Filter Dissertations and Theses By:
DIFFERENTIAL RELATIONSHIPS OF MISMATCH NEGATIVITY AND VISUAL P1 DEFICITS TO PREMORBID CHARACTERISTICS AND FUNCTIONAL OUTCOME IN SCHIZOPHRENIA
Year of Dissertation:
Abstract DIFFERENTIAL RELATIONSHIPS OF MISMATCH NEGATIVITY AND VISUAL P1 DEFICITS TO PREMORBID CHARACTERISTICS AND FUNCTIONAL OUTCOME IN SCHIZOPHRENIA By Tamara Friedman Adviser: Daniel Javitt, M.D., Ph.D. Sensory deficits have been consistently observed in patients with schizophrenia, and previous studies have explored relationships between either auditory or visual deficits and various clinical characteristics and patients' global functioning. The present dissertation is the first to assess with EEG both auditory and visual deficits in the same patient sample and to relate each type of deficit to symptoms, present functioning, and premorbid functioning. The first study assessed visual deficits associated with schizophrenia during the concurrent presentation of auditory and visual stimuli. Patients with schizophrenia and healthy controls were presented with both parvocellularly-biased and magnocellularly-biased stimuli while passively listening to an auditory paradigm intended to elicit mismatch negativity responses. By comparing the present visual results to those of a very similar study, which included different visual stimuli, we underscore the importance of utilizing appropriate stimuli in assessing visual deficits in patients with schizophrenia. The purpose of the second study was to assess auditory deficits associated with schizophrenia. Duration, frequency, and intensity deviants were embedded in the auditory mismatch negativity paradigm to which the participants listened during the visual task. Mismatch negativity deficits were assessed, relative to each of the three deviants. We demonstrate that the mismatch negativity results are characteristic of patients with schizophrenia, regardless of the simultaneous visual task in which the participants are engaging. The third study relates the findings of the auditory and visual deficits in patients with schizophrenia to clinical characteristics, including symptoms, present, and premorbid functioning. Differential relationships suggest that different underlying pathophysiological mechanisms may account for impaired visual and auditory neurophysiological dysfunction. This knowledge could help in the treatment and management of schizophrenia.
Cisgenderism in Gender Attributions: The Ways in Which Social, Cognitive, and Individual Factors Predict Misgendering.
Year of Dissertation:
The current program of research investigated the ways in which social representations of gender, cognitive processes, and individual factors can be integrated to predict "misgendering," an example of cisgenderism in which people are categorized as a gender with which they do not identify. I proposed an (In)consistency Processing Model of Gender Attribution in which perceivers make a gender attribution by interpreting the stereotype-(in)consistencies of a target's gender characteristics through either a biology- or identity-based schema. Five studies were conducted to test different aspects of this model, the first of which was a secondary data analysis on a sample of students from Hunter College who participated in the lab. Participants from the remaining studies participated online and were recruited from Amazon's Mechanical Turk. Participants were more likely to reject a target's gender identity when the target's genitals and chromosomes were stereotype-inconsistent with the target's gender identity. Gender judgments were made quickly overall, but slower when target characteristics were stereotype-inconsistent. In other words, people processed gender consciously, rather than automatically, when characteristics were unexpected. Participants who knew transgender people were less likely to misgender and faster at making gender judgments, but only when targets had stereotype-inconsistent chromosomes suggesting limitations to the knowledge they gained from their contact with transgender people. Allies to transgender people and people with less gender essentialist beliefs were less likely to misgender people and did so with similar response times to the rest of participants, suggesting they spent time consciously attempting to affirm targets gender identity. People who were initially found to be less likely to misgender ("adjusters") were more likely to misgender when their efforts to affirm target identity were constrained by a distraction or by added stereotype-inconsistent information about the target. Study findings imply that cisgenderism operates implicitly on the gender attribution process. While some people may be able to temporarily focus their efforts on affirming people's genders, these efforts are conditional and easily destabilized. These findings have important practical implications for researchers, activists, service organizations, and governments invested in the ethical recognition of people's own gender self-designations.
Motor Control Mechanisms of Whisking in Rat
Year of Dissertation:
Rhythmic movements underlie a large number of critically important motor behaviors. How different levels of neural organization and control interact to produce these movements, then, is a central question in motor control. Using the whisker system in rat we investigate the role played by the motor cortex, a key structure in the generation of complex movements, in the control of whisking. We begin by measuring the movements of the whiskers and the mastacial pad, controlled by the intrinsic and extrinsic muscles, respectively, to clarify the interaction of these two components in the organization of whisking. We find that though both contribute to movement kinematics, the whisker alone makes a relatively larger contribution. We next investigate the relationship between local field potential activity and exploratory whisking and find that brief increases in vMCx activity precede both whisking onset and changes in whisking patterns. Lastly, we investigate the relationship between unit activity in the rhythmic subregion of vMCx and whisking in head-fixed rats engaged in one of two behavioral tasks. We find that spike rate is most often correlated with whisking amplitude/velocity, and that this relationship is independent of behavioral context. We also find occurrences of significant coherence between whisker movements and unit activity, which vary with behavioral task. These results suggest that, though the motor pattern underlying whisking is generated subcortically, vMCx plays a role in both initiating movement and modulating kinematic properties of whisking.
THE IMPACT OF MOOD DISORDERS ON COGNITIVE FUNCTION IN POSTMENOPAUSAL WOMEN UNDERGOING TREATMENT FOR EARLY-STAGE BREAST CANCER
Year of Dissertation:
PURPOSE: Many post-menopausal women who are treated for early-stage breast cancer report experiencing cognitive difficulties following adjuvant chemotherapy. However, the generalizability of the results of a number of studies that have attempted to document the association between adjuvant chemotherapy and cognitive dysfunction has been limited due to inconsistencies in the investigative methods used, thus introducing the possibility that other factors are contributing to reports of cognitive problems. The current study examines the possibility that a history of mood disorders in post-menopausal breast cancer patients predisposes them to cognitive difficulties following adjuvant treatment. METHODS: Sixty-five postmenopausal women with non-metastatic breast cancer were administered the SCID-I before adjuvant therapy (Time 1) to determine psychiatric status. Thirty women were found to have a history of mood disorder, while thirty-one women were found to have no history of mood disorder. Participants were administered neuropsychological tests before adjuvant therapy (Time 1), six months after treatment (Time 2), and at a final six-month follow-up (Time 3). Cognitive domains measured included motor, language, attention/concentration/working memory, visuospatial, memory (verbal and visual). RESULTS: Group comparisons found significant differences in several domains at Time 1 (attention) and Time 2 (visual spatial and visual memory), but in each case the mood disorder group means were higher than the group means of the non-mood disorder group. No significant results were found at Time 3. CONCLUSION: In postmenopausal women, a history of mood disorder was associated with higher performance in selected cognitive domains. Reasons for these paradoxical results are explored and suggestions for future research are proposed.
Stigma, Intimacy, and Well-Being: A Personality and Social Structures Approach
Year of Dissertation:
There is widespread belief that intimacy and romantic interpersonal relationships are not as meaningful for individuals in or pursuing same-sex relationships as they are for heterosexual individuals. These unfounded stereotypes and assumptions create social stressors in the form of macrosocial and interpersonal stigmatization in lesbian, gay, and bisexual (LGB) individuals' lives. Thus far, social scientists have established general negative associations between experiences of stigmatization and relationship quality among LGB individuals. However, little is known about the processes through which stigma becomes meaningful in the lives of LGB individuals and its resulting impact on their experiences of intimacy and psychological well-being. This dissertation addressed two primary aims: (a) to systematically investigate similarities and differences in LGB and heterosexual individuals' meanings and experiences of intimacy; and (b) to understand the mechanisms that link stigma-related processes to LGB individuals' lived experiences of intimacy and the resulting implications for their relational and psychological well-being. Two mixed-method studies using purposive national online samples addressed these aims. The results of both studies demonstrated that intimacy was experienced as equally meaningful among LGB and heterosexual individuals; however, LGB individuals experienced significantly more adversity in the form of stigma-related processes associated with intimacy compared to heterosexuals. Both studies showed that stigma-related processes were negatively associated with LGBs' experiences of intimacy, relationship quality, and psychological well-being. These associations were partially mediated by the meaningfulness LGBs attributed to their pursuits and experiences of intimacy. Study 2 further demonstrated that individuals in same-sex couples make meaning of their experiences of stigma and intimacy via multiple narrative strategies. Some of these strategies reinforced the negative impact of stigmatization on intimacy, while others allowed individuals to cope with, resist, and overcome stigma-related processes. These findings bolster existing research on stigma and intimacy among LGB individuals. They also challenge researchers to broaden their approaches to address the multiple pathways and mechanisms through which stigma impacts the lives of marginalized individuals. Furthermore, this dissertation demonstrates the utility of a personality and social structures approach to the study of stigma, thereby highlighting important implications for intervention and policy reform.
Therapists' Use of their Visual Images in Therapy
Year of Dissertation:
Therapists frequently experience a spontaneous appearance of a picture or sequence of pictures in their minds, while listening to their patients; in this research project I refer to these experiences as Therapists' Visual Images. The roles that these visual images play in the process of therapy may vary between different therapists, patients, and contexts. The goal of this study is to expand the theoretical understanding of this phenomenon that is common among therapists, but had not yet been studied using a controlled research. This study will examine the scope of the use of visual images that therapists experience during sessions and the processes that lead to these various uses of the image. 15 therapists were interviewed about their experience of having spontaneous visual images in sessions. They were asked about their thoughts and feelings about the experience as well as their use of their images in sessions. The data was coded and distributed to four domains representing the process of the appearance of the image: 1. Before the Image; 2. The Image; 3. After the image; and, 4. Therapists' Theories of the Functions of Visual Images. In further analysis of the results, several processes of visual images were found, resulting in different types of images: Associative Images, Symbolic Images, and Defensive Images. These processes were found to be related to different uses of the image. These finding as well as the limitations of this study are discussed.
Getting into character: Cultivating identities in a teen-theatre peer-education program
Year of Dissertation:
This study investigated the role of community theatre participation on adolescent and young adult identity development. The theatre program, known as The SOURCE, focuses on sex-education through a peer-education model. The experiences of young adults, who are now aged 18-34, were examined through interviews (N=20), identity maps (N=9), and a survey (N=64) in order to understand how participation in this group influenced their development. While much of the literature documents the successes of such programs while youth participate, few document the longer-term impacts of such participation (Saldaña, McCammon, Omasta, & Hines, 2011). Data reveal how such involvement informed the youths' developing social and interpersonal lives, and their broader understanding of self. The findings show four broad effects that span micro- to macro-level contexts. First, The SOURCE is a unique "safe space" for youth, co-constructed by KT (the director) and the engaged youth, that privileges youth voices and experiences. Second, participation in the theatre program provides an opportunity for developing counternarratives of what it means to be an adolescent, how adolescents and young adults can act as social agents in their communities, and how sex education through peer-education methods can present such opportunities. Third, the findings show that theatre is a particularly valuable medium for engaging in developmental processes because it affords the participants opportunities to "play" with identity while simultaneously expressing emotions and experiences, in addition to learning empathically about the diversity and multiplicity of others. Finally, The SOURCE experience becomes embodied in ways that inform future decisions, identity development, and personal relationships. Narrative analysis of these findings and the mechanisms of such persistence, or "traveling power of self," are discussed. While these findings are encouraging for The SOURCE and from a positive youth development standpoint, they raise important questions about limiting such spaces through broader policies and budget reductions. It is suggested, in the conclusion of this dissertation, that removing the opportunities for participation in such spaces for youth amounts to a "relational injustice," which may have long-term developmental implications.
Yes we can: A dyadic investigation of cognitive interdependence, relationship communication, and optimal behavioral health outcomes among HIV serodiscordant same-sex male couples
Year of Dissertation:
Research suggests that couples who adopt a "we" orientation in relation to illness demonstrate greater resiliency and an increased capacity to cope with stressors. HIV serodiscordant couples (one partner is HIV-positive, the other is HIV-negative) have been identified as a critical mode of HIV transmission. The present study integrates dyadic coping models and interdependence theory to examine whether cognitive interdependence (i.e., the extent to which couples include aspects of their partner into their self-concept) and communication strategies are associated with sexual behavior, antiretroviral therapy (ART) adherence, depressive symptoms, sexual satisfaction, and relationship satisfaction. The study also tested whether the associations between cognitive interdependence and behavioral health outcomes were mediated by each partners' reports of communication strategies. Further, this study qualitatively examined relationship dynamics in relation to behavioral health outcomes among a subsample of couples with different levels of cognitive interdependence. Data involved secondary analyses from the Duo Project (R01-NR010187; PI: Mallory Johnson). Quantitative analyses were guided by a multilevel structural equation modeling approach appropriate for dyadic data, and thematic analyses were used for qualitative data. For both partners, cognitive interdependence was associated with greater relationship satisfaction and lower depressive symptoms. For both partners, cognitive interdependence was associated with their partners' greater relationship and sexual satisfaction. Over-time mediation hypotheses were supported for relationship satisfaction, indicating that those who reported higher levels of cognitive interdependence also reported higher levels of positive communication, and in turn, higher levels of relationship satisfaction. Mediation was not found for sexual behavior, ART adherence, depressive symptoms, or sexual satisfaction. Qualitative analyses suggested that couples' who held congruent levels of cognitive interdependence appraised HIV and other health events as a shared stressor and engaged in effective communal coping strategies around ART adherence and sexual behaviors. The results of this study suggest that cognitive interdependence represents an important step in understanding couples' health threat appraisals, transformation of motivation process, and support strategies to promote better health behaviors. Findings have important practical implications that can be incorporated into biomedical prevention strategies, such as Treatment as Prevention (TasP) and Pre-Exposure Prophylaxis (PrEP), for same-sex couples affected by HIV.
Towards a new model of intervention with Latino families surviving domestic violence
Year of Dissertation:
Attempts to understand and explain domestic violence have traditionally focused on biological, psychological and sociological models. These multi-modal perspectives have not completely succeeded in providing a truly integrated perspective of Latino families struggling with domestic violence, as they often fail to adequately acknowledge the impact of language, poverty, and undocumented status on the survivors' ability to overcome domestic violence. The goal of this study was to attempt to create a more effective treatment model by leveraging the knowledge and skill sets of those who work most closely with these families in crisis: the direct care workers. The participants, which consisted of the direct care staff of the Latino Domestic Violence Program (LDVP), were interviewed individually, and the data was analyzed in accordance with grounded theory methodology. The participants' responses were not only informative and moving, but also served to bring to the fore a number of important issues that might otherwise have been overlooked. The participants helped identify two main elements that needed to be part of an ideal program. First, the program must be equipped to address all the biopsychosocial needs experienced by the family. These include financial, occupational, educational and mental health needs. Undocumented and non-English speaking clients' needs must be also considered when developing a program for Latino families. Second, it is important that the staff be trained in various theories/models which include an in depth understanding of the clients' culture and where there may be a clash between the values and assumptions of these culture and mainstream America.
The Effects of Prompt Fading and Differential Reinforcement on Selection of Novel Activities by Children with Autism
Year of Dissertation:
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.