Alumni Dissertations

 

Alumni Dissertations

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  • SUPRASPINAL AND SPINAL MECHANISMS OF MORPHINE-INDUCED HYPERALGESIA

    Author:
    Caroline Arout
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    Benjamin Kest
    Abstract:

    Morphine is the most prominent pharmacological treatment for moderate to severe pain in both acute and chronic paradigms. However, morphine notoriously elicits a paradoxical state of increased pain sensitivity known as hyperalgesia that complicates its use in clinical application. Research over the past three decades has reported that morphine-induced hyperalgesia is dose- and sex-dependent, and likely involves the synchronous activity of several neural networks beyond the opioid system. Whereas systemic, supraspinal, and spinal administration of morphine all cause hyperalgesia that is differentially reversible by N-methyl-D-aspartate receptor (NMDAR) antagonists or melanocortin-1 receptor (MC1R) antagonists, it is unknown as to whether or not these non-opioid systems that contribute to this state are located supraspinally or spinally. The current studies were performed with the goal of elucidating the precise location of regulatory action of this sex- and dose- dependent state of morphine hyperalgesia. In all studies, outbred CD-1 male and female mice were pretreated with the general opioid receptor antagonist, naltrexone (NTX) 24 hours prior to morphine treatment. All mice were subsequently implanted with osmotic pumps, continuously dispensing a low (1.6mg/kg/24h) or high dose of morphine (40mg/kg/24h). As noted previously, mice of both sexes were hyperalgesic by Day 4 of continuous infusion of either morphine dose, a state that persisted through Day 6 of infusion. The first series demonstrated that NMDAR and MC1R systems that mediate this morphine-induced hyperalgesic state are located supraspinally, as intracerebroventricular injections of MK-801 and MSG606, respectively successfully reversed hyperalgesia during a one-hour testing period. A second series of studies investigated possible involvement of spinal systems. Whereas intrathecal MK-801 significantly reversed hyperalgesia in males at both doses, and females at the low morphine infusion dose, spinal administration of MSG606 significantly reduced hyperalgesia in females following continuous high dose morphine infusion. This indicates that the sex-dependent mechanism involved in morphine-induced hyperalgesia is located supraspinally and spinally, and either locus can independently modulate female-typical hyperalgesia. A third series of studies investigated hormonally-regulated mechanisms involved in morphine-induced hyperalgesia. Ovariectomized females displayed male-typical patterns of hyperalgesia after i.c.v. and i.t. antagonist injection paradigms following continuous infusion of either dose of morphine on Day 4. On Day 6, NMDAR and MC1R antagonist injections were preceded by an acute systemic progesterone injection in ovariectomized female mice, and intact male mice. Following continuous morphine infusion, ovariectomized females displayed male-typical patterns of hyperalgesic reversal. However, following progesterone administration, hyperalgesia elicited by high doses of morphine was reversed by i.c.v. injection of MK-801 and MSG606 in both males and ovariectomized females. Conversely, following i.t. injections the data show that ovariectomized females are able to recruit the NMDAR or MC1R system, while males exclusively used the NMDAR system to mediate hyperalgesia. The current studies indicate that in terms of modulating morphine-induced hyperalgesia, there are both supraspinally- and spinally-regulated sex-dependent effects that mediate morphine-induced hyperalgesia.

  • Cerebrospinal Fluid Biomarkers for the Differential Diagnosis of Normal Pressure Hydrocephalus and Alzheimers Disease

    Author:
    Stephanie Assuras
    Year of Dissertation:
    2010
    Program:
    Psychology
    Advisor:
    Lisa Ravdin
    Abstract:

    Differential diagnosis of Idiopathic Normal Pressure Hydrocephalus (NPH) is complicated by symptomatic overlap with neurodegenerative conditions such as Alzheimers Disease (AD). Efforts to improve diagnosis through the use of cerebrospinal fluid (CSF) biomarkers have led to the identification of more than a dozen potential diagnostic markers for NPH. However, no single biomarker has proven sufficient for differential diagnosis in clinical practice. The current study uses proteomic analysis of CSF to identify sets of protein markers that are expressed differentially in NPH and AD. Two-dimensional gel electrophoresis was used to analyze the CSF of 8 probable NPH and 8 probable AD patients. Gels were stained with SYPRO Ruby and the percentage volume of over 1339 spots was determined. The Random Forest statistical method was used to identify proteins that optimally segregated NPH cases from AD. Protein identification was achieved by the use of a previously published CSF map and mass spectrometry. Eleven protein spots were found to optimally distinguish the groups, correctly classifying 100% of all NPH and AD samples. Of the 11 proteins of interest, six were identified and include the following: beta-trace, serum albumin A, serum albumin B, apolipoprotein A-IV precursor, pigment epithelium-derived factor, and complement component 3 precursor. The current study identifies CSF biomarkers that differentiate between NPH and AD cases. The highly successful separation of cases obtained in this study suggests that multiplexed CSF markers have the potential to improve the differential diagnosis of NPH from one of its most common competing diagnoses.

  • INTERPERSONAL RHYTHMS DISRUPTED BY A HISTORY OF TRAUMA: AN IN-DEPTH CASE STUDY OF ANALYTICAL MUSIC THERAPY

    Author:
    Tanja Auf der Heyde
    Year of Dissertation:
    2012
    Program:
    Psychology
    Advisor:
    Steven Tuber
    Abstract:

    Abstract INTERPERSONAL RHYTHMS DISRUPTED BY A HISTORY OF TRAUMA: AN IN-DEPTH CASE STUDY OF ANALYTICAL MUSIC THERAPY by Tanja Maud Christine Auf der Heyde Advisor: Steven Tuber, Ph.D. This dissertation project is a phenomenological study of interpersonal rhythms within the music therapy treatment of a client with a history of cumulative trauma. An attempt was made to explore whether and how rhythmic interactions within musical improvisations facilitate the repair of ruptures in such rhythms. Towards this aim, the rhythmic interactions between the two participants were analyzed to find evidence for bi-directional rhythmic co-regulation and loose mid-range coordination. Furthermore, this study tracked shifts in the client's mental state by applying a moment-to-moment analysis of the music with four Improvisation Assessment Profiles (IAPs). It was found that musical improvisation allows for ample opportunities for bi-directional co-regulation and loose mid-range coordination. Most of the mental state ratings were within the "optimal arousal state," suggesting that music does, in fact, facilitate regulation on both intrapsychic and interpersonal levels. However, this study also uncovered the importance of spontaneous and planned disruptions in rhythmic interaction, which find their musical expression in syncopations, polyrhythms, and a-rhythmic sections. These experiences are deeply embedded in the body. Thus, they provide the opportunity not only for reconnecting with one's own rhythms, and for reconstructing a disrupted expectation system within an improvisation, but also for finding agency in the playful thwarting of expectations, and for exploring the continuum of separation and connectedness in a musical relationship. In this sense, music acts as a transitional phenomenon, creating an intermediate space between inner and outer worlds. In this "third" area of experiencing, both participants align with patterns that go beyond the sum of their contributions; when this state of flow is reached, one can feel that one is played by the music as much as one is playing it. The results of this study indicate that a close rhythmic analysis of improvised interactions can help music therapists to assess the client's level of trauma as well as to tailor interventions to move them out of the repetitious rhythms of hyper- and hypoarousal. For verbal psychotherapists and psychoanalysts, the implication is that rhythmically aware, embodied listening can open up new dimensions of transference and countertransference phenomena. To this end, clinicians should pay special attention to rhythmic shifts in affect, speech, and bodily gestures.

  • EVALUATING THE INFLUENCE OF DAUBERT'S CROSS-EXAMINATION SAFEGUARD ON ATTORNEYS' AND JURORS' JUDGMENTS ABOUT SCIENTIFIC EVIDENCE

    Author:
    Jacqueline Austin
    Year of Dissertation:
    2013
    Program:
    Psychology
    Advisor:
    Margaret Kovera
    Abstract:

    The Supreme Court's decision in Daubert v. Merrell Dow Pharmaceuticals, Inc clarified that federal trial judges were to serve as evidentiary gatekeepers for scientific evidence, evaluating scientific reliability when determining admissibility. When judges fail at gatekeeping and admit unreliable expert testimony, the Court expresses faith in the ability of cross-examination to reveal the reliability of testimony for jurors. For cross-examination to function as the Court intends, attorneys must recognize scientific flaws and craft cross-examination questions that expose scientific threats. Moreover, these scientifically informed cross-examinations must act as a form of scientific training for jurors. I conducted two studies to empirically examine the Court's assumptions regarding cross-examination. In Study One, 95 attorneys read a trial summary that contained expert testimony regarding an intelligence test. I varied the validity (presence v. absence of experimenter bias threat) and reliability (moderate v. high reliability indices on test-retest, inter-observer, and internal consistency scores) of the intelligence test. Attorneys provided lower ratings of scientific quality when the test was unreliable but did not craft cross-examination questions designed to expose the low reliability indices of the scientific test. Attorneys did not provide lower ratings of scientific quality when the intelligence test was invalid; however, a proportion of attorneys did craft cross-examination questions to expose the validity threat. In Study Two, I again varied the reliability and validity of the intelligence test and whether the cross-examination educated jurors about the study's flaws (scientifically informed vs. naïve). Either a judge or an attorney conducted the scientifically informed cross-examinations. Scientifically informed cross-examinations did not assist jurors with evaluating scientific reliability or validity. These studies suggest that cross-examinations may not function as a safeguard against flawed scientific evidence. Although some attorneys may be able to meet the Court's expectations, cross-examination may be an ineffective method of providing methodological training for jurors.

  • Attention shapes our expectations and perceptions: The neural mechanisms of top-down attention during adulthood and development

    Author:
    Snigdha Banerjee
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    John Foxe
    Abstract:

    Top-down attention is the focusing of attention at one's will through knowledge regarding a current task. There is evidence that top-down attention involves the modulation of sensory cortices by higher order regions. However, the mechanisms of top-down attention across sensory modalities, its influence on early sensory inputs, as well as interactions with motivational systems remain unclear. We performed the following set of electrophysiological experiments in typically developed adults and adolescents to examine these areas. 1) The supramodal attentional theory holds that parietally-based attentional mechanisms are shared across sensory modalities. We tested the supramodal theory by examining if lateralized parieto-occipital alpha-band activity, an established metric of top-down spatial attention, was observed in an audiospatial and visuospatial task. In support of the supramodal theory, we observed similar anticipatory alpha-band processes across auditory and visual tasks, but we also found an interaction of supramodal and sensory-specific attentional control processes. 2) There is evidence that top-down attention influences information immediately upon its arrival to sensory cortices, although there is debate in this area. In the current work, volitionally-driven top-down attention was engaged toward one of several overlapping surfaces in an illusion, in which the perceived brightness of the attended surface was enhanced. We observed the attentional enhancement of early visual evoked potentials, indicating that top-down attention shapes the earliest activations in visual cortices. 3) It is well known that motivation impacts attention, but the neural bases of these interactions remain unclear. We examined how level of interest in stimuli influenced top-down spatial attention mechanisms in typically-developing adolescents. Motivation enhanced established attentional processes during the anticipation of high vs. low interest stimuli, but also independently influenced frontal and parieto-occipital activations. These findings provide potential implications to inform clinical measures to improve impaired attentional processes in clinical populations (e.g. individuals with autism spectrum disorders). In sum, these studies revealed the powerful influence of top-down attentional control and its interacting systems on neural activations through several stages of anticipatory and post-stimulus processing during development and adulthood.

  • An Examination of Predictive Variables of Success in Mental Health Diversion Programs.

    Author:
    Virginia Barber Rioja
    Year of Dissertation:
    2009
    Program:
    Psychology
    Advisor:
    Thomas Kucharski
    Abstract:

    Diversion programs were developed to ease the overrepresentation of individuals with psychiatric disorders in the criminal justice system. These programs divert individuals with mental illnesses out of jails into community treatment. Despite the increased popularity of these programs, little is known about the psychosocial, psychiatric and psychological characteristics of the diverted individuals. In addition, despite the importance of using standardized assessment instruments pre-diversion, no published study has attempted to evaluate the utility of risk assessment instruments or measures of malingering, personality or psychopathology in diverted offenders. This investigation attempted to address this gap in the literature through three different studies that (1) described a sample of 61 defendants released from jail in terms of demographical, clinical, and criminological characteristics; (2) determined the utility of the HCR-20 violence risk assessment scheme and the Psychopathy Checklist: Screening Version (PCL: SV) in the prediction of diversion non-compliance, and recidivism in a sample of 120 defendants, and (3) identified alternative factors that help defendants succeed in diversion through a multiple case-study design. Results revealed that this sample consisted primarily of minority male defendants with extensive histories of prior arrests, significant histories of physical abuse, homelessness and suicidality, and co-morbid substance abuse and psychiatric disorders. The findings provided preliminary validation of the predictive validity of the HCR-20 and PCL: SV with defendants diverted to community treatment. The HCR-20 was found to be superior to the PCL: SV in predicting both non-compliance and recidivism, and the PCL: SV proved to be more useful in predicting recidivism than non-compliance. Results of multiple case-studies found a pattern of characteristics shared by participants who failed diversion regardless of HCR-20 results. These variables included history of physical abuse, family history of substance abuse or criminal behavior, levels of social support, and level of responsibility taken for the instant offence.

  • An Examination of Predictive Variables of Success in Mental Health Diversion Programs.

    Author:
    Virginia Barber Rioja
    Year of Dissertation:
    2009
    Program:
    Psychology
    Advisor:
    Thomas Kucharski
    Abstract:

    Diversion programs were developed to ease the overrepresentation of individuals with psychiatric disorders in the criminal justice system. These programs divert individuals with mental illnesses out of jails into community treatment. Despite the increased popularity of these programs, little is known about the psychosocial, psychiatric and psychological characteristics of the diverted individuals. In addition, despite the importance of using standardized assessment instruments pre-diversion, no published study has attempted to evaluate the utility of risk assessment instruments or measures of malingering, personality or psychopathology in diverted offenders. This investigation attempted to address this gap in the literature through three different studies that (1) described a sample of 61 defendants released from jail in terms of demographical, clinical, and criminological characteristics; (2) determined the utility of the HCR-20 violence risk assessment scheme and the Psychopathy Checklist: Screening Version (PCL: SV) in the prediction of diversion non-compliance, and recidivism in a sample of 120 defendants, and (3) identified alternative factors that help defendants succeed in diversion through a multiple case-study design. Results revealed that this sample consisted primarily of minority male defendants with extensive histories of prior arrests, significant histories of physical abuse, homelessness and suicidality, and co-morbid substance abuse and psychiatric disorders. The findings provided preliminary validation of the predictive validity of the HCR-20 and PCL: SV with defendants diverted to community treatment. The HCR-20 was found to be superior to the PCL: SV in predicting both non-compliance and recidivism, and the PCL: SV proved to be more useful in predicting recidivism than non-compliance. Results of multiple case-studies found a pattern of characteristics shared by participants who failed diversion regardless of HCR-20 results. These variables included history of physical abuse, family history of substance abuse or criminal behavior, levels of social support, and level of responsibility taken for the instant offence.

  • The Role of Sleep in Odor Memory Consolidation Within the Piriform Cortex

    Author:
    Dylan Barnes
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    Donald Wilson
    Abstract:

    Sleep is important for memory consolidation. One potential mechanism of memory consolidation is replay, where recently formed memories are repeated during post-learning sleep. For example, the firing sequences evoked in hippocampus during learning are spontaneously replayed during bouts of slow wave sleep (SWS). The phenomenon of replay during SWS is common in many neocortical systems. Odor memory may also rely on sleep-dependent consolidation, even though olfaction is not a neocortical system. The primary olfactory (piriform) cortex is a three-layered archicortex receiving direct input from the olfactory bulb. Piriform cortical activity during slow-wave sleep-like states is modified by recent odor experiences and becomes highly coherent with the amygdala and hippocampus, suggesting a possibility of replay in the olfactory system. The goal of this research was to describe the role post-training sleep had in odor memory consolidation. The initial study utilized two different types of conditioning: standard odor fear conditioning and differential fear conditioning to examine how olfactory training can affect perceptual odor discrimination. Results from this study showed that animals that undergo differential odor fear conditioning are better able to discriminate similar odors following conditioning compared to animals that undergo standard conditioning. Furthermore, this change in perception is possible through changes in the receptive fields of individual units within the piriform cortex. The next study examined how SWS in the anterior piriform cortex is involved in olfactory memory consolidation following odor fear conditioning. The amount of time animals spent in SWS following conditioning significantly increased compared to baseline habituation days and the amount of time animals spent in SWS following learning predicted how much time they froze to the odor during testing. Finally, the last study assessed changes in both the strength and precision of olfactory memory following modifications made during post-training SWS. Imposing replay of the learned odor during post-training SWS enhanced the strength of the odor memory, while imposing replay of another odor stimulus caused animals to generalize their fear response to multiple olfactory stimuli. Taken together, these results underlie the importance of sleep in the consolidation of both the strength and precision of odor memory.

  • MINORITIES' PERCEPTIONS OF MINORITY-WHITE BIRACIALS: THE ROLE OF IDENTIFICATION FOR COGNITIVE, AFFECTIVE, AND BEHAVIORAL RESPONSES

    Author:
    Sabrica Barnett
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    Daryl Wout
    Abstract:

    Research on intergroup relations has a rich history in social psychology, with scholars devoting a considerable effort investigating factors that influence stereotyping, prejudice and discriminatory behavior. The results of these studies suggest that individuals' cognitions, affect, and behaviors are affected by their own group memberships as well as the groups to which others belong. People generally view the groups that they belong to (their ingroup) positively, and view the groups that others belong to (outgroups) stereotypically (Tajfel & Turner, 1986). However, much of the research on social identification and subsequent perceptions has focused on socially distinct groups rather than groups that blur categorical boundaries. As such, there is a dearth of research on how individuals identify with and perceive people who belong to multiple racial groups. To address this gap in the literature, I investigated minorities' identification with minority-White biracials, as well as the downstream cognitive (warmth and competence stereotypes), affective (pride, shame), and behavioral (facilitation, distancing) consequences of identification across three studies. Results demonstrated that Black (Study 1) and Hispanic (Study 2) participants were equally identified with biracials and other ingroup members (Blacks, Hispanics), and were less identified with outgroup members (Whites). In contrast, White participants (Study 1) were most identified with other White people, least identified with Black people, and moderately identified with Black-White biracial people. Moreover, Black participants stereotyped Blacks and Black-White biracials as equally warm and competent (Study 1); Hispanic participants felt equally proud of and were equally willing to help Hispanics and Hispanic-White biracials (Study 2); and both Black and Hispanic participants felt equally ashamed when a Black or Hispanic and Black-White or Hispanic-White biracial person acted in a stereotypically negative manner, and wanted to distance themselves from the wrongdoer (Study 3). In contrast, minorities perceived Whites less positively across measures of stereotypes, emotions and behaviors. Finally, consistent with self-categorization theory (Turner et al., 1987), minorities' identification with minority-White biracials predicted their group-based stereotypes, emotions and behaviors. These results make an important contribution to the limited work on perceptions of biracial people, and extend previous research regarding the role of identification for intergroup perceptions.

  • Components of Emotional Experience and Reaction Time: A study of Normal Aging and Parkinson's Disease

    Author:
    Judy Barry
    Year of Dissertation:
    2013
    Program:
    Psychology
    Advisor:
    Joan Borod
    Abstract:

    We examined whether valence or arousal levels affect decision and movement times in Parkinson's disease (PD) and in healthy aging. For both decision and movement time, we were interested in differences in the speed and variability in responding. We also studied whether emotional experience is altered as a result of the aging process and PD pathology. Participants included 16 young healthy adults, 15 older healthy adults, and 15 non-demented individuals with mild PD. The PD participants were tested on medication. Participants viewed pictures from the International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2001) differing in emotional content and performed self-report valence and arousal ratings during picture presentation. Components of reaction time (i.e., decision time [DT] and movement time [MT]) were assessed during a forced-choice reaction time task. Results demonstrated that DT and MT were differentially affected by emotional stimuli. The PD group demonstrated significantly longer and more variable DTs than did the healthy controls for negative, positive, and neutral pictures; however, only the MTs for negative and neutral images were significantly different or more variable between groups. Although DTs were longer for the older control group relative to the younger control group, MTs were equivalent between the two control groups. Evidence of altered emotional experience in PD was found, as the PD participants rated negative pictures as less negative than did healthy older adults; however, this significant difference was reduced to a trend when individuals with more severe depressive symptomatology were excluded from the analysis. In addition, high arousal images were rated as more highly arousing among the PD group when depressed individuals were not included in the analyses. There was no evidence of impaired emotional experience as a function of aging, as valence and arousal ratings were not significantly different between younger and older adults. Better understanding of emotional processing deficits, which have been associated with poorer quality of life, in healthy aging and PD may lead to a better understanding of the neural bases of emotional processing, as well as offer treatment approaches.