Borderline and schizotypal personality constructs were compared as predictors of dissociation for 971 nonclinical university undergraduates who completed 11 self-report behavior inventories. Structural equation modeling and multiple regression were used to (a) test the hypothesis that the quantitative interaction of borderline and schizotypal constructs would be the strongest predictor of dissociation and (b) evaluate each construct alone as well as their additive effect for prediction of dissociation. The interaction hypothesis was rejected; the quantitative interaction was only a substantively trifling and statistically nonsignificant predictor of dissociation. In a commonality analysis, the additive borderline and schizotypal effect was equivalent to schizotypy alone and marginally larger than the borderline effect alone for the prediction of dissociation. However, all three effects separately were substantial predictors; thus, dissociation is an untenable discriminator for the borderline and schizotypal constructs. Finally, when schizotypy was compared directly to the borderline construct such that the common variance was distributed dependent upon comparative predictive power (i.e., beta weights), schizotypy was greatly superior to the borderline construct for dissociative predictability. Consequently, reconsideration of the existing paradigm that dissociation is more strongly associated with the borderline construct than with schizotypy is warranted. / Department of Psychological Science

Thesis (M.A.)--University of North Carolina at Greensboro, 2006. / Title from PDF title page screen. Advisor: Thomas R. Kwapil; submitted to the Dept. of Psychology. Includes bibliographical references (p. 38-46).

No description available.

Previous research suggests there are a number of variables that are associated with the expression of schizotypal personality disorder (SPD) symptoms. Such variables include childhood trauma, depression and anxiety, substance use, normal-range personality traits, ethnicity, and gender. However, research to date has not examined all of these variables in a single study to determine how they may be interrelated or differentially related to SPD symptom domains. Of particular interest is the association of these variables as explained by the diathesis-stress model. This study utilized a convenience sample of 298 undergraduate students to examine a continuous range of scores for symptoms of SPD and how the interrelation of biological factors such as gender and ethnicity and psychosocial factors and stressors such as childhood trauma and personality traits, specifically neuroticism and extroversion, influence the expression of SPD symptoms. It was predicted that anxiety, depression, stress, and childhood trauma would positively correlate to SPD symptoms. It was also hypothesized that neuroticism and substance use would positively correlate to schizotypal traits and extroversion would be negatively correlated to schizotypal traits as measured by the Schizotypal Personality Questionnaire-Brief. It was further hypothesized that psychosocial stressors would be moderated by the aforementioned biological factors.

Olfactory identification deficits have received recent attention as a potentially useful endophenotype for schizophrenia. Examination of this deficit in individuals with schizotypal personality features (SPF) offers an alternative approach to multiple confounds present when examining individuals with schizophrenia. The aim of the current study was to compare the relative sensitivity of performance on measures of olfaction identification and sustained attention to the presence of SPF. Twenty-six undergraduates were defined as having SPF based on scoring in the top 10% of the Abbreviated Schizotypal Personality Questionnaire (SPQ-B; mean age 19.6, SD = 1.1; 62% female). These individuals were compared to twenty-six controls (scoring lower than half a standard deviation above the mean; mean age 19.8, SD = 1.6; 62% female). All participants were administered the Schizotypal Personality Disorder (SPD) section of the Structured Clinical Interview for DSM IV Axis II Personality Disorders (SCID-II). In addition, participants were administered the Brief Smell Identification Test (B-SIT) and a six-minute degraded-stimuli Continuous Performance Test (CPT). Group differences in performance indices of the CPT did not approach statistical significance. Similarly, there were no statistically significant group differences for males or females in performance on the B-SIT. Correlational analyses examined cognitive performance with a dimension score derived by summing quantitative ratings from the SPD items on the SCID-II. The SPD dimension score showed a statistically significant positive correlation with several performance indices of the CPT, including omission errors (rs(52) = .51, p ≤ .001) and commission errors (rs(52) = .38, p ≤ .005). In contrast, the B-SIT scores were not correlated with the SPD dimension score for males or females. Contrary to our hypothesis, results from the current study suggest that olfactory identification deficits may not represent a robust endophenotype consistently found in samples with schizotypal personality features. With regard to sustained attention, our differential findings suggest that schizotypal traits may be more adequately assessed through an interview by trained clinicians who use clinical judgment to determine the presence of phenotypic aspects of SPD (e.g., SCID-II), rather than relying on self-report measures (e.g., SPQ-B). Implications as well as limitations and future directions of these findings are discussed.

Theories embedded within evolutionary neurobiology offer useful frameworks within which to understand cognitive impairment in schizophrenia (SCZ). The current research invokes the Dual Trends Theory (DTT), an evolutionary model that posits that neural architecture develops along two separate pathways: the dorsal ‘archicortical’ trend and the ventral ‘paleocortical’ trend. Although various lines of research converge to suggest that SCZ is associated with dorsal trend impairment in the context of relative ventral trend sparing, one persistent inconsistency exists. Specifically, individuals with SCZ routinely show impairment on tasks of action inhibition (AI; the ability to inhibit a pre-planned movement), a function routinely shown to be mediated by the inferior frontal gyrus, a key structure of the ventral trend. Here we argue that conventional tasks of AI conflate AI per se with response conflict (CON) demands, a function shown to be mediated by the anterior cingulate cortex, a key structure of the dorsal trend. We define CON as any aspect of a task that increases the difficulty of deciphering or interpreting the meaning of task stimuli (e.g., greater perceptual similarity between imperative task stimuli). The current research administered novel AI tasks in order to independently examine increases in CON and increases in the prepotency to respond to a pre-planned movement (PREP; considered a more fundamental measure of AI). Consistent with study hypotheses, individuals with Schizoprenia-spectrum disorders (specifically schizotypy) failed to show compensatory response time (RT) slowing when confronted with increasing CON demands yet showed proportional RTs, relative to healthy control participants, as PREP demands increased. These findings were interpreted as reflecting impairment in their ability to detect and/or decipher CON. More broadly, these findings suggest that cognitive abnormalities in SCZ may represent disproportionately impaired dorsal trend circuitry.

Theories embedded within evolutionary neurobiology offer useful frameworks within which to understand cognitive impairment in schizophrenia (SCZ). The current research invokes the Dual Trends Theory (DTT), an evolutionary model that posits that neural architecture develops along two separate pathways: the dorsal ‘archicortical’ trend and the ventral ‘paleocortical’ trend. Although various lines of research converge to suggest that SCZ is associated with dorsal trend impairment in the context of relative ventral trend sparing, one persistent inconsistency exists. Specifically, individuals with SCZ routinely show impairment on tasks of action inhibition (AI; the ability to inhibit a pre-planned movement), a function routinely shown to be mediated by the inferior frontal gyrus, a key structure of the ventral trend. Here we argue that conventional tasks of AI conflate AI per se with response conflict (CON) demands, a function shown to be mediated by the anterior cingulate cortex, a key structure of the dorsal trend. We define CON as any aspect of a task that increases the difficulty of deciphering or interpreting the meaning of task stimuli (e.g., greater perceptual similarity between imperative task stimuli). The current research administered novel AI tasks in order to independently examine increases in CON and increases in the prepotency to respond to a pre-planned movement (PREP; considered a more fundamental measure of AI). Consistent with study hypotheses, individuals with Schizoprenia-spectrum disorders (specifically schizotypy) failed to show compensatory response time (RT) slowing when confronted with increasing CON demands yet showed proportional RTs, relative to healthy control participants, as PREP demands increased. These findings were interpreted as reflecting impairment in their ability to detect and/or decipher CON. More broadly, these findings suggest that cognitive abnormalities in SCZ may represent disproportionately impaired dorsal trend circuitry.

The current study provides convergent, discriminant, and incremental validity data for a measure of schizotypia from the perspective of the Five-Factor Model (FFM) of general personality structure. Nine schizotypia facet scales were constructed as maladaptive variants of respective facets of the FFM (e.g., Aberrant Ideas as a maladaptive variant of FFM Openness to Ideas). On the basis of data from 143 undergraduates the convergent validity of these nine facet scales was tested with respect to 11 established measures of schizotypia and the respective facets of the FFM. Discriminant validity was tested with respect to other personality disorders and facets from other FFM domains. Incremental validity was tested with respect to the ability of the FFM schizotypia facet scales to account for variance in two established measures of schizotypia, after variance accounted for by respective FFM facets and other established measures of schizotypia were first removed. The findings support the validity of these new facet scales as measures of schizotypia and as maladaptive variants of the FFM.

Thesis (Ph. D.)--University of California, San Diego, 2007. / Title from first page of PDF file (viewed November 7, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Psychology, 2006. / Includes bibliographical references.