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- All Subjects: Clinical Psychology
Description
Temporal discounting refers to our tendency to discount the value of future rewards. At the extreme, temporal discounting can give rise to detrimental myopic decision-making. Most studies examining the neural basis of temporal discounting in people have been performed using functional Magnetic Resonance Imaging (fMRI). However, fMRI has relatively poor temporal resolution compared with the speed at which people make choices, so understanding choice dynamics using fMRI is difficult. We address the issue utilizing electroencephalography (EEG) to study cortical processes related to temporal discounting. The fMRI literature has found that a network of fronto-parietal brain regions plays an important role during the decision-making process. We aim to explore activity in these regions during the decision process and determine how cortical activity relates to choice parameters. Based on prior fMRI studies, we hypothesized that dorsomedial prefrontal cortex (dmPFC) may act as a regulator of dorsal lateral prefrontal cortex (dlPFC) and there will be an increase in dlPFC activity for more difficult decisions. We also hypothesized that neural activity may be directly related to the temporal discount rate we estimate behaviorally. We utilized regression analysis to determine the relationship. The results found supported our hypotheses. This study may open the door to a better understanding of the dynamic of brain regions while performing a temporal discounting task.
ContributorsTanwisuth, Koranis (Author) / McClure, Samuel (Thesis director) / Brewer, Gene (Committee member) / School of Historical, Philosophical and Religious Studies (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
By providing vignettes with manipulated scientific evidence, this research examined if including more or less scientific detail affected decision-making in regards to the death penalty. Participants were randomly assigned one of the two manipulations (less science and more science) after reading a short scenario introducing the mock capital trial and their role as jury members. Survey respondents were told that a jury had previously found the defendant guilty and they would now deliberate the appropriate punishment. Before being exposed to the manipulation, respondents answered questions pertaining to their prior belief in the death penalty, as well as their level of support of procedural justice and science. These questions provided a baseline to compare to their sentencing decision. Participants were then asked what sentence they would impose \u2014 life in prison or death \u2014 and how the fMRI evidence presented by an expert witness for the defense affected their decision. Both quantitative and qualitative measures were used to identify how the level of scientific detail affected their decision. Our intended predictor variable (level of scientific detail) did not affect juror decision-making. In fact, the qualitative results revealed a variety of interpretations of the scientific evidence used both in favor of death and in favor of life. When looking at what did predict juror decision-making, gender, prior belief in the death penalty, and political ideology all were significant predictors. As in previous literature, the fMRI evidence in our study had mixed results with regards to implementation of the death penalty. This held true in both of our manipulations, showing that despite the level of detail in evidence intended for mitigation, jurors with preconceived notions may still disregard the evidence, and some jurors may even view it is aggravating and thus increase the likelihood of a death sentence for a defendant with such brain abnormalities.
ContributorsBerry, Megan Cheyenne (Author) / Fradella, Hank (Thesis director) / Pardini, Dustin (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Self-control has been shown to predict both health risk and health protective outcomes. Although top-down or “good” self-control is typically examined as a unidimensional construct, research on “poor” self-control suggests that multiple dimensions may be necessary to capture aspects of self-control. The current study sought to create a new brief survey measure of top-down self-control that differentiates between self-control capacity, internal motivation, and external motivation. Items were adapted from the Brief Self-Control Scale (BSCS; Tangney, Baumeister, & Boone, 2004) and were administered through two online surveys to 347 undergraduate students enrolled in introductory psychology courses at Arizona State University. The Self-Control Motivation and Capacity Survey (SCMCS) showed strong evidence of validity and reliability. Exploratory and confirmatory factor analyses supported a 3-factor structure of the scale consistent with the underlying theoretical model. The final 15-item measure demonstrated excellent model fit, chi-square = 89.722 p=.077, CFI = .989, RMSEA = .032, SRMR = .045. Despite several limitations including the cross-sectional nature of most analyses, self-control capacity, internal motivation, and external motivation uniquely related to various self-reported behavioral outcomes, and accounted for additional variance beyond that accounted for by the BSCS. Future studies are needed to establish the stability of multiple dimensions of self-control, and to develop state-like and domain-specific measures of self-control. While more research in this area is needed, the current study demonstrates the importance of studying multiple aspects of top-down self-control, and may ultimately facilitate the tailoring of interventions to the needs of individuals based on unique profiles of self-control capacity and motivation.
ContributorsPapova, Anna (Author) / Corbin, William R. (Thesis advisor) / Karoly, Paul (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2016
Description
There is a robust association between psychosis and cannabis use, but the mechanisms underlying this relation are poorly understood. Because both psychosis and cannabis use have been linked to cardiovascular problems, it is possible that cannabis use exacerbates an underlying vascular vulnerability in individuals prone to psychosis. To investigate microvascular differences in individuals with psychotic symptoms and cannabis use, the current study tested associations between psychotic-like experiences, cannabis use, and retinal vessel diameter in 101 young adults (mean age=19.37 years [SD=1.93]). Retinal venular diameter did not differ between participants with (M=218.08, SD=15.09) and without psychotic-like experiences (M=216.61, SD=16.18) (F(1, 97)=0.01, p=.93) or between cannabis users (M=218.41, SD=14.31) and non-users (M=216.95, SD=16.26) (F(1, 97)=0.37, p=.54). Likewise, mean retinal arteriolar diameter did not differ between participants with (M=157.07, SD=10.96) and without psychotic-like experiences (M=154.88, SD=9.03) (F(1, 97)=0.00, p=.97). However, cannabis users had statistically significantly wider retinal arterioles (M=159.10, SD=9.94) than did non-users (M=154.29, SD=10.20) (F(1, 97)=5.99, p=.016), and this effect was robust to control for covariates. There was no evidence of an interaction between psychotic-like experiences and cannabis use in predicting retinal vessel diameter. These results indicate that cannabis use is associated with microvascular differences in young adulthood. Given current trends toward legalization of recreational cannabis use, future research should explore these differences and their potential consequences for cardiovascular health.
ContributorsHill, Melanie (Author) / Meier, Madeline H (Thesis advisor) / Karoly, Paul (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2016
Description
Adults with autism spectrum disorder (ASD) face heightened risk of co-occurring psychiatric conditions, especially depression and anxiety disorders, which contribute to seven-fold higher suicide rates than the general population. Mindfulness-based stress reduction (MBSR) is an 8-week meditation intervention centered around training continuous redirection of attention toward present moment experience, and has been shown to improve mental health in autistic adults. However, the underlying therapeutic neural mechanisms and whether behavioral and brain changes are mindfulness-specific have yet to be elucidated. In this randomized clinical trial, I utilized functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to characterize fMRI functional activity (Study 1) and connectivity (Study 2) and EEG neurophysiological (Study 3) changes between MBSR and a social support/relaxation education (SE) active control group. Study 1 revealed an MBSR-specific increase in the midcingulate cortex fMRI blood oxygen level dependent signal which was associated with reduced depression. Study 2 identified nonspecific intervention improvements in depression, anxiety, and autistic, and MBSR-specific improvements in the mindfulness trait ‘nonjudgment toward experience’ and in the executive functioning domain of working memory. MBSR-specific decreases in insula-thalamus and frontal pole-posterior cingulate functional connectivity was associated with improvements in anxiety, mindfulness traits, and working memory abilities. Both MBSR and SE groups showed decreased amygdala-sensorimotor and frontal pole-insula connectivity which correlated with reduced depression. Study 3 consisted of an EEG spectral power analysis at high-frequency brainwaves associated with default mode network (DMN) activity. Results showed MBSR-specific and nonspecific decreases in beta- and gamma-band power, with effects being generally more robust in the MBSR group; additionally, MBSR-specific decreases in posterior gamma correlated with anxiolytic effects. Collectively, these studies suggest: 1) social support is sufficient for improvements in depression, anxiety, and autistic traits; 2) MBSR provides additional benefits related to mindfulness traits and working memory; and 3) distinct and shared neural mechanisms of mindfulness training in adults with ASD, implicating the salience and default mode networks and high-frequency neurophysiology. Findings bear relevance to the development of personalized medicine approaches for psychiatric co-morbidity in ASD, provide putative targets for neurostimulation research, and warrant replication and extension using advanced multimodal imaging approaches.
ContributorsPagni, Broc (Author) / Braden, B. Blair (Thesis advisor) / Newbern, Jason (Thesis advisor) / Davis, Mary (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2022
Description
Self-control has been shown to be an important influence behind a variety of risk and protective behaviors, such as substance abuse. Although prior research points to the existence of multiple dimensions of self-control, this concept is not consistently defined and frequently only studied as a conglomerate in clinical research. The current study sought to examine how two experimental manipulations of subcomponents of self-control (motivation and self-efficacy) affect real-world consumptive behavior after accounting for executive function. Additionally, the validity and reliability of a brief state survey measure of perceived self-control capacity, internal motivation, and external motivation was tested. The goal was to examine how basic scientific principles involved in self-control translate into clinically relevant behaviors, which may inform understanding of momentary lapses in self-control behavior, potentially leading to novel prevention and intervention efforts. 94 college students completed a 1-2 hour laboratory protocol during which they completed survey and laboratory-based tasks of self-control and related behaviors, executive function, and ad libitum alcohol consumption. Results showed that the self-efficacy manipulation successfully increased perceived self-control capacity, although this did not lead to a significant reduction in consumption. The motivation manipulation neither increased motivation nor reduced consumption in this sample. However, the brief state survey measure of self-control subcomponents demonstrated strong test-retest reliability and distinction from trait self-control, demonstrating its viability for use in future research. By elucidating the relationships between specific mechanisms of self-control, laboratory-based tasks and manipulations, and real-world consumptive behaviors, prevention and intervention efforts for problems such as alcohol abuse may be tailored to the needs of the individual and made more impactful and cost-effective.
ContributorsPapova, Anna (Author) / Corbin, William R. (Thesis advisor) / Brewer, Gene (Committee member) / Karoly, Paul (Committee member) / McClure, Samuel (Committee member) / Arizona State University (Publisher)
Created2020
Description
The current study explores the extent to which literacy game performance can be used to assess reading comprehension skill and vocabulary knowledge. Standardized reading assessments have the benefit of years of validation across different age groups and reading comprehension levels, allowing teachers to evaluate students’ reading performance and relate it to a national standard. However, these assessments reduce classroom time for learning activities, which may be more authentic indicators of student progress. Students’ reading skills can be measured during learning activities by using game-based stealth assessment of literacy. Game-based assessment may be more enjoyable and less likely to invoke test anxiety than traditional assessments, but enjoyment may also impact the validity of the assessment. The current study recruited participants (n=405) to play five literacy games: CON-Artist, Paraphrase Quest, Fix It, Map Conquest, and Vocab Flash. Students also completed the Gates-MacGinitie Reading Test (GMRT), which serves as a validated measure of reading comprehension skill and vocabulary knowledge. Students answered enjoyment questions after each game and the GMRT, and they completed the Cognitive Test Anxiety questionnaire, which measures trait-level negative thoughts about test-taking. The results indicate that Vocab Flash predicted 31% of variance in reading comprehension and 21% of variance in vocabulary knowledge. The other games were not predictive beyond Vocab Flash, but each of them was weakly correlated with reading comprehension skill and vocabulary knowledge. Three games were more enjoyable than GMRT Reading Comprehension, but no games were more enjoyable than GMRT Vocabulary. Cognitive Test Anxiety was negatively correlated with the GMRT and Vocab Flash, but not with the other games. Game enjoyment moderated the relationship between game performance and reading skill, albeit in differing directions. Paraphrase Quest was less predictive of reading comprehension for students who enjoyed the game, and Vocab Flash was more predictive of reading comprehension for those who enjoyed the game. The findings of this study suggest that a simple vocabulary game can be used to measure reading comprehension skill and vocabulary knowledge. Future research is needed to better understand how game-based assessments can be designed to minimize the effects of test anxiety and enjoyment on performance.
ContributorsChristhilf, Katerina (Author) / McNamara, Danielle S (Thesis advisor) / Roscoe, Rod (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2023