<p>Estradiol modulates the use of spatial navigation strategies in female rats. The presence of circulating estradiol enhances learning on tasks that require the use of a hippocampus-dependent place strategy and impairs learning on tasks that require the use of a dorsal striatum-dependent response strategy. When either strategy may be used successfully, estradiol biases females to use a place strategy. While this behavioral effect has been well-described in the young adult female rat, little is known about the mechanisms in the brain that underlie it or how it changes across age. The experiments in this dissertation examined how age, previous experience, and hormonal condition affect the ability of estradiol to modulate learning during explicit training of place and response tasks, as well as navigation strategy use during ambiguous navigation tasks. Age highly influenced the ability of estradiol to influence strategy use. While female rats could use place and response strategies to navigate by postnatal day (PD) 21, estradiol did not bias them to use a response strategy until PD26, just before puberty. In adulthood, previous navigation experience and estradiol interacted to influence navigation strategy use on a series of experiences to an ambiguous navigation task. And, estradiol impaired learning during explicit response training but did not affect place learning. In middle age, estradiol further impaired response learning but still did not affect place learning. Long-term hormone deprivation, however, was detrimental to acquisition of a place task but did not affect response learning. These experiments also examined the effects of estradiol on activity, plasticity, and reliability of neuronal ensembles in several subregions of the hippocampus and striatum during spatial navigation using cellular and molecular techniques that take advantage of the kinetics of the immediate-early genes c-fos and Arc. Increased activation and plasticity during active exploration across several subregions of the hippocampus and striatum reflected similar inputs to these neural systems and similar effects of exploration. However, estradiol modulated the plasticity and reliability of neuronal ensembles in the hippocampus and striatum specifically during goal-directed spatial navigation. Estradiol increased plasticity in CA1 of all behaviorally-trained rats, but only place strategy users displayed high reliability in this plasticity across training and probe trials on a navigation task. Estradiol prevented increase in plasticity and reliability in the dorsolateral striatum displayed by low estradiol response strategy users. These experiments reveal how several factors, including age, influence estradiol's modulation of spatial navigation strategy use and suggest functional mechanisms by which this modulation occurs.</p> / Dissertation

Thesis (M. Ed.(Educational psychology))-University of Pretoria, 2006. / Includes bibliographical references (leaves 105-114) Available on the Internet via the World Wide Web.

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 87-117). Also available in electronic format on the Internet.

Thesis (M.A.)--University of North Carolina Wilmington, 2008. / Title from PDF title page (viewed September 22, 2008) Includes bibliographical references (p. 63-67)

Thesis (M.A.)--York University, 2005. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 94-132). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11909

<p>This project advocates an urgent role for neurobiological evidence and models in the study of altruism. I argue for two claims: that neurobiological evidence should be used to constrain candidate scientific accounts of altruistic behavior, and that neurobiological techniques can be used to elucidate component mechanisms of altruistic behavior. </p><p>Chapter 1 reviews the historical progression of theories of altruism, and the empirical observations that motivated their development. A distinction is drawn between evolutionary altruism -- any self-sacrificial, fitness-reducing behavior, and psychological altruism -- self-sacrificial behaviors that are caused by psychological states like desire and motivation. Three theories of psychological altruism are described, and it is argued that the crucial difference between these theories is their conceptions of the role of affect in motivation, and how the processes of affect and motivation contribute to psychological altruism.</p><p>Chapter 2 describes dominant theories of motivation and the neurobiological and psychological mechanisms that support motivated behavior. Although the evidence is not conclusive, I argue that our best scientific models and neurobiological evidence support affective models of psychological altruism, and that other models are at best incomplete and possibly implausible in light of neurobiological considerations.</p><p>Chapter 3 introduces mind reading approaches to altruism, which argue that the capacity for altruistic motivations depends upon the capacity to represent the psychological states or circumstances of others. I conclude that altruism requires at a minimum the ability to attribute affective experiences to others. Further, I argue that the representations produced by mind reading processes provide a means for distinguishing between self-regarding and altruistic motivations. In contrast with the dominant philosophical theory of psychological altruism, the mind reading model I propose is compatible with the affective theory of motivation depicted in Chapter 2. My own empirical work is described as an example of how neurobiological techniques can reveal the differential role of neural systems in producing self-regarding and altruistic behavior.</p><p>Chapter 4 departs from the mechanistic approach to altruism discussed in the previous chapters, and presents an overview of how the fields of philosophy, psychology, psychobiology and genetics, have investigated altruism as a stable characteristic or personality trait. Recent technological advances make this a promising approach for investigating the psychological and neurobiological systems supporting altruistic behavior.</p> / Dissertation

abstract: Dysregulated cortisol has been linked to a variety of adverse physical and psychological consequences. Stressors in the childhood family environment can influence cortisol activity throughout development. For example, research has shown that both infants and children of depressed mothers exhibit altered levels of cortisol compared to infants and children of non-depressed mothers. It is unclear, however, whether exposure to maternal depression in childhood and adolescence is related to cortisol activity at later stages of development. The current study examined the longitudinal relation between maternal depressive symptoms during late childhood (9-12 years old) and adolescence (15-19 years old) and cortisol activity in offspring in young adulthood (24- 28 years old) in a sample of 40 young adults and their mothers. Maternal depressive symptoms were prospectively assessed at four time points across the 15 year study. Cortisol samples were collected from young adult offspring at the final time point. Findings revealed that higher levels of maternal depressive symptoms during late childhood were associated with lower total cortisol output in young adulthood. Results suggest that attenuated cortisol levels, which put these young adults at risk for a variety of stress-related physical and psychological illnesses, may be a long-term consequence of exposure to maternal depression,. Depressive symptoms in mothers during their child's adolescence, however, did not relate to cortisol output. These findings suggest a sensitive period in late childhood during which the development of HPA activity may be susceptible to the environmental stressor of maternal depression. / Dissertation/Thesis / M.A. Psychology 2011

BACKGROUND: One of the central determinants of functional outcome in schizophrenia is social cognition (SC). With the wide array of SC domains, factor-analysis provides a powerful tool to identify commonalities amongst their underlying dysfunctions and its neural underpinnings. METHODS: The present study performed exploratory factor analysis (EFA) on 93 patients with early course schizophrenia using eight validated SC subtests. Factors derived from this analysis were then used to investigate their relationships with neurocognitive performance, clinical symptoms, and functional outcome. Moreover, subsequent shape analysis of the amygdala and hippocampus was performed using the MAGeT Brain pipeline to investigate their relationship to the composite scores of SC factors. RESULTS: EFA revealed a 3-factor solution, representing the domains of emotion management, emotion recognition, and theory of mind-social contextual appraisal, together accounting for 63.58% of the variance. Interestingly, only the theory of mind-social context appraisal factor correlated with measures of functional outcome. Addition analysis revealed that higher score on the theory of mind factor is significantly related with higher functional outcome measures and verbal learning performance, as well as with lower negative symptoms. Both emotion management and emotion perception factors indicated significant positive correlations with attention-vigilance while only emotion perception significantly correlated with visual learning and memory. Outward convexity of the right amygdala was identified to be positively correlated with the theory of mind-social context appraisal factor (p<0.05, FDR corrected), while the left and right hippocampus, specifically greater surface area of the dorsal-medial and ventral-lateral aspect of the hippocampus respectively, were positively correlated with higher composite score on theory of mind factor (p<0.05, FDR corrected). CONCLUSION: Our EFA indicates overlap amongst SC subtests which represent three different SC subdomains. Furthermore, shape analysis reveals that displacement and surface area of the amygdala and hippocampus respectively play a role in theory of mind. In the future, the SC factors that we identified, along with their neural correlates, could provide essential diagnostic tools to assess SC functioning in early schizophrenia patients, as well as identify strategies for potential improvement following cognitive remediation therapy.

xiv, 111 p. A print copy of this title is available through the UO Libraries. Search the library catalog for the location and call number. / Sleep studies have rarely explored individual differences in sleep disruption and associated outcomes at early ages. In two studies, this dissertation addresses both of these limitations using actigraphy, an activity-derived assessment of sleep, to increase understanding of negative impacts of sleep on early development. Study 1 investigated sleep disruption in foster children and sleep-related treatment outcomes of the Multidimensional Treatment Foster Care for Preschoolers (MTFC-P) intervention program. Study 2 explored individual differences in the associations among sleep, children's behavior, and neurohormonal activity. Four groups of participants ages 3- to 7-years-old were included in both studies: (1) Regular foster care (RFC; n=15); (2) MTFC-P intervention (TFC; n= 17); (3) Low-income community (LIC; n= 18); and 4. Middle-income community (MIC; n=29). Results of Study 1 indicated greater sleep disruption in foster groups, as evidenced by longer sleep latencies and increased variability of sleep duration, in the TFC group than in community groups. There was also indication of a treatment effect as the TFC group slept longer than RFC and LIC groups and had earlier bedtimes, fell asleep earlier, and spent more time in bed than either community group. LIC children had marginally more active sleep than MIC children, indicating a possible role for socioeconomic status in sleep quality. In Study 2, correlational and causal modeling approaches were used to investigate associations among sleep disruption, problem behaviors, and diurnal cortisol. Influences of foster care placement, gender, and age were also examined as potential individual difference factors. Results of mixed linear autoregressive models indicated that children were more likely to display inattentive/hyperactive behaviors after shortened sleep durations. Furthermore, at lower sleep durations, differences among care groups and genders emerged as children in foster care and males were at heightened risk for inattentive/hyperactive behavior problems. No associations between sleep and disruptive problem behaviors were found and there were few associations with morning and evening cortisol values. Results of these studies are discussed in terms of the effectiveness of the MTFC-P program for addressing sleep problems in foster children. Additionally, clinical implications of the heightened likelihood of inattentive/hyperactive behavior problems after disrupted sleep in some children are discussed. / Adviser: Phil Fisher

x, 73 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The current study measured BOLD brain response using functional magnetic resonance imaging (fMRI) to explore the hypothesis that women with bulimia nervosa have a hyper-responsivity of the mesolimbic reward system. Women with bulimia nervosa and healthy controls (N=24) completed an fMRI paradigm involving anticipated and actual receipt of chocolate milkshake and a tasteless control solution. Women with bulimia nervosa showed less activation than healthy controls in the right anterior insula in response to anticipatory food reward and in the left medial orbitofrontal cortex, right posterior insula, right precentral gyms, and right mid dorsal insula in response to consummatory food reward. Covariates related to bulimia diagnosis accounted for some of these effects, but not all. Results suggest that bulimia nervosa may be related to hypo-functioning of the brain reward system rather than hyper-functioning. Implications for intervention and future research are discussed. / Committee in charge: Jeffrey Measelle, Chairperson, Psychology; Jennifer Ablow, Member, Psychology; Don Tucker, Member, Psychology; Eric Stice, Member, Not from U of 0; William Harbaugh, Outside Member, Economics