Theses and Dissertations from UMD
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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 give thesis/dissertation in DRUM
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Item Error Observation in Schizophrenia(2009) Mann-Wrobel, Monica Constance; Blanchard, Jack J.; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Despite the pervasive and impairing nature of social difficulties in schizophrenia, the causes of these problems are not fully understood. It has been suggested that problems with cognitive functioning contribute to the social deficits of schizophrenia. However, little is known about the neural mechanisms that underlie cognitive processes directly linked to social dysfunction in schizophrenia. Recent studies of the mirror neuron system have focused on the error-related negativity (ERN), a negatively-deflected event-related brain potential that is elicited following the commission of an erroneous response. This study examined ERN activity in schizophrenia patients and psychiatrically healthy controls during performance and observation of a confederate performing a computerized flanker task. The lateralized readiness potential (LRP) allowed for a direct comparison of brain activation reflecting response readiness verses error signaling. Correlations between ERN activity during flanker observation, social cognition (i.e., theory of mind), and community social functioning were explored. Finally, correlations between verbal memory, executive functioning, and social functioning were examined and social cognition was explored as a mediator between neurocognition and social functioning. Results indicated that controls produced a robust ERN during execution of the flanker task, whereas ERN activity among patients was comparatively attenuated in amplitude. During observation, there were no significant group differences and no identifiable observation ERN; however, there was greater negative activity following error than correct trials in this condition for all participants. LRP activity did not parallel that of the ERN, supporting the differentiation of motor activity and error-related processing during observation. The only significant correlation to emerge between ERN activity and social cognition and social functioning was between occupational status and execution ERN activity among controls only. Unexpectedly, neurocognition and social functioning were negatively correlated in the patient group. Expectedly, these variables were positively correlated among controls. Therefore, regression analyses were conducted separately by group; however, neither neurocognition nor social cognition predicted a significant proportion of the variance in social functioning. Despite limitations, this research is discussed as a starting point for integrating the study of psychophysiological activity with social behavior and functioning, particularly in a clinical population with pronounced social deficits.Item Brain Electrical Activity in Infants of Depressed and Anxious Mothers(2005-05-09) VanMeenen, Kirsten; Wigfield, Allan; Human Development; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Numerous studies suggest that positive and negative emotions are associated with different patterns of cerebral hemisphere activation and that specific patterns of electroencephalographic (EEG) asymmetry may indicate risk for depression and anxiety. The extant developmental psychopathology literature has examined patterns of EEG asymmetry in the offspring of parents with affective disorders and such research has reported linkages between frontal EEG asymmetry and depression, suggesting that measures of EEG asymmetry may be important neurological markers of risk for affective disorders. Despite the greater prevalence of anxiety disorders than depressive disorders and the literature suggesting that resting EEG asymmetry may serve as an index of both depression and anxiety, no research has yet examined patterns of EEG asymmetry in the offspring of parents with anxiety disorders. The purpose of the present study was to examine early markers of risk for psychopathology in the biological domain (e.g., patterns of EEG asymmetry) in an attempt to elucidate some of the precursors of anxiety and depression in children so that we might gain a better understanding of the development of these disorders. The present investigation examined the relation between maternal history of depression and anxiety and patterns of EEG asymmetry in infant offspring. EEG measures of alpha power (4-6 Hz) in the right and left hemisphere were recorded in infants (four to eight months of age) of mothers with a documented history of major depressive disorder (n = 39), anxiety disorder (n = 22), and comparison subjects (n = 38) during a resting baseline task. Results suggest that maternal depression and maternal anxiety was statistically unrelated to patterns of infant asymmetry. The results suggested that fewer infants of mothers with specific phobia (with and without depression) had right mid-parietal asymmetry than infants of control mothers. Perceived social support was related to patterns of infant EEG asymmetry. These findings provide modest support for the hypothesis that maternal diagnostic history may be related to patterns of infant asymmetry in various regions of the brain during a resting state.Item SUBTYPING BOYS WITH CONDUCT PROBLEMS: CATEGORICAL AND DIMENSIONAL APPROACHES WITH MULIT-MODAL ASSESSMENT OF PSYCHOPHYSIOLOGY AND BEHAVIOR(2004-11-24) Crowley, Michael Joseph; Fox, Nathan A; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examined the physiological and behavioral profile of a group of clinically referred boys (ages 8-12 years) with severe conduct problems. Cerebral EEG asymmetry, fear potentiated startle and cardiac functioning were assessed along with maternal reports of severe antisocial behavior and behavioral measures of reward seeking, reward dominance, and laboratory aggression. Drawing on research seeking to extend the concept of psychopathy to younger populations, this study implemented the Antisocial Process Screening Device (APSD; Frick & Hare, 2001) an assessment instrument designed to assess psychopathic characteristics in children. Two groups of clinically referred children with externalizing problems were screened from an outpatient psychiatry clinic, one with elevated scores on the APSD (> 25) and a second group with externalizing problems but without elevated scores on the APSD (< 20). A third group of comparison boys was recruited from the community. Findings did not support a fear deficit specific to boys with APSD elevations, but rather suggested under some conditions these children may have exaggerated startle reactivity. High APSD boys sought rewards to a greater extent than other clinically referred externalizing boys on a point-subtraction game, but not more than comparison boys. The point-subtraction game did not differentiate groups of boys on aggressive responding. Boys with elevated APSD scores were rated as displaying greater overt and covert antisocial behavior problems than clinically referred boys without high APSD scores. A dimensional perspective was explored as an alternative to the categorical (subtyping) approach. When disruptive behavior disorder measures were treated as continuous dimensions, the APSD was not the criterion most strongly accounted for by predictor variables. Broadband externalizing behavior problems were more strongly associated with indicators of approach motivation and fear reactivity, including resting frontal asymmetry and startle change during threat and safety. Similarly these variables were associated with an oppositional defiant symptom dimension. Regression analyses that focused specifically fear reactivity and insensitivity to punishment for predicting callous-unemotional traits indicated that the door-opening task, startle change during safety and harm avoidance each accounted for unique variance.