Nonsuicidal self-injury (NSSI) is the deliberate destruction of one's own body tissue (e.g., cutting, skin picking, biting, hitting) without conscious suicidal intent. Cognitive and affective difficulties may contribute to the development and maintenance of NSSI, such that emotion regulation may mediate the link between cognitive control difficulties and NSSI in youth. This study examined developmental links between cognitive control and emotion regulation on several facets of self-injurious thoughts and behaviors in a large sample of youth, collected via the ABCD Study (N=6447). Although a mediation of emotion regulation on cognitive control and self-injurious thoughts and behaviors was not supported, important direct effects were found between neural correlates of inhibition (at ages 9-10 years) on NSSI at 11-12 years, and behavioral measures of cognitive flexibility (at 10-11 years) and inhibition (at 9-10 years) on suicidality at 11-12 years. Further, links between poorer cognitive control and poorer emotion regulation were found. An exploratory aim of this study was examining the potential moderating role of autistic traits on significant associations. Although greater autistic traits significantly predicted presence of self-injurious thoughts and behaviors, this study did not find a moderation of autistic traits. These results provide developmental risk markers for NSSI and suicidality in youth. / Doctor of Philosophy / Nonsuicidal self-injury (NSSI) is the direct and intentional harm to one's own body (e.g., cutting, skin picking, biting, hitting) without suicidal intent. One's ability to regulate their cognitions and emotions may explain risk and continuation of NSSI and other suicidal thoughts and behaviors. In specific, one's ability to regulate their emotions may explain the relationship between cognitive control and NSSI in youth. This study examined the relationship between cognitive control and emotion regulation on NSSI and suicidality in a large sample of youth, , collected from the ABCD Study (N=6447). Although emotion regulation did not explain the relationship between cognitive control and NSSI or suicidality, results showed that brain activation when trying to inhibit a response at ages 9-10 related to presence of NSSI at ages 11-12. Additionally, behavior related to one's ability to flexibly shift (at ages 10-11) and inhibit responses (at ages 9-10) related to suicidality at ages 11-12. Links between poorer cognitive control and poorer emotion regulation were also found. Recent work has also found that autistic youth have high rates of NSSI and suicidality, thus, the level of autistic traits on these relationships were evaluated. Although greater autistic traits significantly predicted presence of self-injurious thoughts and behaviors, this study did not find that level of autistic traits impacted links between cognitive control, emotion regulation, and NSSI or suicidality. These results provide developmental risk markers for NSSI and suicidality in youth.

Social Anxiety (SAD) increases in prevalence as children enter adolescence. Adolescents with Autism Spectrum Disorder (ASD) are diagnosed with comorbid SAD at higher rates than these individuals are diagnosed with other clinical disorders, including depression and other anxiety disorders. However, there is little research on whether the presentation and neural underpinning of comorbid SAD within the context of ASD is the same as SAD alone. Individual and diagnostic differences exist in neural and biological mechanisms of fear conditioning. Characterization of whether neural mechanisms of fear are different within ASD with comorbid SAD and SAD alone may better inform clinical treatments. Accordingly, the present study characterizes neural responses during a fear-inducing experiment, as measured by fMRI. Fifty-seven adolescents participated in this study, with adolescents with ASD and SAD (n=17), SAD alone (n=20), and typically developing adolescents (n=20). All participants completed two fear conditioning and reversal paradigms while completing an fMRI scan. The paradigm consisted of a Social condition and Nonsocial condition. An ANOVA for fear conditioning was conducted. Results revealed significant activation in the Inferior Temporal Gyrus (ITG) during fear conditioning. No between group differences were observed, but within-group differences indicated differential modulation of the ITG in the ASD with SAD group in the Social condition compared to the Nonsocial condition. The SAD group demonstrated differential activation between conditioning stimuli in the Nonsocial condition, but not in the Social condition. Results indicate that adolescents with ASD and SAD may display different neural mechanisms for acquiring fear compared to typically developing peers. Results have potential to inform treatment approaches. / Doctor of Philosophy / Based on the 2012 international energy agency (IEA) report, global waste heat energy is estimated to be in the range of 246 Exajoule (1 EJ = 10¹⁸ J). Tapping even small fraction of this wasted energy through thermal energy harvesting techniques will allow us to generate significant magnitude of green energy. Thermoelectrics (TEs) are one of the most promising thermal energy conversion materials as they offer cost-effective and environmentally friendly option with solid-state silent operation and scalability. Among many different options for high temperature TE materials, half-Heusler system is one of the leading candidates as it has the potential to provide high performance and thermal stability at temperatures as high as 873 K. The progress in developing practical half-Heusler materials has been limited for last two decades. Despite many publications, the maximum figure of merit (zT) of n-type half-Heusler materials has been stagnant (zT ~ 1.0). Further, there has been a lack of focus towards module development that can operate under realistic conditions. This dissertation provides comprehensive studies on novel thermoelectric compositions and nanocomposites that are suitable for manufacturing of high temperature modules. Microstructural architectures proposed here provide the ability to tailor electronic transport and phonon scattering beyond the commonly demonstrated regimes. Optimized materials were successfully implemented in efficient and stable thermoelectric generator exhibiting power density on the order of 13.81 W⸱cm⁻² , which is 1400 % higher than that of the fuel cell (~1 W⸱cm⁻² ).

Stereotypes are cognitive heuristics used by all individuals. Researchers studying bigotry have demonstrated that individuals often expose underlying stereotypical racial biases when using less effortful processing (e.g. Correll, Park, Judd, & Wittenbrink, 2002; Miarmi & DeBono, 2007). It is well-established in the resource depletion literature that acting beyond natural impulses requires self-regulation. However, the capacity for self-regulation is limited; prior acts of self-regulation deplete regulatory resources, hence temporarily decreasing the ability to self-regulate. The objective of this study was to examine if resource depletion leads to greater expressions of bigotry. More specifically, self-regulation failure was studied from the emotion resource depletion perspective. Even if resources are depleted however, some individuals may be more motivated than others to suppress their biases. Egalitarianism, a value system that emphasizes equal treatment for all, may be an individual difference that influences this motivation. Thus, egalitarianism was examined as a potential moderator of the resource depletion effect. In the current study, 100 participants were randomly assigned to an emotion suppression or a control condition as they watched a race-relevant social injustice video. Then, participants were given the opportunity to express bigotry through responses to a survey assessing reactions to racial microaggressions. Research findings provide evidence for an emotion resource depletion effect in that individuals suppressing their emotions while watching the video expressed greater bigotry on the survey. Additionally, the results also demonstrated a negative relationship between egalitarianism and expressions of bigotry. Although the interaction effect was not found on the full sample, exploratory gender subgroup analyses suggest that gender is a potential moderator of the interaction between emotion suppression and egalitarianism on expressions of bigotry. Within the male sample, relative to participants scoring low on egalitarianism, high egalitarian participants in the emotional suppression condition showed a greater rate of emotional resource depletion due to the video and in turn showed greater levels of bigotry. In contrast, the evidence was only consistent with an egalitarianism main effect for female participants. Thus, findings from the study demonstrate that aside from cognitive-based depleting tasks, emotion resource depletion can also lead to self-regulation failure in terms of expressions of bigotry. Although the resource depletion effect was robust, there are several limitations in this study that need to be addressed in future research. This includes collecting a more genderbalanced sample so gender can be analyzed as part of a three-way interaction to determine the impact gender had on the model. Furthermore, there was a persisting model misspecification issue; in an ongoing replication study, a measure on agreeableness has been included to assess if this was part of the missing variable problem. Finally, the two self-regulation tasks in the current study were domain-specific in the sense that they were both racially-relevant. Next steps include testing the domain-general argument of the resource depletion effect; that is, if selfregulation failure from emotion suppression would still be observed if the two self-regulation tasks were not related through the context of race. / M.S. / Stereotypes are cognitive heuristics used by all individuals. Researchers studying bigotry have demonstrated that individuals often expose underlying stereotypical racial biases when they rely on more automatic thought-associations as they process situations. It is well-established in research that acting beyond these natural impulses requires self-regulation. For example, one study showed that self-regulation effort was required to suppress the automatic association between African-Americans and negative traits such as hostility and recklessness (Muraven, 2008). However, our capacity to effectively self-regulate is limited; prior acts of self-regulation deplete regulatory resources, hence temporarily decreasing the self-regulation ability. The objective of this study was to examine if resource depletion (i.e. practicing self-regulation and using those regulatory resources) leads to greater expressions of bigotry, and particularly to understand the role of emotions in this process. However, even if resources are depleted, some individuals may be more motivated than others to suppress their biases. Egalitarianism, a value system that emphasizes equal treatment for all, may be an individual difference that influences this motivation. Thus, egalitarianism was examined as a potential moderator of the resource depletion effect. 100 participants were randomly assigned to an emotion suppression or a control condition as they watched a race-relevant social injustice video, then they responded to a survey assessing reactions to racial microaggressions. Research findings demonstrate an emotion resource depletion effect; individuals suppressing their emotions while watching the video expressed greater bigotry on the survey. Additionally, a negative relationship was found between egalitarianism and expressions of bigotry. Interestingly, gender seemed to moderate the interaction between emotion suppression and egalitarianism on expressions of bigotry. For males, relative to low egalitarians, high egalitarians who suppressed their emotions expressed greater levels of bigotry; this indicates a greater rate of emotional resource depletion experienced from watching the video. In contrast, there was no difference in emotion resource depletion in females across egalitarian values. Thus, results demonstrate how emotion resource depletion can lead to expressions of bigotry. This carries implications to our social interactions, as both emotion regulation and interracial encounters are common components of our daily lives.

Cognitive reappraisal (CR) involves changing one’s mental states in response to an emotionally eliciting event in order to down regulate the potential emotional impact. In this study, 50 children who were 9-10 years old were instructed to engage in CR during a sad film. Children were then exposed to a disappointing situation and asked to self-report on their CR after the disappointment task. As hypothesized, there was variability in level of CR use during the disappointment task. Contrary to hypothesis, children’s CR was not related to parent CR. Nor was the association between parent CR and child CR moderated by child baseline frontal EEG asymmetry, as hypothesized. Post-hoc analyses revealed that parent CR moderated the association between child baseline frontal EEG asymmetry and task-related frontal EEG asymmetry, such that children presenting with left frontal asymmetry at baseline and who had parents with higher CR showed left frontal asymmetry during the disappointment task. This was conceptualized as physiological regulation during an emotion event. Post-hoc analyses also revealed that children’s CR after the disappointment task was predicted by task-related frontal EEG asymmetry, as well as self-reports of ER strategies. I conclude that task-specific CR can be assessed in preadolescents but that much research is needed to determine the correlates of child use of CR during emotional situations. / M.S. / Changing the way one thinks of an emotional event is considered highly adaptive, this strategy is referred to as cognitive reappraisal (CR). 50 children between the ages of 9 and 10 and their parents participated in this study. Children were asked to engage in CR while watching a sad film. Then, they were exposed to a disappointing event. After the disappointment, children were asked to complete a self-report questionnaire which gathered information on their CR during the disappointment task. Parents also completed an adult version of this questionnaire. Children’s responses were varied, but their CR was not related to their parent’s CR. Children’s brain activity was also not related to either parent’s nor children’s CR. Parent’s own CR was linked to children’s brain activity during rest and during the disappointment task, making brain activity more extreme for children with greater activation in the frontal left hemisphere of the brain during rest, the area involved with greater regulation. Additionally, children’s CR was predicted by their self-reported emotion regulation and their brain activity during the disappointment task. Our results indicate that wen parents are capable of changing the way they think about an emotional event, using CR, their children are benefitting in ways that are not easily observable, such as through brain activity.

Anxiety disorders are among the most common psychological disorders in childhood<br />with reported rates as high as 41.2% (Cartwright-Hatton, McNicol, & Doubleday, 2006; Cooley,<br />Boyd, & Grados, 2004). A majority of the anxiety intervention programs target children who are<br />7 years of age and older. Yet, many anxiety disorders develop in the preschool years (APA,<br />2000). Therefore, it seems desirable to work with young children who display early signs of<br />anxiety to provide them with skills that would protect them from later full-blown<br />psychopathology. Early intervention and prevention programs may be effective ways to modify<br />the developmental trajectory of anxiety disorders.<br /><br />The present research reports findings from an anxiety prevention program for 4-7 year<br />olds. One hundred and ten children from two schools in a rural part of Southwest Virginia<br />participated. Fifty-seven children from one school received a classroom-based prevention<br />program on a weekly basis over 20 weeks. Fifty-three children from a second school served as a control group. The mean age of the sample was 5.11 years. Results suggested that anxiety was  positively correlated with emotional symptoms (r = .67, p<.001), peer difficulties (r = .21,p<.05), and total difficulties (r =.29, p<.03) on the Strengths and Difficulties Questionnaire for all children. Overall, there were significant decreases in anxiety symptoms from pre to follow-up for both groups of children [F (1, 105) = 7.79, p =.006]. Unexpectedly, anxiety symptoms increased from pre to post for children in the intervention school whereas they decreased for children in the control school. Although these findings are reversed of what was expected, these results may have important implications concerning the importance of providing anxiety education and awareness for teachers. Implications of the current findings, limitations of the study, and directions for future research and dissemination are discussed. / Ph. D.

The role of children’s emotion regulation as a potential mediator or moderator in the relations between a family’s emotional expressiveness and their child’s social anxiety was explored in a sample of clinic-referred children. For the mediational analyses, it was predicted that emotional expressivity in families would be associated with social anxiety and that this relationship would be mediated by emotion regulation. For the moderator analyses, it was predicted that the level of emotion regulation would affect the strength of the relationship between emotional expressivity in families and social anxiety. The hypotheses were explored through hierarchical regression analyses. Family expressivity was marginally related to social anxiety. However, exploratory analyses indicated that emotion regulation failed to mediate or moderate this marginal relationship. Interestingly, mother reports of expressivity were related negatively to social anxiety whereas father reports of expressivity were related positively to social anxiety in their offspring. These findings are discussed and their implications are explored. / Master of Science

Emerging adulthood is a developmental period associated with increased engagement in health risk behaviors, particularly in college students with attention-deficit/hyperactivity disorder (ADHD), a disorder characterized by low distress tolerance and significant difficulty managing emotions. However, research has not examined how these factors impact propensity to engage in health risk behaviors in college students with ADHD. Thus, this study examined the independent and joint effects of ADHD status, emotion regulation, and distress tolerance on the propensity of college students to engage in health risk behaviors (alcohol use, impulsive eating, and drug behaviors). Participants included 143 undergraduate students (81.8% female; 44.1% with ADHD) who completed an online questionnaire via REDCap. Individuals with ADHD reported significantly higher use of maladaptive emotion regulation strategies and lower levels of distress tolerance than the comparison sample. Moderation models using the PROCESS macro for SPSS examined whether the associations between emotion regulation abilities and distress tolerance with health risk behavior engagement were moderated by ADHD diagnostic history. The relation between distress tolerance and engagement in drug use behaviors was moderated by ADHD status, such that for individuals with ADHD, poorer distress tolerance was associated with more drug use. ADHD status also moderated the association between maladaptive emotion regulation strategies and cognitive restraint in eating. For individuals without ADHD, more maladaptive emotion regulation was marginally predictive of less engagement in cognitive restraint around food, but this relation, was not significantly for college students with ADHD. Findings from this study provide insight into intervention targets for college students with ADHD, ultimately resulting in significantly decreased societal and personal health costs. / M.S. / Emerging adulthood is a developmental period associated with increased engagement in health risk behaviors, particularly in college students with attention-deficit/hyperactivity disorder (ADHD), a disorder characterized by low distress tolerance and significant difficulty managing emotions. However, research has not looked at how these factors impact odds of engaging in health risk behaviors in college students with ADHD. Thus, this study examined the independent and combined effects of ADHD status, emotion regulation, and distress tolerance on the propensity of college students to engage in health risk behaviors (alcohol use, impulsive eating, and drug behaviors). Participants included 143 undergraduate students (81.8% female; 44.1% with ADHD) who completed an online questionnaire via REDCap. Individuals with ADHD reported higher use of maladaptive emotion regulation strategies and decreased ability to tolerate distress than the comparison sample. The relation between distress tolerance and engagement in drug use behaviors was moderated by ADHD status, such that for individuals with ADHD, poorer ability to tolerate distress was associated with more drug use. ADHD status also moderated the association between maladaptive emotion regulation strategies and cognitive restraint in eating. For individuals without ADHD, more maladaptive emotion regulation was slightly predictive of less cognitive restraint around food, but this relation was not significant for college students with ADHD. Findings from this study provide insight into intervention targets for college students with ADHD, ultimately resulting in significantly decreased societal and personal health costs.

Previous research showed that children with Autism Spectrum Disorders (ASD) tend to experience high levels of anxiety and anger. Some of the deficits that children with ASD experience are due their difficulty expressing and understanding their own and others' emotions. Thus, the purpose of this pilot study was to assess the feasibility and efficacy of an intervention to teach young children with high functioning autism (HFASD) to recognize their emotions and use emotion regulation strategies to self-soothe. We implemented a group therapy that emphasized children's understanding and knowledge of emotions and coping strategies related to anger and anxiety. Eleven 5-7 year-old children were randomly assigned to either an experimental or delayed-treatment control group. The Emotion Regulation Checklist, Behavior Monitoring Sheet, What Makes My Child Angry/Anxious Questionnaires, and anger- and anxiety-related emotions vignettes were used to measure children's emotion regulation abilities. Finally, maternal confidence of their own and their child's ability to regulate their emotions were measured by the Self-Confidence Rating Scale. Children in the experimental group demonstrated more knowledge of emotion regulation strategies, had fewer negative emotional responses, and showed lower frequency and intensity ratings of anger and anxiety related episodes after treatment. All mothers reported higher levels of confidence in their own and their child's ability to deal with anger and anxiety related emotions after treatment. These findings suggest that teaching young children with HFASD about emotion regulation strategies to manage anger and anxiety emotional states may increase their knowledge about emotion regulation strategies, and improve their emotion regulation abilities. Training mothers about emotion regulation strategies may increase maternal confidence in their own and their child's ability to deal with emotions related to anger and anxiety. Limitations and implications of this study will be discussed. / Master of Science

This study examines associations of emotion language with emotion understanding and emotion regulation during the preschool years. There is evidence that the way parents talk about emotions with their children promotes children's emotion understanding and regulation (e.g. Bird and Reese, 2006; Laible, 2011). However, there has been little attention paid to associations of these outcomes with children's emotion language. In this study, I examined associations of children's emotion language on their emotion understanding and emotion regulation, and tested whether parents' emotion language was indirectly associated with these outcomes through children's emotion language. One hundred fifty-six 3- to 5-year-old children participated with their primary caregiver. Parent-child dyads engaged in an emotion-laden conversation to measure parent and child emotion language. Children also engaged in the locked box task (Cole et al., 2009; Goldsmith et al., 1993) to measure emotion regulation and completed the Diagnostic Analysis of Nonverbal Accuracy (Nowicki and Duke, 1994) to measure emotion understanding. Results differed for younger preschoolers (36 - 53 months) compared with older preschoolers (54 - 69 months) in regard to emotion regulation. For younger preschoolers, path analyses indicated an indirect effect in which parent emotion talk was associated with less attention shifting during the locked box task. There was also a direct effect in which children's greater use of emotion labels was positively associated with emotion understanding. Results may reflect the rapid emotional development occurring during the preschool years and suggest the importance of early emotion socialization. / Ph. D.

Autism spectrum disorder (ASD) is a group of developmental disabilities characterized by impairments in social interaction and communication and by difficulties in emotion recognition and regulation. There is currently no cure for autism but psychosocial interventions and medical treatments exist. However, very few of them have been trialed on young children and others pose limitations. Strengthening young children's capacity to manage their emotions is important for academic success. Thus it becomes important to design and test the feasibility of an appropriate methodology that can teach emotion regulation to young children (age 3-6 years) with ASD. This thesis addresses the problem by proposing a novel framework that integrates physiology with Cognitive Behavior Theory to enable emotion regulation in the target population by exposing them to real-time stressful situations. The framework uses a feedback loop that measures the participant's physiology, estimates the level of stress being experienced and provides an audio feedback. The feasibility of the individual building blocks of the framework was tested by conducting pilot studies on nine typically developing children (age 3-6 years). The attention capturing capacity of different audio representations was tested, and a stress profile generating system was designed and developed to map the measured physiology of the participant on to a relative stress level. 33 out of 43 instances of audio representations proved to be successful in capturing the participants' attention and the stress profiles were found to be capable of distinguishing between stressed and relaxed state of the participants with an average accuracy of 83%. / Master of Science