UMD Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/3
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Parental Hostility and Parent Stress Physiology: The Moderating Role of Child Effortful Control(2014) Merwin, Stephanie; Dougherty, Lea R.; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examined the moderating role of child effortful control on the association between observed parental hostility and parents' cortisol awakening response (CAR), a critical index of stress system functioning. Participants included 99 medication-free parents and their preschool-aged children. Parents obtained salivary cortisol samples at waking, 30, and 45 minutes post-waking and at bedtime across two consecutive days. Parental hostility was assessed during an observational parent-child interaction task, and child effortful control was assessed using parent report. Observed parental hostility was associated with parents' lower cortisol levels at 30 and 45 minutes post-waking and lower CAR. Low levels of child effortful control were associated with parents' lower bedtime cortisol. Moreover, results demonstrated an interaction effect between parenting and child behavior on parent CAR. The findings highlight the significance of continued examination of the neurobiology of parenting with a focus on the interactive effects between parenting and child behavior.Item HPA axis reactivity to psychological stress among cocaine dependent individuals(2011) Richards, Jessica Margaret; Lejuez, Carl W; Daughters, Stacey B; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Due to the high prevalence of illicit drug use and subsequent costs to society, researchers have focused on potential mechanisms underlying continued substance use and dependence. One mechanism of interest is the hypothalamic-pituitary-adrenal (HPA) axis and its primary hormone, cortisol. Chronic substance use is associated with elevated basal cortisol concentrations and a blunted cortisol response to stress which has been shown to predict substance use outcomes. However, little is known about the specific conditions under which drug users display a dysregulated cortisol response to stress. Therefore, the current study compared HPA axis response to two different psychological stressors among a sample of cocaine dependent individuals. Results indicated no significant differences in cortisol response across conditions. Future researchers should conduct larger scale studies with carefully matched healthy non-drug using participants to determine whether the absence of a significant stress effect on cortisol functioning is specific to chronic cocaine use.Item FACTORS AFFECTING RATES OF SOCIAL BUFFERING IN JUVENILE RHESUS MACAQUES (Macaca mulatta)(2010) Herman, Khalisa N.; Fox, Nathan A; Human Development; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The purpose of the current study was to investigate genetic and experiential contributions to social buffering between juvenile non human primates. A second aim was to investigate the role of behavioral displays during social buffering, in order to explain social buffering deficits in primates with a history of early social deprivation (Winslow et al., 2003). A total of 31 male rhesus macaques (mean age of 2 years) were videotaped during a Novel Cage Test with and without their homecage partner, and immediately following, blood samples were collected under anesthesia. Subjects were either reared with mothers and peers (mother reared, n=15) or without their mothers in the continuous presence of peers (peer reared, n =16). Cortisol concentrations and rh5-HTTLPR genotypes (long ( l ) and short ( s ) alleles) were generated from blood samples ( l/l =20, l/s =10, and s/s =1), and videos were coded for a variety of stress and affiliation behaviors. Genotype and rearing differences in social buffering of stress behaviors and neuroendocrine function were assessed. Rates of social buffering were also compared between a group of high display subjects that exhibited frequent behavioral displays (n =21) compared to a low display group (n=10). Additionally, the behavioral data were subjected to a lag sequential analysis to examine levels of contingent responsiveness, or the likelihood of behavioral displays occurring before affiliative responses (Bakeman et al., 1997). The results revealed social buffering deficits in the short allele, peer reared, and low display groups. Both the peer reared and low display groups were found to engage in less affiliative behaviors compared to the mother reared and high display groups respectively, while the short allele group appeared to receive less benefit from the presence of a familiar partner. Additionally, contingent responsiveness was identified as a feature of social buffering for the entire sample, but did not explain group differences in social buffering. Taken as a whole, this study identifies genetic and experiential vulnerability factors for social buffering. Furthermore, it adds to our knowledge of how behavioral displays are used during social buffering.