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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.
111

Preschool Self-Regulation: A Predictor of School Readiness

Geiger, Romin Emmanuel 01 July 2019 (has links)
Substantial evidence from previous research has supported the idea that greater self-regulation in the form of “cool” self-regulation or executive functioning and “hot” self-regulation or effortful control is associated with higher academic achievement within the preschool years and school readiness in the kindergarten years (Anaya, 2016; Carlson, 2005). However, there are only a few studies that assess the prediction of school readiness through validated cool and hot self-regulation tasks (Carlson, 2005; Krain, Wilson, Arbuckle, Kastellanos, & Wilham, 2006; Rothbart, Ellis, Rueda, & Posner, 2003; Thompson & Giedd, 2000). There also few studies examining to what extent cool and hot-self-regulation tasks predict socio-emotional (Blair, 2002) and academic achievement (Bull & Scherif, 2001), which are aspects of school readiness. The current study examined the validity of hot and cool tasks as measures of school readiness within a preschool sample (n = 86) enrolled in one of two programs: one blended Head Start and one full Head Start program. Adapted hot and cool self-regulation tasks, global observer ratings of hot and cool self-regulation tasks (Preschool Self-Regulation Assessment Assessor Report (PSRA-AR) and the Observation of Child Temperament Scale), Woodcock Johnson subtests (Letter Word, Applied Problems, and Picture Vocabulary), teacher ratings of social competence (Social Competence and Behavioral Evaluation) and emotional competence (Emotion Regulation Checklist) were collected in the fall of the school year. Results indicated that performance on cool tasks of measures cool self-regulation were highly correlated with academic performance and that the Snack Delay task and the PSRA-AR component scores (Attention/Impulse Control and Positive Emotion) of hot self-regulation were correlated with socio-emotional competence. Additionally, there were no age differences for hot self-regulation. Regression analyses suggested that hot self-regulation predicted socio-emotional competence and cool tasks predicted academic achievement. However, conclusions regarding hot self-regulation age differences and predictive validity are limited by the sole use of one hot task within this study and the results do not warrant a conclusion regarding whether hot self-regulation and cool self-regulation are separate self-regulation constructs, given the use of only one hot task.
112

EFFECTS OF SOCIAL INTERACTION ON MORPHINE CONDITIONED PLACE PREFERENCE IN ADOLESCENT MALE RATS

Weiss, Virginia G. 01 January 2018 (has links)
The fact that adolescents commonly initiate drug use in social settings is well established. Both clinical and preclinical research has investigated how social interaction is altered by a variety of drugs of abuse. What is less understood is how the rewarding value of drugs of abuse is affected by the presence of social peers. This dissertation aimed to investigate the interaction of morphine and social play on conditioned place preference (CPP) in adolescent male Sprague Dawley rats, using both behavioral and immunohistochemistry (IHC) methods. Rats were exposed to morphine (0, 1, or 3 mg/kg; s.c.), social interaction, or a combination of both and tested in a modified CPP procedure. Behavioral results indicate that, while doses of morphine used produced only weak CPP across experiments, they were sufficient to reduce the rewarding effect of social interaction. IHC results suggest that this finding may be due to reduced activation in NAc shell. Taken together, the results of this dissertation may help to provide an explanation as to why persons with opioid use disorder spend less time interacting with social peers, compared to non-dependent persons.
113

“GOD HATES FAGS”—THE USE OF RELIGION AS JUSTIFICATION FOR PREJUDICE TOWARDS HOMOSEXUALS

Fabros, Michelle S 01 December 2015 (has links)
The Westboro Baptist Church and Phelps family are notorious for their signs proclaiming anti-homosexuality epithets such as “God Hates Fag,” and references to Biblical verses to revile homosexuality (e.g., Romans 1:24-27). Although the homonegativity bias that Westboro patrons and many traditional Christians express is often understood as being rooted in religion, I proposed the possibility that religion can be a justification rather than source of homonegativity. That is, although religion typically is seen as the source of prejudice towards LGBT+ people, I argued that this relationship might work in reverse. I examined under which conditions this “reverse” phenomena might occur in both the Pilot Study and follow-up study. My Pilot Study results suggested that there are differences in participants’ level of Religiosity after falsely being told they held LGBT+ prejudices. These differences were moderated by political alignment. Relatively liberal participants were more likely to have higher levels of Religiosity after receiving Biased Feedback compared to those who received Neutral Feedback. In terms of those who were more politically conservative, their level of Religiosity tended to be about the same regardless of which feedback they received. When it came to Biblical Literalism, however, relatively conservative participants had higher levels of literalism when given the Neutral Feedback compared to relatively liberal participants when given the same Feedback. These findings were mostly replicated in the follow-up Main Study. The results from both studies suggest that, under some circumstances, people might use religion to justify their prejudice towards LGBT+, and the strategy they use is affected by their political alignment (liberal or conservative). There could be differences in motivations between people who are more politically conservative and those who are more politically liberal. These potential differences are addressed in the discussion.
114

Cannabinoid-induced Behavioral Sensitization in Adolescent Sprague-Dawley Rats

Stone, Michelle 01 October 2018 (has links)
Adolescent cannabis use has grown because of increased availability and higher societal acceptance. This increase in cannabis use is problematic as adolescents who experiment with cannabis are more likely to abuse cannabis and experiment with other illicit drugs such as cocaine. The reason for the greater susceptibility to drugs use is unclear and may be the result of altered drug sensitivity after cannabis exposure. Thus, the present investigation used the behavioral sensitization paradigm to examine the behavioral response of early adolescent rats to the cannabinoid agonist CP 55,940 (CP) or cocaine after repeated cannabinoid administration. It was hypothesized that: (1) CP would cause a sensitized response in both male and female adolescent rats, (2) female rats would have a greater behavioral response than male rats, (3) pretreatment with CP would induce cross-sensitization to cocaine, (4) pretreatment with cocaine would cause behavioral sensitization and conditioned activity in male and female adolescent rats. In the first experiment, 137 male and female Sprague-Dawley rats were given CP (4, 13.2, or 40 µg/kg, IP) or vehicle (50% DMSO/H2O) once daily for 5 consecutive days on postnatal day (PD) 30- PD 34. Distance traveled and stereotyped movement was assessed for 1 h after each drug injection. After a 48 h abstinence period (i.e., on PD 36), rats were given CP (4 or 13.2 µg/kg, IP) and distance traveled and stereotyped movement was monitored for 2 h. In the second experiment, 146 male and female rats were tested with the same protocol as in Experiment 1 except that rats were given CP (13.2 or 4 µg/kg), cocaine (20 mg/kg), or vehicle (saline or 50% DMSO/H2O) for five days and then tested with saline or cocaine (10 mg/kg) after 48 h. In the first experiment, no dose of CP altered distance traveled scores or stereotyped movement over the five pre-exposure days nor did CP cause behavioral sensitization on the test day. In the second experiment, pretreatment with cocaine led to enhanced distance traveled scores and stereotyped movement when challenged with cocaine (behavioral sensitization) or saline (conditioned activity) on test day. In contrast, CP-pretreated rats did not show greater activity when injected with cocaine or saline on test day. These data show that cannabinoids do not act like psychostimulant drugs, since CP did not cause the same changes in drug sensitivity as cocaine. The cocaine sensitization observed in adolescent rats indicates that this age group is particularly vulnerable to the rewarding effects of cocaine, and suggests that early cocaine exposure can augment drug seeking behavior. The failure to detect cannabinoid-induced sensitization, conditioned activity, or cocaine cross-sensitization during adolescence suggests that CP, when given at a consistent dose, does not increase the addictive properties of cannabinoids or cocaine. The results also indicate that cannabinoid use does not alter drug responsivity or lead to greater drug seeking and abuse in the adolescent population.
115

AGE-DEPENDENT EFFECTS OF EEDQ ON COCAINE-INDUCED LOCOMOTOR ACTIVITY AND D2 RECEPTOR SUPERSENSITIVITY

Teran, Angie 01 July 2019 (has links)
The neurochemical changes occurring between the preweanling period and adolescence could be crucial for understanding the role development plays in the manifestation of psychotic behaviors. N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) fully attenuates the DA agonist-induced behaviors of adult rats, while potentiating the DA agonist-induced locomotor activity of preweanling rats. My specific hypotheses were as follows: (1) Systemically administered EEDQ would block the cocaine-induced locomotor activity of adult rats. (2) Systemically administered EEDQ would potentiate the cocaine-induced locomotion of preweanling rats. (3) EEDQ would increase the Emax values (a measure of D2 receptor sensitivity) of preweanling rats, but not adolescent or adult rats. And, (4) EEDQ would reduce dorsal striatal β-arrestin-2 (ARRB2) and GRK6 levels (measures of D2 receptor sensitivity) of preweanling rats. Behavioral results were as expected, because EEDQ attenuated the locomotion of adult and adolescent rats, while EEDQ potentiated locomotor activity of preweanling rats. EEDQ enhanced the GTPγS binding of preweanling rats, while depressing ARRB2 levels. These results are consistent with the overarching hypothesis that EEDQ causes DA supersensitivity in preweanling rats. Thus, it is here proposed that EEDQ inactivates a significant number of D2 receptors in preweanling rats, but that the remaining D2 receptors are supersensitive and capable of mediating a potentiated locomotor response.
116

A Social Identity Threat To Merit: The Effects Of Similar Experience On Empathic Concern

McCleary-Gaddy, Asia 01 January 2018 (has links)
Past research indicates that having a similar life experience as another person leads to greater empathic concern towards that person. Two studies empirically investigated if similar experiences of race-based social identity threat can increase the empathic concern of White Americans toward African Americans. Study 1 revealed that White Americans randomly assigned to think about White privilege and then randomly assigned to read a passage about an African American whose accomplishments are attributed to Affirmative Action policies (versus an African American whose accomplishments are attributed to his hard work and merit) felt greater empathic concern toward the African American described in the passage. This effect was significantly mediated by stereotype threat feelings and moderated by group identity. Study 2 revealed that White Americans randomly assigned to think about how others think they have benefited from White privilege and then randomly assigned to read a passage about an African American whose accomplishments are attributed to Affirmative Action policies (versus an African American whose accomplishments are attributed to his hard work and merit) felt greater empathic concern toward the African American described in the passage only when mediated by stereotype threat feelings or stereotype threat cognitions. This mediated effect was moderated by merit identity. This suggests that White American participants do not see the literal similarities between the scenarios of race based social identity threat to merit but can see the similarities in internal feelings and cognitions that both experiences create. Collectively, these studies suggest a novel consideration of social identity and understanding of intergroup processes.
117

Examining the Roles of Sex, Methamphetamine, and Degree of Training in Habit Formation in Rats

Schoenberg, Hannah 01 January 2018 (has links)
Addiction is characterized by a progressive loss of executive control over drug-seeking and consumption, and may be associated with a behavioral shift from instrumental goal-directed actions to stimulus-response habits. Sex differences in drug addiction have been linked to changing hormone levels across the estrous cycle, and females exhibit a particular vulnerability to psychostimulants such as cocaine and amphetamines. Psychostimulants and estrogen both influence dopaminergic activity in the dorsal striatum, a region of the brain in which dopamine activity is thought to mediate the shift from action to habit. In the present set of experiments, we examined the roles of sex, amphetamine, and degree of training on habit formation in rats. To test habit formation in each experiment, animals were trained on a variable interval (VI) schedule of reinforcement to nose-poke for sucrose pellet reinforcers, then the sucrose was devalued in half of the animals by pairing its presentation with injections of lithium chloride (LiCl) to induce nausea. Animals for whom the sucrose was paired with LiCl acquired a conditioned taste aversion for the sucrose reinforcer. When tested in extinction, paired animals who remained goal-directed should inhibit their responding for the devalued sucrose, whereas animals in habit should be insensitive to the devaluation and respond at a similar rate as their non-devalued counterparts. Experiment 1 examined the role of sex in habit formation in which intact male and female rats received identical training, devaluation, and testing in two separate within-sex experiments. After 240 reinforcer exposures females exhibited habitual behavior whereas males remained goal-directed. In Experiment 2, female rats were ovariectomized (OVX) and half were given cyclic estrogen replacement. All animals received either pre-exposure to methamphetamine (METH) or vehicle. Following exposure to 120 reinforcers, a level of training that had previously been shown to be subthreshold to habit formation in males, all female groups demonstrated goal-directed responding at test, revealing a lack of effect of hormone replacement or drug pre-treatment on habit formation in OVX females at this level of reinforcer exposure. Experiment 3 aimed to determine the degree of nose-poke training that would be sub-threshold to habit formation in intact females, and two groups were given different amounts of training. Both groups exhibited habitual responding, indicating that habit threshold in females is lower than hypothesized. Overall, these experiments suggest that females shift into habitual behavior earlier in training than males, and further experiments need to be conducted to determine how factors such as hormone milieu and psychostimulant exposure influence this progression.
118

Examining The Malleability Of Cigarette Product Preference

Davis, Danielle Rose 01 January 2019 (has links)
Introduction: Cigarette preference increases as a function of nicotine content, but preference can be shifted by manipulating cigarette cost. The aim of the present study is to model whether the behavioral-economic metric of unit price (cigarette cost/nicotine content) accounts for cigarette preference shifts and whether preference changes to very low nicotine content cigarettes (VLNCs) are associated with corresponding changes in smoking rate. Methods: 169 daily smokers from populations vulnerable to smoking completed sessions in which choices between smoking normal nicotine content (NNC) (15.8mg/g) and VLNC (0.4mg/g) cigarettes were concurrently available. In Condition 1, choices for both products were available ad-lib at an equal cost of 10 responses/choice. In Condition 2, VLNCs were again available ad-lib at 10 responses/choice, but NNCs were available on a progressive-ratio (PR) schedule wherein response cost (and unit price) increased following each NNC choice (10,160,320…8400 responses/choice). Results were analyzed using ANOVAs and a binomial test (p<.05). Results: Participants preferred NNCs over VLNCs in Condition 1, but shifted preference to VLNCs in Condition 2 (p<.001) immediately before the point in the PR progression where unit price for NNCs exceeded unit price for VLNCs (p<.001). Additionally, this preference shift corresponded with reduced total cigarette consumption compared to Condition 1 levels (p<.001). Conclusions: These results suggest that unit price of nicotine underpins cigarette preference and may provide a metric by which regulators can predict product preference and potentially impact it through policy. These results also demonstrate that VLNCs sustain lower smoking rates than NNCs even under acute laboratory conditions.
119

Biobehavioral Predictors Of Cannabis Use In Adolescence

Spechler, Philip Aaron 01 January 2019 (has links)
Cannabis use initiated during adolescence may precipitate lasting consequences on the brain and behavioral health of the individual. However, research on the risk factors for cannabis use during adolescence has been largely cross-sectional in design. Despite the few prospective studies, even less is known about the neurobiological predictors. This dissertation improves on the extant literature by leveraging a large longitudinal study to uncover the predictors of cannabis use in adolescent samples collected prior to exposure. All data were drawn from the IMAGEN study and contained a large sample of adolescents studied at age 14 (N=2,224), and followed up at age 16 and 19. Participants were richly characterized using psychosocial questionnaires, structural and functional MRI, and genetic measurements. Two hypothesis-driven studies focused on amygdala reactivity and two data-driven studies across the feature domains were completed to characterize cannabis use in adolescence. The first study was cross-sectional and identified bilateral amygdala hyperactivity to angry faces in a sample reporting cannabis use by age 14 (n=70). The second study determined this amygdala effect was predictive of cannabis use by studying a sample of cannabis-naïve participants at age 14 who then used cannabis by age 19 (n=525). A dose-response relationship was observed such that heavy cannabis users exhibited higher amygdala reactivity. Exploratory analyses suggested amygdala reactivity decreased from age 14 to 19 within the cannabis sample, although statistical significance was not found. In the third study, data-driven machine learning analyses predicted cannabis initiation by age 16 separately for males (n=207) and females (n=158) using data from all feature domains. These analyses identified a sparse set of shared psychosocial predictors, whereas the identified brain predictors exhibited sex- and drug-specificity. Additional analyses predicted initiation by age 19 and identified a sparse set of psychosocial predictors for females only (n=145). The final study improved on drug-specificity by performing differential prediction analyses between matched samples of participants who initiated cannabis+binge drinking vs. binge drinking only by age 16 (males n=178; females n=148). A sparse subset of psychosocial predictors identified in the third study was reproduced, and novel brain predictors were identified. Those analyses were unique as they compared two machine learning algorithms, namely regularized logistic regression and random forest analyses. These studies substantiated the use of both hypothesis- and data-driven prediction analyses applied to large longitudinal datasets. They also addressed common issues related to human addiction research by examining sex-differences and drug-specificity. Critically, these studies uncovered predictors of use in samples collected prior to cannabis-exposure. The identified predictors are therefore disentangled from consequences of use. Results from all studies inform etiological mechanisms influencing cannabis use in adolescence. These findings can also be used to stratify risk in vulnerable adolescents and inform targets for interventions designed to curb use.
120

A Field Study Examining the Effect of High Intoxication Levels and Identification Format on Witnesses' Memory for Faces and Events

Altman, Christopher 11 June 2018 (has links)
Members of the legal system (e.g., experts, jurors, investigators) are often skeptical of the information provided by intoxicated witnesses given the negative stigma surrounding alcohol and memory. However, studies examining the relationship between alcohol and witness memory often find that alcohol has no effect on peoples’ recall or their ability to identify a previously seen face. While insightful, the validity of these findings has been questioned given the low-moderate blood alcohol concentration (BAC) levels tested in these predominantly laboratory-based studies, which may not be high enough to consistently expose the cognitive deficits alcohol is expected to create. The present study examined how elevated BAC levels affect witnesses’ recall. In addition, it examined how identification format (i.e., showup versus lineup) impacts witnesses’ identification decisions at elevated BAC levels. Bar patrons (N = 132) were asked to participate in a study examining the effects of alcohol on cognitive and motor functioning. Consenting patrons’ BAC levels were recorded and they were given instructions for their first motor task. Midway through this task a confederate intruder entered the room and caused a disturbance. Participants were then asked to recall the intrusion via a mock interview and identify the intruder from a lineup or showup in which she was pictured (target-present) or was not pictured (target-absent). This procedure yielded participants with BAC levels as high as .24%. Linear regressions showed that elevated BAC levels reduced both the quantity and quality of information provided by participants. Logistic regressions showed that alcohol had no effect on identification decisions, regardless of identification format or target presence. These data highlight the importance of testing witnesses’ memory across a broad BAC spectrum and suggest that the legal system may benefit from expert information on alcohol’s lack of effect on memory for faces, despite what jurors may believe.

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