Matching Items (398)
ContributorsWard, Geoffrey Harris (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-18
Description
Smoking remains the leading cause of preventable death in the United States, and early initiation is associated with greater difficulty quitting. Among adolescent smokers, those with attention-deficit hyperactivity disorder (ADHD), characterized by difficulties associated with impulsivity, hyperactivity, and inattention, smoke at nearly twice the rate of their peers. Although cigarette smoking is highly addictive, nicotine is a relatively weak primary reinforcer, spurring research on other potential targets that may maintain smoking, including the potential benefits of nicotine on attention, inhibition, and reinforcer efficacy. The present study employs the most prevalent rodent model of ADHD, the spontaneously hypertensive rat (SHR) and its control comparison Wistar Kyoto (WKY) to examine the effects of acute and chronic subcutaneous nicotine injections on performance in three operant response inhibition paradigms. Functional activation in select regions of the prefrontal cortex and striatum was also explored. Acute (0.1, 0.3, 0.6 mg/kg) and chronic (0.3 mg/kg) nicotine increased impulsive responding regardless of strain, dose, or operant schedule. Dose-dependent decreases in latency to initiate the task were also observed. SHR receiving daily nicotine injections showed less activation in the nucleus accumbens shell compared to saline controls. Despite close similarities, one of the three operant tasks did not detect response inhibition deficits in SHR relative to WKY. A closer examination of these tasks may highlight critical components involved in the amelioration of response inhibition deficits.
ContributorsMazur, Gabriel Joseph (Author) / Sanabria, Federico (Thesis advisor) / Killeen, Peter R (Committee member) / Neisewander, Janet L (Committee member) / Wynne, Clive DL (Committee member) / Arizona State University (Publisher)
Created2014
Description
Research in the area of childhood trauma has shown a substantial amount of psychological maladjustment following the experience of traumatic events in childhood. Trauma survivors are at risk for developing a multitude of adverse psychological outcomes as well as unsafe behaviors following the event of trauma. One unifying theme within these psychological sequelae is the nature of impulsive behaviors. Delay-discounting refers to the subjective decrease in value of a reward when its presentation is delayed. Delay-discounting is often used as an index of impulsive behavior. This study poses two primary questions: 1) Can childhood trauma predict rates of delay-discounting? 2) Could delay-discounting predict psychological maladjustment for individuals who have experienced childhood trauma? This study will seek to answer these questions using an online version of the Kirby et al., 1999 hypothetical delay-discounting method, as well as the Barratt Impulsiveness Scale (BIS-11), to measure trait impulsivity. Measures of depression (BDI-II), life events (LEC), post-traumatic stress (PCL-C), and drug and alcohol abuse (DAST-20) will also be included. Participants included a sample of university students ages 18-52 (n=521, females = 386, males = 135) with a mean age of 25.19 years. Results indicated that childhood trauma was not a significant predictor of delay-discounting rate, nor was delay-discounting rate a significant predictor of psychological maladjustment. Limitations and future directions are discussed.
ContributorsForeman, Emily S (Author) / Robles-Sotelo, Elias (Thesis advisor) / Roberts, Nicole A. (Committee member) / Hall, Deborah L. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Delay discounting is the decline in the present value of a reward with delay to its receipt. (Mazur,1987). The delay discounting task is used to measure delay discounting rate, which requires the participants to choose between two options: one involves immediate delivery of a reward, and other involves delivery after a delay, and the immediate rewards are adjusted in value until the subject feels there is no difference between the immediate and the delayed reward. Some previous studies (Robles and Vargas, 2007; 2008; Robles et al., 2009) found that the order of presentation of the immediate rewards (ascending or descending) significantly influenced the estimated delay discounting rate, which is known as the order effect. Uncertainty about the future and impulsivity could explain delay discounting behavior. The purpose of this study was to explore the order effect in delay discounting assessment. The current study found that the order effect in the delay discounting task can be explained by risk aversion, loss aversion and impulsivity. In the current study, the two kinds of fixed procedure (ascending and descending), and the titrating delay discounting task were used to estimate the degree of delay discounting. Also, two gambling tasks were applied to measure risk and loss aversion indices. The BIS-11 scale was used to assess the level of trait impulsivity. The results indicated that impulsivity biases individuals to choose the immediate small reward rather than the large delayed reward, resulting in lower area under the discounting curve (AUC) when estimated with the ascending-sequence delay discounting task. Also, impulsivity moderated the relationship between loss aversion and AUC estimated with the descending-sequence delay discounting task.
ContributorsLi, Yaqi (Author) / Robles, Elías (Thesis advisor) / Hall, Deborah (Committee member) / Duran, Nicholas (Committee member) / Arizona State University (Publisher)
Created2018
ContributorsBolari, John (Performer) / ASU Library. Music Library (Publisher)
Created2018-10-04
ContributorsOftedahl, Paul (Performer) / ASU Library. Music Library (Publisher)
Created2018-09-29
Description
The estimation of delay discounting rates (k) typically assume that the relative subjective value of a reinforcer declines as a reciprocal function of its delay. Despite the prevalence, estimates of k based on least-squares fits of relative subjective value to the hyperbolic discount function appear to have serious limitations. This curve-fitting method provides curves, which when averaged, may not accurately reflect the individual subjects’ data. The present study used the hyperbolic discounting function to derive a new dependent measure, termed immediacy premium, which is a linear function of delay. By averaging linear rather than reciprocal functions, the averaged data are more representative of individual data, and comparisons between mean data across treatments or samples is more meaningful. Based on data published, the assumptions of least-square based estimates were evaluated for estimation methods based on relative subjective value and immediacy premiums. This analysis yielded mixed support for each method, thus advising for the implementation of both methods when drawing inferences on treatment effects and population differences.
ContributorsBerk, Harli (Author) / Federico, Sanabria (Thesis director) / Samuel, McClure (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
ContributorsMarshall, Kimberly (Performer) / Meszler, Alexander (Performer) / Yatso, Toby (Narrator) / ASU Library. Music Library (Publisher)
Created2018-09-16
Description
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.
ContributorsWatterson, Elizabeth (Author) / Sanabria, Federico (Thesis advisor) / Olive, Foster (Thesis advisor) / Chassin, Laurie (Committee member) / Neisewander, Janet (Committee member) / Arizona State University (Publisher)
Created2015
ContributorsTaylor, Karen Stephens (Performer) / ASU Library. Music Library (Publisher)
Created2018-04-21