Social and Behavioral Sciences Commons^™

Stability Of Neurocognitive Abilities In Heterogeneous Subgroups Of Schizophrenia, Megan L. Becker Wright

UNLV Theses, Dissertations, Professional Papers, and Capstones

Considerable work has been devoted to characterizing the latent structure of cognition in schizophrenia (SZ) to understand important clinical outcomes associated with generalized or specific deficits but findings are limited in a number of ways. Previous work has not assessed bifactor and other complex models of cognition in SZ, which might provide a better understanding of the structure of cognitive abilities. It is also unclear whether the latent structure of cognitive abilities is similar between men and women with SZ or whether the latent structure of cognitive abilities is stable over time with repeated assessment. These limitations must be addressed …

Measures And Conceptualizations Of Symptoms In Schizophrenia, Nina B. Paul

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia presents as a heterogenous disorder characterized by diverse expression of symptoms between individuals. Thus, clinicians and researchers rely on comprehensive symptom measures for diagnosis and treatment. This dissertation investigated two symptom measures, the Positive and Negative Syndrome Scale (PANSS; Kay, Fiszbein, & Opler, 1987), a commonly used scale that assesses a broad range of symptoms of schizophrenia, as well as the Brief Negative Symptom Scale (BNSS; Kirkpatrick et al., 2011; Strauss et al., 2012), a novel scale that focuses on the assessment of five negative symptom domains (i.e., anhedonia, asociality, avolition, blunted affect, and alogia). The first study of …

Functional Capacity Profiles In Bipolar Disorder And Schizophrenia, Ashley Sara Emami

UNLV Theses, Dissertations, Professional Papers, and Capstones

Serious mental illnesses (SMIs) often have an onset early in life and go on to produce disability and functional impairment, which require ongoing supportive services and loss of productivity. Bipolar disorder (BD) and schizophrenia (SZ) are two of the most common SMIs. BD and SZ differ in their pattern of neurocognitive performance, which suggests differences in the severity of functional impairment between the illness groups. Within these psychiatric illness groups, subgroups may also be identified using cluster analysis. Evidence points to heterogeneity in functional outcomes in BD and SZ, yet very little research has assessed for subgroups based on functional …

Visual Attention And Emotion Regulation In Schizophrenia, Bern Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Emotion regulation and emotion processing deficits cut across the varying symptom presentations of schizophrenia. Emotion processing deficits are inadequately treated by pharmacologic interventions and are related to real-world functional impact and disability. This study investigated behavioral and psychophysiological responses to a series of emotion regulation tasks while concurrently collecting eye tracking data as an index of visual attention. A brief neurocognitive assessment was also completed in order to examine potential cognitive determinants of emotion. Participants completed tasks designed to assess cognitive change and directed attention strategies for down-regulation of unpleasant and pleasant emotion. For each of our two unpleasant emotion …

Face Affect Perception In Schizophrenia And Posttraumatic Stress Disorder, Lisa Beckman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia (SZ) and Posttraumatic Stress Disorder (PTSD) are often comorbid psychological disorders. Separately, research has previously demonstrated deficits in social cognition, including affect recognition impairment in both disorders; however, less is reliably known about the specific deficits unique to a comorbid diagnosis of SZ and PTSD. This study examined the ability to correctly identify facial expressions in individuals diagnosed with SZ (n = 38) and PTSD alone (n = 20), comorbid SZ and PTSD (n = 26), and healthy controls (n = 28). Participants were administered a test battery to establish diagnoses of of schizophrenia and PTSD, and to evaluate …

Development And Validation Of A Brief Assessment Of Social Cognitive Abilities, Ryanna Zenisek

UNLV Theses, Dissertations, Professional Papers, and Capstones

It has been consistently found that individuals with schizophrenia exhibit impairments across various social cognitive domains, including emotion processing, social perception, and theory of mind. These deficits have been found across illness stages and cannot be accounted for by clinical symptomatology or neurocognitive skills. Further, while it has been well established that there is a link between cognition and functional outcome, social cognition has been found to be uniquely related to functional impairment in the disorder. Despite this evidence, the field is currently lacking efficient ways to identify and characterize these deficits in clinical settings. The Brief Test of Social …

Understanding Stress Reactivity In Schizophrenia, Mary Vertinski

UNLV Theses, Dissertations, Professional Papers, and Capstones

The role of stress has long been recognized in schizophrenia; several theories have identified the role of stress as an important factor in the etiology of schizophrenia. A handful of studies have used laboratory psychosocial stressors to examine cortisol stress response in schizophrenia; the results obtained have consistently suggested that the stress response is attenuated in people with schizophrenia. Present study set out to examine stress responsivity in schizophrenia relative to healthy controls. A laboratory stress test was used to investigate cortisol response, heart rate and task appraisal in a sample of 17 healthy controls and 16 men diagnosed with …

Integration Of Audio-~Visual Emotional Information In Schizophrneia, Bern Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia (SZ) is a debilitating illness characterized by a number of perceptual and

cognitive deficits. Deficits in emotional judgment and perception are consistently identified, although less is known about the integration of emotional information from separate sensory modalities. This study investigates the integration of auditory and visual emotional information in schizophrenia and healthy controls through application of an emotion judgment task modeled after the McGurk effect. The emotional judgments of 54 participants (40 SZ and 14 control participants from the community) for auditory, visual, and bimodal phonemic stimuli conveying no lexical information were analyzed. Visual and auditory stimuli conveying joy …

Functional Capacity In Schizophrenia: Relationship Among Effort, Reinforcement Learning And Self-Beliefs, Sally J. Vogel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Individuals with schizophrenia exhibit a wide range of complex neurocognitive, psychiatric and behavioral impairments. Recent research suggests that this complex array of symptoms can be at least partially accounted for by dysfunction in more basic mechanisms, such as the ability to learn from positive and negative reinforcement, or the ability to exert adequate effort when completing simple tasks. Evidence also suggests that deficits in these basic mechanisms may contribute to more complex symptoms, such as functional impairment. Also, the relationship between neurocognitive deficits and functional impairment has been found to be mediated by defeatist performance beliefs. However, studies have not …

Impaired Theory Of Mind In Psychotic And Affective Disorders, Erik Nelson Ringdahl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Psychotic symptoms in bipolar I disorder during mood episodes has been associated with several negative outcomes raising the question as to whether psychosis is a risk factor for a more severe form of this chronic and debilitating condition. However, relatively little research has been directed at understanding the relationships among social cognitive functioning in bipolar I disorder with and without a history of psychosis. Impaired social cognition has been identified as a putative endophenotypic markers in schizophrenia and the evidence is mounting as to whether similar impairments also exist in bipolar I disorder. Given the plethora of research supporting the …

Auditory Processing Deficits In Bipolar Disorder With And Without A History Of Psychotic Features, Ryanna Verbiest

UNLV Theses, Dissertations, Professional Papers, and Capstones

Auditory perception deficits have been identified in schizophrenia and linked to dysfunction in primary auditory cortex. There is also evidence that primary auditory cortex abnormalities are associated with positive symptoms, particularly auditory hallucinations. Given the evidence that individuals with bipolar disorder frequently experience auditory hallucinations, it may be that individuals with bipolar disorder who also exhibit psychotic symptoms demonstrate similar impairment in auditory perception tasks. Additionally, these deficits may contribute to impaired social interactions, as they are likely to interfere with accurate perception of emotion from spoken words. The current study examined this matter by comparing performance of 50 individuals …

A Computational Perspective Of Schizophrenia, Ernesto H. Bedoy, Geoff Powell, Jefferson Kinney

McNair Poster Presentations

The etiology of schizophrenia remains largely elusive, thus dampening the effectiveness of current treatment strategies. Abnormal neural migration and neurogenesis in the hippocampus have been suggested to be involved in schizophrenia (Jakob & Beckmann, 1994). A few approaches, including computational modeling, have investigated schizophrenia as a network disorder. Computational modeling uses mathematics to predict the behavior of biological systems based on the input of a set of parameters collected from laboratory experiments. In this study, we constructed a computational model to explore the ramifications of additional PV neurons migrating to an aberrant location in the hippocampus and interfering with a …

Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia is a debilitating mental disorder that affects up to 3% of the world population. The behavioral symptoms are categorized into positive and negative symptoms, which appear during late adolescence/early adulthood. Unfortunately, the underlying cellular and molecular mechanisms of the disease are poorly understood. Several hypotheses exist to explain mechanisms contributing to these behavioral alterations. One model proposes that a reduced function of the NMDA glutamate receptor on specific GABAergic interneurons may be responsible for deficits in schizophrenia. Post-mortem investigations provide evidence of reductions in both glutamate and GABA-related proteins in patients with schizophrenia. Further, GABAergic interneurons that are activated …

Ketamine Induced Deficits In Working Memory With Relevance To Schizophrenia, Michael A. Langhardt, Jefferson Kinney

McNair Poster Presentations

Schizophrenia is a chronic debilitating brain disorder, which affects approximately one per­cent of the adult population worldwide. The symptoms of schizophrenia are commonly divided into three broad classes: positive symptoms, negative symptoms, and cognitive disturbances (Kay, et al., 1987). The positive symptoms of schizophrenia include hallucinations, delusions, and dis­organized thinking, while the negative symptoms include affective flattening, social withdrawal, and an inability to plan and carry out future activities. The cognitive disturbances exhibited in schizophrenia include deficits in spatial reference and working memory as well as difficulties with focus and attention (Lewis et. al., 2007). Several models have been proposed …

Affect Identification And Interpersonal Skills: An In-Depth Evaluation Of Social Cognition In Schizophrenia, Griffin Pollock Sutton

UNLV Theses, Dissertations, Professional Papers, and Capstones

The presence of deficits in various sub-domains of social cognition has been investigated to a degree in individuals with schizophrenia. Some of the most commonly researched and documented deficits have included impairments in the identification of affect portrayed in faces. Research has indicated that the performance of individuals with schizophrenia on such tasks is generally impaired as compared to normal controls. However, some have questioned the generalizability of such findings to real-world situations, as day-to-day interactions generally necessitate a constant, fluid assessment of the thoughts and feelings of others and are rarely, if ever, limited to still images of others. …

Using Negative Feedback To Guide Behavior: Impairments On The Wisconsin Card Sorting Test Relates To Psychosis, Sally Barney

UNLV Theses, Dissertations, Professional Papers, and Capstones

There is increasing controversy regarding the distinction between schizophrenia and bipolar disorder as separate diagnostic categories because these disorders share many features in common. These and other findings suggest that bipolar disorder and schizophrenia may be better conceptualized along a continuum or within more homogeneous subsets of affective, psychotic, and mixed symptomatology.

Dopamine dysregulation has been found in schizophrenia and bipolar disorder, particularly those that experience psychosis during the acute phases of their bipolar illness. Dopamine has been found to play a role in reward and reward learning. Recently, research has found that individuals with schizophrenia experience deficits in reward …