the topics at hand. Switch point analyses suggested that the experimental group discounted less steeply following the intervention while the discounting slope of the control group remained relatively unchanged. A t-test comparing the average change in AUC values from pre-test to post-test for both groups revealed a significant difference: t (13.17) = 2.94, p = 0.0114. The experimental group demonstrated greater changes in AUC scores from pretest to posttest (M= 0.1036 ± 0.0328) than the control group (-0.00031 ± 0.01317). Additionally, an F-test was conducted to compare variances between the individual score changes of the experimental group and the control group (p < .05). The results suggest that there was a significant difference between the two groups: F = 5.682, p = 0.0082. The results of this study could have several implications for future research regarding delay discounting and mindfulness as an intervention for impulsivity and suggest that telecommunication may be a viable modality.
36

Impulsivity and Delay Discounting Measures Among Smokers and Non-Smokers

Forst, Kimberly Nora 01 May 2018 (has links)
The purpose of the current study is to measure whether delay discounting and impulsivity will differentiate between smokers and non-smokers. It is important to extend upon previous research to understand the effects of antecedent control of delay discounting and impulsivity. Research on this subject is important in developing effective interventions for impulsive behavior like smoking cigarettes. Two surveys were provided to participants: The Monetary Choice Questionnaire (MCQ-27) and the Barratt Impulsivity Scale (BIS-11). An unpaired t test was used to interpret results. Neither the MCQ-11 nor the BIS-11 had a significant difference. Further analysis was conducted comparing age differences using unpaired and paired t tests. There was significant data to support that self-ratings of impulsive behavior differed with age comparisons in the BIS-11. Smokers (ages 26-28) were more impulsive than non-smokers (ages 22-28), and smokers (ages 20-29) showed no statistical significance when compared to smokers (ages 52-68). The MCQ-27 did not show a significant difference in overt impulsive behavior.
37

Modeling ADHD: Impulsivity, hyperlocomotion, and sensitivity to nicotine in the SHR strain of rat

January 2015 (has links)
abstract: ADHD is a childhood neurobehavioral disorder characterized by inordinate levels of hyperactivity, inattention and impulsivity. The inability to withhold a reinforced response, or response inhibition capacity (RIC), is one aspect of impulsivity associated with ADHD. The first goal of this dissertation was to evaluate the fixed minimum interval (FMI) schedule as a method for assessing RIC. Chapter 2 showed that latencies were substantially more sensitive than FMI-derived estimates of RIC to the effects of pre-feeding and changes in rate and magnitude of reinforcement. Chapter 3 examined the ability of the FMI to discriminate between spontaneously hypertensive rats (SHR), an animal model of ADHD, and Wistar Kyoto (WKY) controls. Results from Chapter 3 showed that RIC was not substantially different between SHR and WKY rats. However, latencies were significantly shorter for SHRs than for WKYs suggesting incentive motivation differed between strains. The second goal of this dissertation was to examine the sensitivity of the SHR to nicotine. ADHD is a risk factor for tobacco dependence. The goal of Chapters 4 and 5 was to determine whether the SHR provided a model of ADHD-related tobacco sensitivity. Chapter 4 examined nicotine's locomotor and rewarding effects in adolescent SHRs using the conditioned place preference (CPP) procedure. SHRs developed CPP to the highest nicotine dose tested and were sensitive to nicotine's locomotor-enhancing properties. WKY controls did not develop CPP to any nicotine dose tested and were not sensitive to nicotine's locomotor properties. However, it is likely that nicotine effects were obscured by a pseudo-conditioning to saline in WKYs. Chapter 5 demonstrated that SHRs were more active than WKYs in the open-field but not in the Rotorat apparatus. Results also showed that SHRs and WKYs were both sensitive to nicotine's locomotor sensitizing effects. However, WKYs were more sensitive than SHRs to nicotine's locomotor suppressing effects. Collectively, results from Chapters 4 and 5 show that SHRs are sensitive to the rewarding and locomotor-enhancing properties of nicotine. However, more research is necessary to confirm that SHRs are a suitable model for studying ADHD-related tobacco use. / Dissertation/Thesis / Doctoral Dissertation Psychology 2015
38

Disordered Eating and Borderline Personality Features in Canadian Adolescents: A Longitudinal Study

Czechowski, Karina 07 January 2020 (has links)
The longitudinal relationship between borderline personality features, disordered eating behaviour, and the role of impulsivity were examined using a sample of 643 Canadian adolescents from the McMaster Teen Study. Participants were assessed annually, beginning in Grade 7 until Grade 12.Using path analysis, the results suggest that higher symptoms of impulsivity increase an adolescent’s risk of engaging in disordered eating behaviour, as well as developing borderline personality features in later years. Results also showed a bidirectional relationship between these variables, whereby borderline personality features and disordered eating influence one another throughout time. As well, disordered eating appeared as an antecedent for borderline personality features. The findings highlight the importance for clinicians to be aware of the high comorbidity of disordered eating, borderline personality features, and impulsivity, and that early interventions that target impulsivity and problematic eating behaviour may mitigate the risk of future borderline personality features. Clinical implications, limitations, and future directions are discussed.
39

Psychopathic and Antisocial Personality Disorder Traits As Predictors of Reactive and Instrumental Aggression

Steadham, Jennifer A. 05 1900 (has links)
Aggression has traditionally been subdivided into two correlated, but distinct, subtypes: reactive and instrumental. Reactive aggression (RA) is considered impulsive, emotionally driven behavior, whereas instrumental aggression (IA) is planned and incentive-motivated. This thesis examines the relationships between RA, IA, psychopathy, and antisocial personality disorder (APD) symptoms in male and female offenders recruited from a jail in north Texas. Contrary to predictions, psychopathic traits did not account for more variance in aggression than did APD symptoms. Impulsivity demonstrated slight incremental validity over psychopathy for RA, and to a lesser degree, IA. the continued utility of the reactive-instrumental distinction and implications for professional practice in relation to the current study are examined. Study limitations and directions for future research are discussed.
40

Involvement of Sigma receptors in the detrimental effects of chronic alcohol exposure

Quadir, Sema G. 28 March 2021 (has links)
Alcohol Use Disorder (AUD) is complex psychiatric disease characterized by increased alcohol intake, inability to control consumption, and a negative emotional state during withdrawal. In particular, one often-ignored feature of this negative state is the emergence of alcoholic-induced pain states, manifesting as both allodynia (when a non-noxious stimulus induces a nociceptive response) and hyperalgesia (when a noxious stimulus produces a heightened nociceptive response). Here, we first present evidence identifying standard chow diet as a factor in determining the amount of ethanol consumed as well as the preference for alcohol in an intermittent access to two bottle choice paradigm in mice. Additionally, while all ethanol experienced mice exhibit allodynia during withdrawal compared to the water drinking controls, the type of chow diet does not appear to affect its severity. We then investigated, using the same mouse model, the role of each of the two known subtypes of Sigma receptors, Sig-1R and Sig-2R, in both heavy alcohol drinking and associated pain states. We found that Sig-1R antagonists and Sig-2R modulators are able to decrease ethanol intake and hyperalgesia. Both excessive alcohol drinking and heightened pain states were found to be common outcomes also of another well-established model of alcohol dependence, the chronic intermittent ethanol vapor exposure (CIE), together with an increase of impulsive action. We, therefore, further investigated the role of Sig-1R in this post-dependent phenotype, and found that CIE increases Sig-1R levels in the prefrontal cortex, specifically in the anterior cingulate cortex (ACC) and the prelimbic cortex (PrL). Notably, knockdown of Sig-1Rs in the ACC via viral approach rescues hyperalgesia, but not allodynia nor impulsive action, suggesting that the ACC may be a critical area for alcohol-induced hyperalgesia, but not allodynia or impulsive action. Altogether, the results of this work give important insights into the role of Sig-1Rs in alcohol addiction, and have the potential to lead to novel pharmacological treatments for AUD. / 2023-03-27T00:00:00Z

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