<p>The goal of this dissertation is to characterize goal directed proactive behavioral responses to threat as well as reactive responses to threat exposure, and to identify the neural and personality correlates of individual differences in these responses. Three specific studies are reported wherein participants completed a novel shock avoidance paradigm while concurrent measures of behavioral, muscular, and sympathetic autonomic activity were collected; self-report was used to measure mood and trait personality; and blood oxygen-level dependent functional magnetic resonance imaging (BOLD fMRI) was used to measure individual differences in threat-related amygdala reactivity and intrinsic connectivity within the corticolimbic circuit.</p><p>Results from Study 1 demonstrate that during threat exposure, participants exhibit increased avoidance behavior, faster reaction times, and increased muscular and sympathetic activity. Moreover, results demonstrate that two broad patterns characterize individual differences in how participants respond during avoidance: 1) a generalized tendency to exhibit magnified threat responses across domains; and 2) a tendency to respond either with proactive behavioral responses or reactive autonomic responses. Heightened state anxiety during the shock avoidance paradigm, and increased trait anxiety were both associated with the generalized tendency to exhibit magnified threat responses. However, gender moderated the relationship between trait anxiety and generalized increases in threat responses during avoidance, such that only male participants exhibited a positive relationship between these two factors. Study 2 demonstrates that intrinsic connectivity between the dorsomedial prefrontal cortex and centromedial region of the amygdala prospectively predicts whether participants will respond proactively or reactively during active avoidance. Finally, Study 3 provides evidence that responses to threat-related facial expressions within the centromedial region of the amygdala are associated with more reactive and less proactive responses during avoidance. </p><p>These results demonstrate that patterns observed in animal models of avoidance, specifically the competition between proactive and reactive responses to threat cues, extend to human participants. Moreover, our results suggest that while anxious mood during performance and heightened trait anxiety are associated with a generalized facilitation of threat responses across domains, measures of neural circuit function within the corticolimbic system predict whether individuals will exhibit increased proactive or reactive responses during active avoidance. In addition to facilitating the search for the neural processes underlying how the brain responds dynamically to threat, these results have the potential to aide researchers in characterizing the symptoms and neural processes underlying anxiety disorders.</p> / Dissertation

<p> Obesity is a chronic and debilitating medical condition that results from a complex mix of genetic, physiological, psychological, and social factors. Despite a recognized consensus regarding the complexity of obesity, little is known about how various demographic, medical, and cognitive performance variables interact in this population, especially in relation to factors which may contribute to the maintenance of obesity over time. Research has supported that one key aspect of this process is eating in response to psychological rather than physiological cues. Given the increased prevalence of psychopathology, particularly mood disorders, in obese individuals, the question arises as to whether there exists an underlying impairment in emotion recognition. </p><p> The current study sought to examine the associations among demographic and medical variables as well as performance on cognitive tests of memory, attention, executive function, sensory-motor, and verbal skills. Contrary to the hypothesis that BMI would be inversely related to performance on tests of emotion recognition, results indicated that as BMI increases, reaction time to complete these tasks decreases. This finding was noted even after the effects of age, gender, estimated pre-morbid IQ, pre-existing medical conditions, and performance in all neurocognitive domains was removed. In addition, when examined across BMI categories, it was observed that participants with BMIs greater than 40 kg/m2 showed the fastest reaction times. Overall, these findings provide support for contemporary theories of emotion which generally agree that emotions evolved to facilitate adaptation to environmental threat.</p>

<p> The purpose of this qualitative descriptive research study was to delineate the perspectives held by medical experts on the meaning and significance of imagery. Thirteen doctorate-prepared experts, including clinicians, educators, and researchers, were surveyed via email and asked basic demographic information and their responses to five open-ended questions. The questions were designed to elicit the experts' perceptions regarding their definition of imagery; the significance of imagery to health; the role of imagery in the experts' professional practices; and the potential relationships that exist between imagery and psychoneuroimmunology (PNI), and imagery and the learning domains. </p><p> Literature from systems theory provided the conceptual framework for this study and a philosophical approach influenced the research design. The study utilized a manual content analysis to identify themes that best described the experts' perspectives. The following three themes emerged: (a) Imagery is a complex construct comprised of both structural and process components which are interconnected via a complex communication system, which responds, directs, and transmits the flow of information within the individual and also between the individual and the environment. (b) The structural component of imagery is multisensorial, multifaceted, and it influences and is influenced by the learning and health domains resulting in the potential for both positive and adverse effects on health. (c) When imagery's process component is used and directed in a goal-oriented, purposeful, intention-driven way, desired outcomes can be achieved in the psychophysiological domains of health. </p><p> The purpose of seeking the experts' perspectives on the meaning and significance of imagery was to gain a better understanding of imagery's role in influencing health. Expanded perspectives were sought because health-risk behaviors are contributing to the rising prevalence of chronic disease in America, which in turn, supports a costly medical model of disease-management rather than one that promotes health. It was concluded that maximizing positive imagery could not only be a potential mechanism for addressing the issues related to chronic disease, but also an effective way to improve the health of the nation.</p>

Background. Anticholinergic (ACH) medications are among biologically plausible and potentially modifiable risk factors of delirium. But the epidemiological findings on its role in hospitalized elderly patients are conflicting. Objectives. To evaluate the association between use of ACH medications and delirium severity and the potential effect-modification on this association by dementia. Methods. A cohort of 278 medical inpatients aged 65 years and over with diagnosed delirium was prospectively followed up with the Delirium Index (DI) every 2--7 days up to 3 weeks in a primary acute care hospital. Their DI scores were associated with measures of ACH medication exposure in the previous day using the mixed linear regression model adjusting for potential confounders or effect modifiers. Results . A total of 47 potential ACH medications were used in the cohort (mean: 1.4 per patient per day). An increase in daily ACH medication exposure of one such medication was on average associated with a subsequent increase in delirium severity of 0.52 DI points (95% CI: 0.3--0.8) after adjusting for dementia, baseline DI score, length of follow-up and concurrent use of non-ACH medications. Dementia did not modify the association. Sensitivity analyses using alternative definitions of ACH medications or excluding antipsychotics did not change the results. Conclusions. Exposure to ACH medications is independently and specifically associated with a subsequent increase in symptom severity of delirium among elderly medical inpatients.

Social self-preservation theory (SSPT) suggests that when faced with social-evaluative threat, a set of psychological and physiological responses are elicited concurrently (Dickerson, Gruenewald, & Kemeny, 2004; Kemeny, Gruenewald, & Dickerson, 2004). A series of studies examined the applicability of SSPT to the examination of social-evaluative body-related threats. In the first study, interviews were conducted to identify and describe uncomfortable body-related situations, and typical responses to such situations. Findings provided preliminary evidence of the applicability of SSPT to everyday body-related threats of young adult women – the threats, context of those threats, and responses to such threats were consistent with SSPT. The second study examined psychobiological responses to, and recovery from, a social-evaluative body-related threat. Findings from this study showed that the social-evaluative body-related threat elicited a psychobiological response consistent with SSPT; women in the threat group reported higher social physique anxiety and had higher cortisol following the threat. The third study sought to extend the applicability of SSPT to examine the psychobiological responses to, and recovery from, an anticipated social-evaluative body-related threat. In addition, the potential moderating effect of appearance investment on responses to a threat was examined. Findings from this study showed that women in the threat group reported higher shame and social physique anxiety after anticipating a social-evaluative body-related threat than following a quiet rest period for women in the control group. Results also indicated that both groups showed an index of decrease for cortisol, with the control group showing a significantly greater overall decrease than the threat group. Appearance investment did not moderate cortisol responses to a threat. Findings from the third study provide partial support for SSPT’s applicability to the anticipation of a social-evaluative body-related threat. Together findings from all three studies provide converging evidence for the use of SSPT in understanding the psychobiology of body image.

Three tasks based on earlier tests (Brownell et al., 1986; Kaplan et al., 1990; Shammi and Stuss, 1999) were administered to 7 right hemisphere damaged (RHD) patients and 10 age- and education-matched healthy controls to assess whether an impaired overall ability to generate linguistic inferences is a major underlying factor contributing to communicative deficits associated with RHD. These tasks examined discourse comprehension and inference generation associated with three types of communicative contexts (disambiguating ambiguous linguistic information, joke appreciation, and pragmatic inferences related to sarcasm). Contrary to expectations, RHD patients' performance was qualitatively different from controls' only for the task requiring pragmatic inferences; for the remaining linguistic inference tasks, RHD subjects were only quantitatively different. The results suggest that the RHD subjects were specifically impaired in their ability to make inferences regarding communicative intention (CI) and are consistent with a model attributing RHD communication impairments to CI comprehension deficits (Sabbagh, 1999).

A number of studies have indicated that both genetic and environmental factors play significant roles in determining alcohol consumption. Stress is one environmental factor shown to influence the initiation and continuation of heavy drinking. The present study investigates the differences between high risk (HR) and low risk (LR) subjects for the future development of alcoholism, as determined from their family history, in the response of the hypothalamic-pituitary-adrenal (HPA) axis to stress and alcohol. 20 HR and 20 LR male subjects, between 18--25 years old, participated in five separate experimental sessions: (1) a placebo drink; (2) a drink containing 0.5g alcohol/Kg.B.Wt; (3) a placebo drink and 30 minutes later the performance of a stress inducing task; (4) an alcohol containing drink and 30 minutes later the performance of a stress inducing task; and (5) the performance of a stress inducing task and 30 minutes later an alcohol containing drink. The response of the HPA-axis was determined by measuring the changes in the plasma adrenal corticotropic hormone (ACTH) and cortisol contents prior to and for four hours following initiation of the treatment. HR subjects presented a lower stress induced increase of plasma ACTH and cortisol contents and a delayed hormone recovery to basal levels. Alcohol consumption prior to the stress task attenuated the stress induced increase in the plasma hormone contents by both LR and HR subjects, while alcohol consumption after the stress task led to a faster return of the hormone contents to basal levels in the HR subjects. Thus, alcohol alters the response of the HPA axis to stress by both the HR and LR subjects. However, there are differences in both, the response of the HPA-axis to stress, and the influence of alcohol consumption on stress responses, as a function of the family history of alcoholism.

Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1990. / Source: Dissertation Abstracts International, Volume: 51-09, Section: B, page: 4589.

Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1997. / Source: Dissertation Abstracts International, Volume: 58-02, Section: B, page: 0998.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 68-02, Section: A, page: 0757. Adviser: Wendy Heller. Includes bibliographical references (leaves 128-149) Available on microfilm from Pro Quest Information and Learning.