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The Effects of Prompt Fading and Differential Reinforcement on Selection of Novel Activities by Children with Autism
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Individuals with autism often show limited variability in selecting leisure activities. Repeatedly engaging in only one or a few activities may lead to decreased opportunities for social interaction and leisure skill development. The current study evaluated the effects of prompt fading and differential reinforcement on selection of novel activities (activities which had not yet been chosen during a given session), activity engagement, frequency of activity selection, and trials on which each activity was selected, in three students with autism. Prompting consisted of placing a small sticker dot below activities (or on their pictorial representations) that had already been selected during a session. Sticker size was faded systematically. The results show that the use of prompt fading and differential reinforcement for selecting novel activities increased selection of novel activities. Engagement in the activities selected was initially high for each of the three participants, and remained high throughout the study. Although the frequency of selection for each activity became more similar across activities in the post-baseline conditions for all participants, the activity with the highest average frequency of selection in baseline remained the highest throughout the study for two participants. The third participant equalized his selections so that the activity with the highest frequency of selection in baseline had the same average frequency as two other activities in all post-baseline conditions, with those having the highest overall frequency of selection. With respect to the trials on which each activity was selected, the activity chosen on the first trials in baseline continued to be chosen on the first trials throughout the study for one participant. The remaining two participants did show some shift in the activities chosen on the initial trials. This study then, demonstrates the efficacy of a treatment package in increasing the selection of activities not yet chosen in a session. The implications of these findings are discussed with regard to social validity and stimulus control of novel selection behavior.
INTER-SUBJECTIVITY AND COLLABORATIVE COMPLEXITY: EFFECTS OF PEER INTERACTION AND CONTEXT IN HEAD START CLASSROOMS
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This study provides an assessment paradigm for examining the quality of children's experiences in preschool. In particular, it focused on peer interactions, as assessed by two measures: peer inter-subjectivity and collaborative complexity. To further understand the relationship between these measures peer interactions were analyzed as nested in activity areas through hierarchical linear modeling. Teacher interactions with the peer group and environmental flexibility of the activity area were also used to explain the relationship between the peer interaction measures. Results showed that the construct of inter-subjectivity was multi-dimensional for this population and sensitive to the immediate social and material context. Higher levels of peer inter-subjectivity were found to predict longer play interactions and greater collaborative complexity. The HLM models also showed that peer interactions varied as a function of activity area, and that environmental flexibility explained some of these differences. In addition, it was found that teacher interactions moderated the relationship between inter-subjectivity and collaborative complexity. In the majority of cases teacher intervention weakened this relationship and had a negative effect on inter-subjectivity levels. In conclusion these results show the theoretical concept of inter-subjectivity to be a valid and useful measurement construct for assessing preschool peer interactions. In addition, the results show that assessments of early childhood education may want to pay more attention to the micro-contexts of the preschool day in order to capture those aspects most salient for children's development. Given that this study was done with a low income sample, it is interesting to note that many of the same findings regarding middle class preschoolers in terms of peer interactions and play were replicated. Future research may want to explore different populations of preschoolers to determine whether the same dimensions of inter-subjectivity are found. In addition, it would be useful to see whether the social skills assessed in this study are linked to concurrent or longitudinal outcomes in related domains of development.
The Interaction of Intensity and Deviance on Auditory Event-Related Potentials: Findings Using Principal Component Analysis (PCA) of Current Source Densities (CSDs)
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Mismatch negativity (MMN) studies provide insights into the brain's ability to perceive and/or detect deviations from established sensory patterns. Clinical studies investigating the loudness-dependency of auditory evoked potential (LDAEP) have shown a relationship between the intensity of an auditory stimulus and neuro-physiological or -chemical activity of the primary auditory cortex. Unfortunately, these two bodies of literature remain disjointed. The present study integrates elements of each body of literature to a) investigate the impact of varying levels of intensity deviance on N1/P2 with a standard set of intensities used in LDAEP paradigms, and b) assess the extent to which deviance-related processes (indexed by MMN) are affected by louder or softer tones. A passive MMN-paradigm used the same stimuli as deviants and standards in order to separate deviance- from stimulus-specific N1/P2 processes. A CSD-PCA approach was used to identify and quantify reference-independent patterns of activity underlying the ERP. Results show that the intensity dependence of N1/P2 is largely dependent on the context in which a given intensity was cast. Namely, a high rate of repetitions of standard intensities produce significant reductions (adaptations) in N1/P2, while N1/P2 enhancement occurred for louder, but not softer deviants. Moreover, MMN amplitude paralleled intensity disparity; however, louder deviants produced greater MMN activity than softer deviants, Intensity Modulation of N1 and MMN presumably reflecting an attentional modulation of sensory processing. A P3a-like vertex source was elicited by the loudest intensity (100 dB), but was absent for all other intensities. Insights gained from this study have direct implications for both clinical LDAEP and MMN studies. LDAEP studies should consider how overlapping or dynamic processes (e.g., adaptation of N1/P2 or elicitation of MMN) influence the amplitudes of N1 and P2. MMN studies should a) consider how attention may interact with intensity to produce distinctly different MMN responses independent of actual deviance-related processes, b) consider how P3a activity reflects a wider range of functions other than `attentional signaling,' such as response inhibition or startle-related processes, and c) consider other physiologically plausible and parsimonious explanations of MMN (e.g., sensory adaptation) when interpreting findings.
Sources of dual-task interference in visuomotor tracking assessed with behavioral and fMRI analyses
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Compensatory tracking was studied alone and simultaneous with a speeded go-no-go task using behavioral and neuroimaging with BOLD fMRI. In the dual-task condition, subjects used their right hand to track while making button presses with their left hand to respond to the secondary task. The study was replicated in two experiments. Replication was tested both behaviorally and with neuroimaging analyses using multivariate linear modeling. Tracking error and joystick velocity were binned into 640 ms and 100 ms intervals centered at secondary task stimulus onset and response in separate analyses to locate the time points at which the tracking behavior showed an interference effect due to the secondary task. Neuroimaging analyses located brain regions associated with compensatory tracking and with dual-task coordination. The binned time-series analyses revealed interference effect in joystick velocity about 200 ms before secondary task response. This finding combined with decreased activation in the left motor cortex during left hand response to a secondary task demonstrated that dual-task interference occurred in the motor preparation stage.
Three Potential Mediators of the Effects of Child Abuse and Neglect on Smoking in Middle Adulthood
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The purpose of the current study was fourfold: (1) to determine whether individuals with histories of child abuse and neglect have higher rates of current cigarette smoking in middle adulthood compared with matched controls; (2) to examine whether individuals with histories of abuse and/or neglect are at increased risk for higher rates of current psychopathology (anxiety or depression), negative coping, and past year traumas and victimization experiences in adulthood compared with matched controls; (3) to determine whether current psychopathology, negative coping, and past year traumas and victimization experiences mediate the relationship between child maltreatment and current smoking; and (4) to examine whether there are sex differences in the relationship between child maltreatment and current cigarette smoking. Using a prospective cohort design, children (ages 0-11) with documented cases of abuse and neglect during the years 1967 to 1971 were matched with children without such histories on the basis of age, sex, race/ethnicity and approximate family social class and followed up into adulthood. Individuals with histories of child abuse and neglect and non-maltreated matched controls were followed up and interviewed using a series of structured and semi-structured interviews and rating scales that included assessments of smoking behavior, current psychopathology, negative coping, and past year traumas and victimization experiences. There were multiple phases in the study. This study used data from the second set of interviews conducted between 2000-2002 and the third wave of interviews that were conducted in 2003 to 2005. Current psychopathology, negative coping, and past year traumas and victimization experiences were assessed during the second wave of interviews (M=39.5-years old). Cigarette smoking was assessed during the third wave of interviews (M=41.2-years old). Child abuse and/or neglect was associated with increased risk for current cigarette smoking in middle adulthood and was found to predict current psychopathology, negative coping, and past year traumas and victimization experiences. Only current psychopathology mediated the relationship between child abuse and/or neglect and current smoking. Separate analyses for males and females revealed significant sex differences. Child abuse and/or neglect predicted an increased risk for current cigarette smoking for females only. Child abuse and/or neglect predicted current psychopathology and past year traumas and victimization experiences for males and females, but predicted negative coping for males only. These results suggest the importance of considering the roles of current psychopathology and coping styles in cigarette smoking prevention and intervention among the maltreated population.
Living in an (In)Visible World: Lesbians' and Queer Women's Spaces and Experiences of Justice and Oppression in New York City, 1983-2008
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Lesbians and queer women are often labeled "invisible" in and beyond the academy within a politics of visibility used to describe lgbtq people and their movement. This dissertation is a historical geography of contemporary lesbian and queer society, culture, and economies in the lgbtq "mecca" of New York City. This project draws upon 22 focus groups with 47 self-identified lesbians and queer women who came out between 1983 and 2008, as well as almost a year of archival research of documents spanning the same period. From this project, I argue that lesbians' and queer women's productions of urban space take the unique form of constellations, whereby material and imagined places, experiences, and bodies understood as lesbian and/or queer serve as the nodes between which participants draw connections to work around and against patriarchal and heteronormative systems of oppression. This feminist-queer theoretical contribution affords a way to argue against labeling lesbians and queer women as "invisible" while questioning and getting beyond visibility politics as the best solution for securing lgbtq justice and justice for women. Drawing from the needs and desires of participants, I suggest a politics of visibility, recognition, and participation as the next step in promoting more just futures for lesbians and queer women.
Ego Identity Status as a Developmental Predictor of Postpartum Depression
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Ego identity formation, as proposed by Erikson (1959), is the major psychosocial task of adolescence and young adulthood. Though past research on ego identity has focused on adolescent changes, recently a new question has emerged: Does the initial ego identity formed in adolescence undergo developmental changes or reformulations during adulthood? (Berzonsky & Adams, 1999; Kroger, 1995; Marcia, 2002). This study examined changes in ego identity status (Marcia, 1966) during the transition to motherhood and its relation to the development of postpartum depressive symptoms using a two-wave longitudinal design. The dissertation also examined three potential mediators of this relationship: prenatal commitment to the pregnancy; postpartum commitment to the infant; and parenting self-efficacy. The sample consisted of 78 pregnant women between the ages of 18 to 47. Data were collected through mailed self-report questionnaires during prenatal weeks 20 to 40 (Time 1) and again during postpartum weeks 5 to 22 (Time 2). Measures included the Extended Objective Measure of Ego Identity Status-2 (EOMEIS-2; Adams, 1998) and the Center for Epidemiological Studies Depression scale (CES-D; Radloff, 1977) at both time points; the Commitment to the Pregnancy scale (Lydon, Dunkel-Schetter & Cohan, 1996) at Time 1 and the Postpartum Depression Screening Scale (PDSS; Beck & Gable, 2002), the Parenting Sense of Competence scale (PSOC; Gibaud-Wallston & Wandersman, 1978) and the Commitment to the Infant scale (developed by the author) at Time 2. Based on their EOMEIS-2 scores, participants were classified in one of four identity statuses: diffusion, foreclosure, moratorium or achievement during both the late pregnancy and early postpartum periods. There was some evidence of change in ego identity status from the pre-to post-partum period with more women changing to a less rather than a more differentiated ego identity status postpartum. Change in ego identity status was not related to postpartum depressive symptoms. In cross-sectional analyses, postpartum ego identity status was related to depressive symptoms when depressive symptoms were measured by the PDSS. However only one mediational process was identified: commitment to the pregnancy mediated the relationship between prenatal ego identity status and prenatal depressive symptoms. The PDF version of the dissertation is comprised of two separate files: the main text and the supplemental file of landscaped tables.
Narrating Hurricane Katrina: Identifying Linguistic Patterns in Survivors' Trauma Accounts
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An attempt was made to identify characteristic linguistic patterns within a sample of Katrina survivors. Meanwhile, an effort was made to assess the survivors' levels of Referential Activity (RA) and Unresolved Trauma. Though the RA measure has been utilized in several research studies, it has never before been applied to a non-clinical sample of traumatized individuals. This work also aimed to distinguish transcripts coded as "Unresolved" according to the Unresolved Trauma and Loss Scale of the Adult Attachment Inventory (AAI) from transcripts coded as "Resolved" on the basis of linguistic markers. With these multiple objectives in mind, an archival collection of 18 oral history interviews of Hurricane Katrina evacuees was subjected to narrative and linguistic analysis. The evacuees received predominantly High RA scores (relative to their individual mean RA scores) as they provided their storm accounts. This indicates some degree of absorption in their traumatic recollections. The Unresolved individuals also received overwhelmingly High RA scores, which suggests that RA may play a unique role in traumatized populations. Rather than serving as a signifier of mental health, High RA may reflect the presence of trauma-related pathology in a traumatized individual. The evacuees' use of certain linguistic mechanisms also suggested a high degree of psychological immersion in the trauma. Though the extent of traumatic immersion differed between the Resolved and Unresolved evacuees, the linguistic devices used in both sets of transcripts were fundamentally similar. This suggests that the hard categorical distinction usually made between the Resolved and Unresolved classifications might be more fluid than previously thought. Also, the results of this study demonstrated that attuned listening by clinicians might present a naturalistic method of identifying those survivors who may be at heightened risk for stress-related pathology following trauma. To this end, clinicians should pay special attention to patients' use of linguistic mechanisms (such as the use of sensory imagery, linguistic repetition, metaphors for the trauma, shifts into present tense, shifts into second-person pronouns, heavy use of dialogue, and inclusion of detail). Traumatized individuals who demonstrate excessive use of these mechanisms should be monitored closely for the development of stress-related symptomatology.
The Abilities and Differential Difficulties of Children with Autism Spectrum Disorder and Children with Specific Language Impairment to Use Semantic and Social Contexts to Infer and Recall Novel Words
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Two studies assessed the ability of 12 pre-school children with Autism Spectrum Disorder (ASD; N = 7) or Specific Language Impairment (SLI; N = 5) to use semantic context and eye gaze to infer the meanings of novel nouns, and to recall those meanings after a 24-hour delay. In Experiment 1, the children heard statements containing a familiar, transitive verb and a novel noun (e.g., "Daddy eats the artichoke"). Children were asked to point to the picture of the correct referent which was presented with 3 other novel items. On day 2, they were asked to point out the correct novel referents (e.g., "Show me the artichoke") that were now rearranged in different displays and were requested without reference to the previous semantic context. In Experiment 2, the children saw a representation of a face with eyes oriented to one of 4 items, each located in a different quadrant around the face. Children were asked about the cartoon face's desires based on the social cues provided by the eye gaze (e.g., "Sully makes the bouquet. Show me the bouquet"). On Day 2, the children were asked to point to the previously labeled items that were arranged in a new display without reference to the previous social context. All participants performed better using semantic context than eye gaze, but the children with ASD had greater difficulty with eye gaze than those with SLI. Recommendations for future training and intervention based on the results of both experiments are provided.
Interactive effects of chronic stress and alcohol intake on behavioral, physiological, and neuronal components in male and female rats
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For many individuals, exposure to stress is frequently accompanied by increased substance use. However, studies on stress and alcohol consumption often only focus on anxiety and depression to assess the interaction between these two factors. Cognitive function has been implicated in acquisition of drug abuse and thus requires further investigation. In addition to anxiety and depression, the interactive effects of stress and alcohol were evaluated on memory function using the object placement, object recognition, and Y-maze tasks. Four experimental designs used male and female rats randomly assigned to one of 4-groups: No Stress / No Alcohol Control (CON), Alcohol alone (ALC), Stress alone (STR), or Stress plus Alcohol (STR+ALC). In Aim 1, we found that restraint stress increased voluntary alcohol consumption in males and that alcohol consumption after a stressor alleviated stress-induced memory impairments in the object placement task. To control for variability in voluntary drinking, Aim 2 administered alcohol via gastric gavage (2 g/kg). Males exposed to the combination treatment (STR+ALC) had intact working and spatial memory and reduced levels of anxiety on the elevated plus maze and depression in the forced swim task (Aim 2). In contrast, females showed impaired memory and increased depression following 7-days of alcohol intake after a stressor (Aim 3). Physiological measures from male rats exposed only to the 7-day treatment (Aim 4) were consistent with some of the behavioral findings. The STR+ALC group showed adaptation of the corticosterone response from day-1 to day-7 of stress, while the other groups showed consistent corticosteroid release. Additionally, neurotransmitter receptor expression of hippocampal GABA-alpha4 and GluN2B was upregulated for the ALC and STR+ALC groups on the last day of stress, but not 3-days after stress. Overall, the interactive effects of exposure to stress and alcohol were evident in behavior in a sexually dimorphic manner. These effects may explain the increased use of psychoactive substances during times of stress and may contribute to the development of dependence. The opposing results between males and females in response to alcohol intake after a stressor suggests a need for sex specific prevention and treatment methods for chronic stress and alcoholism.