Filter Dissertations and Theses By:
Internalizing and Externalizing Pathways to Suicidality in Abused and Neglected Children
Year of Dissertation:
Cathy Spatz Widom
This dissertation examines major depressive disorder (MDD), substance abuse and/or dependence (DA), antisocial personality disorder (ASPD), and borderline personality disorder (BPD) as potential mediators of the relationship between child abuse/neglect and suicidality in middle adulthood. Children with documented cases of physical and sexual abuse and neglect (ages 0-11) during 1967-1971 were matched with non-maltreated children and followed into middle adulthood (approximately age 40). Mediators were assessed in young adulthood (approximately age 29) through in-person interviews between 1989 and 1995. Suicidality was assessed via self-report during 2000-2002 (N = 892). Logistic regressions were used to test whether: (1) Children with documented histories of child abuse/neglect (as well as specific types of abuse/neglect) were at increased risk for suicidal ideation and suicidal behavior in middle adulthood in comparison with matched controls; (2) Children who have documented histories of abuse/neglect were at increased risk for lifetime diagnoses of MDD, DA, ASPD, and BPD in comparison with matched controls; and (3) Diagnoses of MDD, DA, ASPD, and BPD mediate the relationship between child abuse/neglect and suicidality. Interactions for sex and race were also examined and separate analyses were conducted for males, females, Blacks, and Whites. Child abuse/neglect was associated with increased risk for suicidality in middle adulthood and only MDD mediated the relationship between child abuse/neglect and suicidality. When specific types of abuse/neglect were considered, ASPD mediated the relationship for neglect and suicidality, while MDD and BPD mediated the associations for physical abuse and suicidality and multiple forms of maltreatment and suicidality. Separate analyses for males and females revealed significant sex differences. MDD acted as a mediator between child abuse/neglect and suicidality only for females, BPD was a mediator between child abuse/neglect and suicidality for males, and ASPD was a mediator for both abused/neglected males and sexually abused females. While MDD significantly mediated the relationship between child abuse/neglect for Whites, none of the diagnoses mediated the relationship between abuse/neglect and suicidality for Blacks. These results suggest the importance of considering the roles not only of internalizing symptoms but also of externalizing symptoms in suicide risk assessments among the maltreated population.
Daytime Napping: Effects on Relational Memory
Year of Dissertation:
DAYTIME NAPPING: EFFECTS ON RELATIONAL MEMORY by Hiuyan Lau A plethora of theoretical models and empirical data suggest that sleep strengthens various types of memory. However, the role of sleep in a fundamental feature of memory, relational memory - the flexible representation of items not directly learned prior to sleep - is less clear. At the same time, the effect of daytime naps - relatively brief periods of diurnal sleep - on memory is not well explored. In the present research, a series of three studies were conducted to investigate the effect of daytime napping on three different forms of relational memory: 1) inferential associations of separately learned items, 2) the abstraction of general concepts, and 3) relational memory built on shared contextual elements. Results from all three studies indicate that daytime napping facilitates relational memory. In addition, Study II demonstrates that the effect of daytime napping on relational memory is not dependent on whether the nap immediately follows learning or occurs after a brief (approximately two hours) delay. However, the significant difference in task performance between subjects with and without a nap is not sustained after one week, as shown in Study III. Consistent with the majority of existing literature, slow wave sleep, among all sleep stages, appears to be the strongest contributor to relational memory. Yet it alone cannot fully explain the effect of sleep on relational memory, suggesting that mechanisms independent of sleep stages may be involved. Overall, the results from the present research imply an active role for sleep in multiple memory processes that are not limited to the mere strengthening of memories, but also the binding and reorganizing of separately learned memory traces for flexible use at a later time.
The Influence of Naive and Media-Informed Beliefs on Juror Evaluations of Forensic Science Evidence
Year of Dissertation:
The National Academy of Sciences (2009) concluded that with the exception of nuclear DNA, none of the forensic sciences has been scientifically validated. It is not clear, however, that people are aware of these deficiencies. Indeed, people tend to think quite highly of forensic science, and find it to be convincing trial evidence. It is not clear to what extent their erroneous beliefs about validity influence the weight given to such evidence, or how best to challenge these beliefs. In the present research, I examined people's beliefs about forensic science and how their beliefs influenced their evaluations of forensic evidence. I also investigated the most effective ways to challenge their beliefs either during the trial (i.e., via cross-examination) or prior to the trial (i.e., via the media). In the first part of the project (Study 1), I investigated pretrial reliability beliefs, and the influence of DNA, fingerprint, toolmark, and bitemark evidence in a homicide trial. The evidence matched or did not match the defendant and was countered by non-substantive, expert-focused, or evidence-focused cross-examination. Forensic evidence was viewed as more reliable than non-forensic evidence, and reliability beliefs influenced people's perceptions of the evidence. Although participants had some awareness of the comparative reliability of different disciplines, they tended to give too much weight to less valid disciplines. Further, evidence that matched the defendant was viewed as higher quality than evidence that did not match. Although cross-examination made people more skeptical of the forensic evidence, it did not reduce guilty verdicts. In the second part of the project, I investigated the effectiveness of fact-based (Study 2) or story-based (Study 3) media reports in challenging people's beliefs about the validity of bitemark evidence, and whether reading such reports could help them to evaluate forensic evidence more appropriately. I found that a report which used complex language and attacked bitemark evidence from several angles was the most effective fact-based report. An illustrative story by itself was ineffective, but when the story was supplemented with factual information, it appeared to be the more effective than facts presented alone. Possible implications of these findings are discussed.
PARENT-CHILD DYADIC PLAY AND DEVELOPMENT:
Year of Dissertation:
In this study, dyadic play in a culturally diverse sample was observed and coded. Thirty mother-child dyads participated, of which 10 were Chinese immigrant families, 10 Hispanic immigrant families and 10 were native born Caucasian Americans. The age of the mothers ranged from 23-39 (M = 31, SD 3.81) age of the fathers from 25-41 (M = 33.34, SD 4.40). The age of the children ranged from 18 - 36 months, (M = 26.70 months, SD 6.05). Of the 30 children, 17 were male and 13 were female. The education level of parents ranged from Junior High School through Graduate School and was well balanced across all groups. Twenty four of the 30 children in the study had siblings. Eight of the children in the study received a therapeutic service and siblings of 7 of them were reported to have received a therapeutic service. Fifteen families reported that they had private health insurance: Medicaid status was used as a proxy for income. A questionnaire of Parental Beliefs about Play and Development was completed as well as an observation of parent-child play. The type of play, child behaviors and level of parental scaffolding were coded to determine the relationship between the parents' responses to the questionnaire and their actual play. Responses to the questionnaire were summarized to form 3 groups -- parents who believed that play and development were interactive, that development was fixed, and that development was based solely upon maturation. Parents who believed that play and development were interactive demonstrated higher levels of scaffolding behavior of their child in play F(2,27) = 4.74 p<0.01. There was no effect observed for socioeconomic status or the presence of a disability upon parental beliefs; there were some differences in beliefs about development by ethnicity. The focus of this study was not to reveal cross cultural differences but rather, to ensure that there was enough cross cultural representation to demonstrate that the findings are likely to apply to parents in general, rather than to parents belonging to a specific SES, race or culture.
ECOBEHAVIORAL DIMENSIONS OF JAYWALKING: JAYWALKER-CAR COLLISIONS AS A FUNCTION OF THE SOCIO-SPATIAL CONTEXT
Year of Dissertation:
A three-level hierarchical model assessed the combined effects of a multilevel approach to the explanation of injury severity in a sample of jaywalker-car collisions that occurred in New Jersey between 2006 and 2009. First-level units were individual jaywalkers who were involved in the collisions. Second-level units were the road segments (spots) of approximately 0.5 miles radius around the point at which at least one collision occurred. The third-level units were municipalities having had at least one collision. Results indicate that younger jaywalkers, those who wear light clothes, those who cross the road without running or darting, those who are not under the influence of drugs or medication, and those who collide with drivers not driving in a straight strip of road tend to receive less severe injuries. Along with the individual-level factors, significant interaction of some of the second and third-level predictors was found. When roads were dry, wearing light clothing minimizes the severity of injuries. When jaywalkers were under the influence of drugs or medication, greater sidewalk coverage helped to reduce the injury severity. When fewer cars were parked on the roadside to protect against speeding drivers, wearing clear clothing helped to reduce injury level. No moderation effect was found of macro-level factors on micro-level variables predicting injury level. Nonetheless, environmental features like sidewalk coverage, recreation areas nearby, distance to public transportation, population density, and poverty contributed significantly to explain severity of injuries.
Early Sensory Processing Deficits in Schizophrenia
Year of Dissertation:
Sensory processing deficits have been found in individuals with schizophrenia across sensory modalities, including auditory, visual, somatosensory, and olfactory systems. These deficits have been identified at very early stages of cortical, and subcortical processing. It remains to be seen whether or not these deficits have implications for higher order cognitive processes and the positive and negative symptoms of schizophrenia. Before we can begin to understand the role they play in the etiology and manifestation of the disease, the deficits themselves must be fully characterized. Three high-density (168-channel) electrophysiological investigations are detailed herein, the first two of which are concerned with the auditory system, and the final, the visual system. First, we present an investigation of the middle latency auditory evoked potentials, a processing period which has not previously been explicated in the schizophrenia literature, and one which represents the transition from brainstem-level processing to late-latency cortical processes. Next, we present a normative investigation of the ventral and dorsal (`what' and `where') auditory pathways which employed functionally distinct behavioral tasks in an attempt to characterize the evoked componentry within each of the respective pathways. On the basis of the notion that dorsal and ventral pathways show differential impairment in individuals with schizophrenia, the paradigm was then applied to a group of patients to determine whether the pattern of processing within the two pathways differed from that observed in healthy controls. Finally, we present a visual experiment that employed a monocular deprivation challenge as a means of amplifying known early visual processing deficits in schizophrenia, namely the visual P1 deficit which was recently identified as an endophenotypic marker for schizophrenia. Taken together, the deficits that were identified and characterized within each of these sensory modalities may contribute to an overarching model of sensory processing deficits in schizophrenia wherein the contributions of many decrements, taken together across sensory modalities, result in a profile common to individuals with schizophrenia.
VEGF treatment during status epilepticus alters long-term hippocampal astrocyte morphology: A detailed description of astrocyte morphology and glutamate transporter patterns with and without administration of VEGF and seizure induction
Year of Dissertation:
VEGF treatment during pilocarpine-induced status epilepticus (SE) causes enduring preservation of behavioral function in rats in the absence of enduring neuroprotection (Nicoletti et al., 2010). In addition, VEGF treatment reduces hyperexcitability in hippocampal slices without altering neuronal membrane properties (McCloskey et al, 2005). Combined, these data suggest the possibility that other cells or mechanisms could be involved in the beneficial effects of VEGF during SE. Our laboratory is interested in the potential contribution of astrocytes to these effects. Astrocytes are not only reported to contribute to epileptiform discharges in the hippocampus (Tian et al., 2005; Kang et al., 2005) but also to express VEGF receptors (Krum & Rosenstein, 2002). We previously reported that VEGF treatment significantly alters multiple astrocyte parameters such as cell soma size, branching complexity, branch volume, number of dendrites, nodes counts and highest order branching after SE. The current study investigated both astrocyte morphology and glutamate transporter expression one month after SE in animals treated with VEGF or inactivated VEGF during SE. Individual GFAP-immunostained astrocytes from both CA1 and the dentate gyrus hilus were traced using Neurolucida software (Microbrightfield Inc.), allowing morphological parameters to be analyzed via Branched Structure and Sholl analyses. In addition, Image J software was used to measure optical density in GLT1 (glial glutamate transporter 1)-immunostained sections. VEGF treatment during SE significantly prevented post-SE increases in number of branch intersections, process length, and node count. Furthermore, an analysis of the distance to the nearest neighboring astrocyte revealed that VEGF treatment significantly increased inter-astrocyte distance. GLT1 immunoreactivity in VEGF treated animals was decreased compared to seized controls. VEGF treatment did not significantly alter the shape of the astrocytes but rather the branching complexity and size. Because cell morphology impacts cell physiology, it is possible that VEGF's enduring effects on post-SE astrocyte morphology impacts the functioning of the post-seizure hippocampus.
EATING THE CITY: FOOD ENVIRONMENTS, INEQUALITY, AND THE DAILY JOURNEYS OF EATERS IN NEW YORK AND LONDON
Year of Dissertation:
Municipal policies aiming to improve equity in food access and health often rely on the assumption that neighborhoods with limited availability of healthy foods and high levels of diet-related illness should be the targets for change. However, food systems planners have used the 'local trap' to caution that there is nothing inherently beneficial about the local or any other scale of action with regard to improving the social justice, ecological sustainability, or public health outcomes of food systems. This study examines the local trap argument in the food policy contexts of New York and London. It asks: Are there comparable inequalities in food environments of New York and London? How do individuals living and working in the highest and lowest income areas of these cities perceive, navigate, and use the food environment? How does local, or neighborhood, food availability influence access to food and health? This study employed a cross-national, comparative, and mixed-method design. A total of 110 food establishments were observed in the study areas. The number and type of establishments in the study sites reflected the income of residents. The types of food available reflect the place-types present as well as the demography of local areas. To gather narrative and spatial data about everyday experience and food events, space-time food diaries, mental mapping, and semi-structured interviews were collected from a total 40 participants. Space-time food diaries and mental maps were analyzed to determine the proportion of in- and out- of neighborhood food events. Individual participants operationalized neighborhood boundaries in their mental maps of the study sites. There was a variation across individuals with regard to the percentage of in-neighborhood food events they reported in the space-time food diaries. Findings show that neighborhood food environments are meaningful determinants of diet for diverse eaters, but eaters' usages, perceptions, and identifications with the food environment operate across a range of geographic scales. They suggest that neighborhood social and economic integration may be a determinant of urban food environments. Thus, definitions of urban food policy should include those housing and community development policies that impact neighborhood social and economic diversity.
The Effects of Code-Based Literacy Interventions on Spelling Achievement: A Meta-Analysis
Year of Dissertation:
Poor spelling is a pervasive problem among children and adults alike. Yet despite an abundance of research on reading development, there is a surprising lack of emphasis on spelling, a related and arguably equally important skill. Given that research in the past two decades has established the importance of code-based knowledge such as phonological and alphabetic knowledge in reading, it is reasonable to suspect that code-based knowledge would also impact spelling ability. However, few intervention studies have directly addressed spelling. To investigate this issue, this study utilizes meta-analysis to quantitatively assess the effects of systematic code-based literacy interventions on spelling achievement. Studies included in the meta-analysis were published in English, involved a code-based literacy intervention in a school setting, included a control or comparison group, measured spelling as an outcome at post-test, and reported sufficient statistics to compute effect sizes. Random effects analysis models were based on 91 studies and 153 computed effect sizes. The mean effect size for all studies was moderate, d = 0.58, 95% CI [.49, .67], indicating that systematic code-based literacy instruction is more effective at improving spelling outcomes than non-code-based or less systematic code-based instruction. The total sample size was 9,341 participants in pre-school to Grade 11. These findings directly oppose the claim that learning to spell is a passive process that occurs in all literacy contexts, as well as lay assumptions that knowledge about spelling does not need to be taught. Rather, the findings from this meta-analysis suggest that students who had received interventions that incorporated explicit instruction in phonological, orthographic, morphological knowledge fared better than their control-group peers on spelling outcomes. However, given the limitations of meta-analysis, further research is needed to substantiate these findings. Overall, evidence from this meta-analysis suggests that spelling, like reading, is best improved by explicit instruction in linguistic knowledge.
Recovery Trajectories of Women with Co-Occurring Post-Traumatic Stress Disorder and Substance Use Disorders
Year of Dissertation:
Over the past ten years interventions utilizing an integrated model of treatment for co-occurring PTSD and SUD in women have emerged to address the links between trauma and addiction. The current study applied a longitudinal, dynamic lens to 353 women dually diagnosed with SUD and PTSD in an effort to classify common trajectories of substance use during the first 12 months following treatment. As a secondary analysis of the largest behavioral trial to date for the concurrent treatment of PTSD and SUD in women (Hien et al., 2009), the present study utilized latent growth mixture models (LGMM) with multiple groups to estimate substance use patterns after treatment in order to further clarify the phenomenon of recovery for traumatized substance users. Results from the growth mixture analyses provided support for three distinct trajectories of use and recovery in the post-treatment year. Findings highlight the necessity of accounting for heterogeneity in post-treatment substance use and the relevance of incorporating methodologies like LGMM when evaluating treatment outcomes.