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Are All Relational Judgments the Same? An Investigation of Two Decision Models Using Event-Related Potentials
Year of Dissertation:
Two neurocognitive models of decision-making, Iterative Reprocessing (IR) and Accumulator models have been proposed to explain subjective conceptual and objective perceptual judgments, respectively. To date, there is little evidence from humans in support of the central tenet of both models that there is a direct relation between duration of evaluative processing and judgment difficulty. Further, it is not known if a single model can explain all types of judgments. To compare the timing and location of neural activations underlying decision-making, event-related potentials (ERPs) were recorded while participants completed judgments in a 2-by-2 factorial design with factors of Judgment Type (Objective, Subjective) and Domain (Semantic, Perceptual). To assess the effect of difficulty on evaluative processing, difficulty was manipulated for Objective judgments. Confirming the finding of Johnson and colleagues (2011) both Early and Late LPCs were elicited by all judgments creating an evaluative processing interval. The duration of ERPs reflecting evaluative processing (i.e., accumulation, working memory, selection, monitoring) increased as a function of judgment difficulty for Objective Semantic and Perceptual judgments, providing some of the first direct evidence that duration of this processing is related to difficulty. A comparison of the judgments examined here revealed two networks underlying decision-making; however, these networks did not divide based on judgment type or domain. Instead, judgments differed on whether the details on which the decision was based were analyzed based on global or local properties. The division between networks involve whether judgments can be decided by fitting things together into a whole (e.g., global) (Objective Perceptual, Subjective Perceptual, Subjective Semantic) or can be decided based on only a few details (e.g., local) (Objective Semantic). Processing in the local network is consistent with the IR model, while the global network is consistent with Accumulator models. Results indicate the IR model does not account for explicit subjective conceptual judgments, but can account for Objective Semantic judgments. Further, the study validates that Accumulator models' account for Objective Perceptual judgments and expands this model to both Subjective Perceptual and Semantic judgments, suggesting that these models may provide accurate accounts of most types of decisions that humans make every day.
Electrophysiological Identification of Malingered Executive Dysfunction
Year of Dissertation:
Traditional evaluation of cognitive functioning is based on the assumption that the individual being assessed is responding to the best of his or her abilities. However, when individuals have external incentives to appear more impaired, such as those involved in civil or criminal litigation, the results of these evaluations may be questionable. Therefore, measures designed to assess malingering have become an integral part of many neuropsychological evaluations, particularly in forensic settings. However, these malingering measures have been demonstrated to be vulnerable to both manipulation and coaching. Consequently, recent research has attempted to identify physiological indices of cognitive functioning that are less susceptible to overt manipulation. Previous physiological studies have focused on assessing the validity of an individual's memory impairment, however, this study evaluates the effectiveness of a physiological measure of frontal lobe executive functioning. This study used EEG recording in conjunction with a three stimulus oddball design to compare differences in neural responses in simulated malingerers and controls. The experimental group was tasked with simulating the cognitive deficits associated with traumatic brain injury (TBI). Specifically, the study was designed to compare an event-related potential (ERP) known as the P3a, which is elicited by irrelevant distracter stimuli, and to investigate its resilience to intentional manipulation. The P3a is believed to be an index of frontal lobe executive processes, specifically the attentional orienting response. The results of this study demonstrated that simulated malingerers did not produce a physiological P3a response that was significantly different from control participants. Furthermore, the P3a in simulated malingerers did not demonstrate any of the physiological indicators demonstrated to be present in prior studies with mTBI patients. Not only were malingerers unable to produce a significant change in their basic orienting response, but the very process of attempting to employ additional strategies to appear impaired produced other physiological markers of deceptive responses. Therefore, the P3a component appeared to be unaffected by an individual's motivation or overt performance, thus making it an excellent candidate for measures differentiating between malingerers and patients with genuine TBI. The results are discussed in comparison to traditional behavioral measures of malingered executive deficits, and serve as a pilot study for future development of physiological measures of cognitive functioning that span multiple cognitive domains.
RE-LOCATING RECYCLING: A CONTEXTUAL ANALYSIS OF RECYCLING BEHAVIOR IN THE USA AND GERMANY
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While recycling remains a common research topic within environmentally responsible behavior studies, it is little known how contextual factors such as physical environments, social interactions, and cultural backgrounds influence people's attitudes and behavior. This research adopts an ecological framework and conducts a mixed-method qualitative inquiry of whether and how relocation has impacts on people's ecological thinking and behavior in their everyday life. Semi-structured interviews were conducted within two groups of people: Americans who moved to Munich and Germans who moved to New York City. Interviews were conducted in participants' homes or workplaces. Pictures were taken inside the apartments, in common areas in the buildings, and recycling areas in public spaces to record recycling accessibility. This dissertation describes and analyzes people's recycling behavior in three interrelated aspects. First, it challenges the traditional dichotomous categorization of recyclers versus non-recyclers by presenting a model of recycling orientations in multiple dimensions: material, spatial, and temporal. Second, it investigates various contextual factors including physical, political, and social environments that influence pro-environmental attitudes and recycling behavior. The findings show that different contextual factors are connected to each other and collaboratively influence how people perceive and perform recycling as well as other pro-environmental behavior. Finally, this research examines the effects of relocation and how people change their pro-environmental attitudes and behavior over time. The results demonstrated how changes in physical, social, political, and cultural contexts altered the way people think and act towards the environment. This study explores and confirms the importance of contextual factors in people's recycling attitudinal and behavioral changes and suggests that a consistent and comprehensive environmentally friendly environment is essential to help people build and maintain a greener lifestyle.
Place Connections: A Study of the Dynamics and Planning Process of Remigration in Trinidadians and Tobagonians
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The purpose of this dissertation is to study migration and remigration of Trinidadians and Tobagonians as it relates to the meaning, experiences, and attachment these individuals have with the different places they have lived. The research questions focus specifically on remigrants who have the choice to return to Trinidad and Tobago or not after long-term residence abroad and why they make the decision to return. Interviews and surveys were used to understand the roles of place identity, place attachment, and place dependence in choosing whether or not to remigrate to Trinidad and Tobago. Participants were asked about their understanding of dominant narratives of immigrants and how these narratives do or do not reflect their own perceptions and experiences of an immigrant's life, thus showing the network of social and geographical connections these immigrants form and the value immigrants bring to the host countries. A key finding is that remigration is not solely an economic decision, but instead infused with the meaning of the Place Attachments, Place Identity and Place Dependence created in the home country. People's migration experiences do not tell the whole story about their decision making process for remigrating. The findings suggest that remigration happens because of the social and cultural connections and place attachment individuals maintain through transnationalism.
The geographical imagination of youth: Transformation through political participation and community engagement
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The period of adolescence is strongly associated with explorations of one's identity, values and surroundings. Youth organizations can offer a platform for young people to work collectively on community organizing and campaigns for social justice. Through the process of participating in social conflict and contestation, youth are often engaged in spatial conflict and contestation. The concept of the geographical imagination or critical consciousness about space makes this connection between the social and the spatial explicit. The geographical imagination includes the knowledge and meaning one ascribes to different places, along with an awareness of the social, spatial, political and economic forces that help to produce and maintain these spaces. There is little research that considers the contexts in which the geographical imagination develops in young people and how this relates to their emergent identities as political actors and activists. Interviews, participant observation and a participatory mapping project were conducted over the course of a yearlong case study at a Harlem-based organization. The findings articulate: 1) how young people learn about the social and material aspects of their neighborhood and the world in an `education for liberation' context, 2) how they apply `dimensions' of this spatial lens to trace root causes of issues, analyze the current context and gather perspectives about places, 3) how they enact their geographical imagination using specific `modes' of engaging the environment and 4) the ways in which the goals of social justice youth programs could be furthered by fostering the geographical imagination. This interdisciplinary research clarifies the geographical imagination as a critical construct to analyze the role of space and place in one's biography and as a critical capacity to experience and intervene in the built and natural environment. As young people collectively work to address uneven development, they are learning about the social and spatial relations that affect their lives and taking on new roles as political actors in their community. By extending the concept of the geographical imagination to community engagement, this work contributes to understanding and establishing conditions for young people to not only see things as they are, but how they could be.
MATERNAL MENTALIZATION AND CHILD PSYCHOSOCIAL ADAPTATION FOR CHILDREN WITH LEARNING AND BEHAVIORAL DISORDERS
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This study examined the relationship between maternal reflective functioning (maternal RF) and psychosocial functioning for children with learning and behavioral disorders (LBD). Because many, but not all, children with LBD experience social and emotional difficulties concurrent with learning, language and behavioral impairments, this project aimed to identify within-group differences to highlight protective factors and inform treatment. The study predicted that mothers' capacity to mentalize about their child, the parent-child relationship, themselves as parents, and their child's learning and behavioral disorders (RF-LBD) would be associated with improved psychosocial functioning in their child. The study subjects, 18 mother-son dyads, were part of a larger project, investigating attention in children with language impairments. The child participants were diagnosed with or at risk for Attention-Deficit/Hyperactivity Disorder, a Reading Disorder, or a Language Impairment. The Parent Development Interview was modified for use with parents of learning disabled children to determine maternal RF and RF-LBD. Mothers also completed measures assessing children's social skills, internalizing and externalizing symptoms, and problem behaviors. Results revealed that maternal RF was significantly positively associated with higher social skills in children with LBD. A relationship was not found between maternal RF and measures of children's internalizing and externalizing symptoms and problem behaviors. Moreover, the direction of effects suggested negative, but non-significant correlations between maternal RF and these variables, indicating that mothers with higher RF may actually report higher levels of negative symptoms and behaviors in their LBD children. These results suggest that low RF mothers may not be able to fully attune to and acknowledge their children's more problematic symptoms and behaviors. Significant relationships were not identified between RF-LBD and measures of children's psychosocial functioning implying that a mother's overall mentalizing capacity may have a stronger effect on the developing child, and that RF-LBD is just one aspect of this larger entity. Also, the stress of having a child with an LBD may make it more difficult for the parent to demonstrate stable RF in relation to her child's learning and behavioral problems. These results were discussed in terms of their implications for attachment and mentalization theory and research, and clinical interventions.
Modes of being-there and doing-here: Transformations in self-body-environment relations in marathon runners
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This dissertation examines self-body-environment relations under conditions where the body is undergoing changes in the course of its activity. Twenty-seven marathon runners were interviewed in order to provide insight into self-body-environment relations as they undergo various transformations in training over the course of months and while racing over the course of hours. This research identifies multiple and dynamic self-body-environment relations, affecting experiences of time, space and effort, the perceptions of taskscape and landscape, and different modes of being (not-yet-able, able-restrained, unable-restrained, no-longer able, able-again) and describes bodily activities (cultivating, preparing, equipping, saving, spending).
ACUTE EFFECTS OF ESTROGEN AND BISPHENOL-A, AN ENVIRONMENTAL CHEMICAL, ON COGNITIVE AND NEURAL FUNCTION
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Many natural and synthetic chemicals in environment can mimic or antagonize the effects of endogenous hormones. Bisphenol A (BPA) is one such chemical, with mixed estrogen agonist/antagonist properties. Recent evidence indicates that estrogen and BPA may exert effects on brain functions not only through genomic but also through non-genomic pathways, activating membrane-associcated estrogen receptors. Because at present little is known about how acute BPA may interact with estrogen in the adult brain and affect estrogen mediated behaviors such as memory and learning, this research examined acute effects of estradiol (E2) and BPA, alone, and in combination, on behavior (memory consolidation) and neural function (spine density and monoamine levels) in adult ovariectomized female rats. For behavioral study, acute 17beta- and 17alpha-E2 treatment effects on spatial and non-spatial memory consolidation were tested using object placement (OP) and object recognition (OR) tasks. Both isomers of estradiol facilitated memory consolidation, but enhancement occurred in a time-, dose-, and task specific manner. The dose-response relationship was an inverted-U for both tasks. Co-administration of BPA blocked E2-induced OP memory enhancement far below the current reference safe dose of 50ug/kg/day. A larger BPA dose was needed to block 17alpha-E2 induced OR memory enhancement. BPA alone had no effect on OP memory, but high doses enhanced OR memory. To examine possible neural systems that may contribute to acute E2 and BPA treatment effects, brains were removed for neuromorphological and neurochemical analysis. Golgi impregnation 30 minutes after acute treatments showed that E2 increased apical and basal dendritic spine density in pyramidal neurons of of the prefrontal cortex (PFC), and basal, but not apical, spine density in pyramidal neurons of CA1 region of the hippocampus. Co-administration of BPA with E2 further increased apical and basal spine density in both the PFC and the CA1. Golgi impregnation 4 hours after acute treatments found that co-administration of BPA significantly suppressed E2-induced basal CA1spine density. Neurochemical analyses revealed that acute estrogen increased monoamine and metabolite levels in the PFC, but decreased these chemicals in the hippocampus. Co-administration of BPA further increased monoamine and metabolite concentrations in the PFC. In summary, the current data provide new information about acute effects of estrogen and BPA on memory and brain function. BPA interacts with E2 at very low doses, and rapidly alters behavioral and neural response to E2. These findings demonstrate BPA behavioral changes at very low doses in the membrane environment and suggest low level exposure of BPA may have a powerful, negative impact, rapidly altering behavioral and neural responses to endogenous estrogen.
Symbolic Ruptures: The Speech and Language of Trauma
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This dissertation project is a theoretical examination of `symbolic ruptures,' the traumatic disruptions in human experience that resist being represented in ordinary modes of symbolization. Insofar as the representation of such disturbing experiences is primarily non-verbal, it has been often relegated to the realm of the `desymbolic.' This project attempts to re-conceptualize the forms and symptoms in which such experiences are expressed as an unconscious language and seeks to reinstate them back into the realm of the symbolic, thus creating a new imperative for their understanding. While mainstream psychoanalytic literature has regarded symbolization as a representational process, this project expands the use of the term to connote the range of experiences and processes that connect the subject to the symbolic structures of a culture. In this sense, `symbolic ruptures' not only affect one's capacity to represent extraordinary experiences in thought and in language, but they fundamentally disrupt the subject's link to the world. It is argued, however, that the symptoms of these ruptures-- the recurring nightmares, the flashbacks, the hallucinatory experiences, etc.--remain symbolic in that they constitute an address to an other that seeks to be heard. While these symptoms may conceal or silence the traumatic event, their repetitive nature expresses the structure of the trauma. It is through the ruptures in the structure of the treatment and of the clinical setting, it is argued, that the structure of trauma may be accessed. This theoretical framework, which is highly informed by French psychoanalysis and the work of Jacques Lacan, ultimately aims to expand the way we understand and work with experiences of trauma in the clinical setting. In undertaking this project, I also hope to challenge existing views on symbolization by deemphasizing the importance of verbal representation and recognizing the symbolic potential in the non-verbal language of symptoms.
Transfer of oddity-from-sample performance in the pigeon to novel stimulus locations
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The study examined the role of stimulus location in oddity-from-sample conditional discrimination in the pigeon. A three-key discrimination procedure with vertical and horizontal lines was used. The two phases of the experiment were carried out using two groups of four pigeons. One group was trained with the sample stimulus always appearing on the center key. After a response to the sample stimulus, two comparison stimuli were presented on the remaining two keys. The second group was trained with the sample presented on one of the side keys. After a peck to the sample key, the comparisons were presented on the remaining two keys. Following acquisition of oddity, the procedures were reversed between the two groups. The birds' performance was analyzed in terms of both multiple-rule and single-rule models of conditional discrimination. The results show that oddity-from-sample conditional discrimination is best described in terms of specific, sample-comparison associations, where the location of the stimuli must be specified.