Lack of Neuropsychological Deficits in Generalized Social Phobia

There are relatively few existing studies examining neuropsychological functioning in social phobia (SP), which collectively yield mixed results. Interpretation of results is further complicated by a number of methodological inconsistencies across studies, including the examination of neuropsychological domains in relative isolation from one another. The present study utilized a broader collection of neuropsychological tests to assess nine domains of functioning in 25 individuals diagnosed with generalized SP and 25 nonpsychiatric controls (NC). A mixed ANOVA revealed neither a significant group by domain interaction, nor a significant main effect of group. Furthermore, no significant group differences emerged between the SP and NC groups within each specific neuropsychological domain. These findings suggest that underlying neuropsychological deficits are not likely to account for the information processing biases observed in the empirical literature, and appear to be consistent with current theoretical models which argue for the specificity of these biases to social information

Latent Factor Modeling of Four Schizotypy Dimensions with Theory of Mind and Empathy

Preliminary evidence suggests that theory of mind and empathy relate differentially to factors of schizotypy. The current study assessed 686 undergraduate students and used structural equation modeling to examine links between a four-factor model of schizotypy with performance on measures of theory of mind (Reading the Mind in the Eyes Test [MIE]) and empathy (Interpersonal Reactivity Index [IRI]). Schizotypy was assessed using three self-report measures which were simultaneously entered into the model. Results revealed that the Negative factor of schizotypy showed a negative relationship with the Empathy factor, which was primarily driven by the Empathic Concern subscale of the IRI and the No Close Friends and Constricted Affect subscales of the Schizotypal Personality Questionnaire. These findings are consistent with a growing body of literature suggesting a relatively specific relationship between negative schizotypy and empathy, and are consistent with several previous studies that found no relationship between MIE performance and schizotypy

A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

A multilaboratory comparison of calibration accuracy and the performance of external references in analytical ultracentrifugation.

Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

Schizotypal Personality Disorder Or Prodromal Symptoms Of Schizophrenia?

Schizotypal personality disorder shares some attenuated phenotypic features with schizophrenia, but represents an independent syndrome. In contrast, prodromal symptoms of schizophrenia represent early warning signs of the impending onset of schizophrenia. Although these constructs are intended to reflect independent syndromes, self-report instruments measuring these constructs assess similar symptoms. It does not appear that existing research has examined the relative discriminant validity of screening instruments for these syndromes. A sample of 998 young adults (68% female; 73% Caucasian), within the age of risk for schizophrenia (ages 18-34; mean 20.4 ± 2.2), met validity criteria after completing online versions of the Abbreviated Schizotypal Personality Questionnaire (SPQ-B) and the 24-item Abbreviated Youth Psychosis at Risk Questionnaire (Y-PARQ-B). Based on clinical cut-off scores used in previous research, 5.2% were [only] considered at heightened risk for psychosis (potentially prodromal), 3.4% had [only] schizotypal personality features, and 2.9% met criteria for both constructs (75% of individuals meeting cutoff for one measure did not meet criteria for the other). Males and younger participants scored significantly higher on both measures. The total scores from the SPQ-B and Y-PARQ-B showed a significant positive correlation (rs = .66, p \u3c .001, R2 = .43); however, 57% of the variance was not shared between the measures. Of the three SPQ-B subscales, Cognitive-Perceptual showed the strongest correlation with Y-PARQ-B. Results suggest that the SPQ-B and Y-PARQ-B have moderate discriminate validity between the overlapping, yet distinct, constructs of schizotypal personality and heightened risk of developing psychosis (potentially prodromal). © 2005 Elsevier B.V. All rights reserved

Olfactory Identification Performance In Individuals With Psychometrically-Defined Schizotypy

While deficits in olfaction have been well documented in individuals with schizophrenia, less research has focused on olfactory identification performance in psychometrically-defined schizotypy. The Abbreviated Schizotypal Personality Questionnaire was used to define two groups of 26 individuals (62% female) reporting high and average levels of schizotypy. Overall group differences on the Brief Smell Identification Test did not approach statistical significance, and this finding did not differ within either sex. The findings may reflect either the abbreviated nature of the measures used, or a lack of reliable olfactory performance differences in schizotypy

The Effect Of Red Light On Backward Masking In Individuals With Psychometrically Defined Schizotypy

Introduction. Previous research has suggested that individuals with schizophrenia and their relatives show a change in backward masking performance with a red background that is in the opposite qualitative direction as that found in nonpsychiatric controls. The present study examines this effect in individuals with psychometrically defined schizotypy to explore the potential of this effect to be a useful new qualitative endophenotype for schizophrenia-spectrum traits. Methods. The Abbreviated Youth Psychosis At-Risk Questionnaire was used to screen a large number of undergraduates for schizotypy symptoms. A sample of 23 participants scoring high on this measure were compared to a sample of 26 controls on a location backward masking task that was presented on both red and green backgrounds. Results. Consistent with findings in patients with schizophrenia, the participants reporting a high number of schizotypy features showed a decrease in performance to the red (compared to green) background and the controls showed a nonsignificant increase in performance - although this finding was limited to the stimulus-onset asynchrony (SOA) value that approximated the SOA with the largest effect size in the previous schizophrenia study (69 ms). Conclusions. Although limited to one SOA, results extend earlier findings approximating this SOA to include a psychometrically defined schizotypy sample. © 2008 Psychology Press

A Preliminary Investigation On The Relationship Between Color-Word Stroop Task Performance And Delusion-Proneness In Nonpsychiatric Adults

The current study examined whether there is a relationship between the dimension of delusion-proneness and performance on the color-word Stroop task. As dysfunction in the anterior cingulate cortex (ACC) has been related to both Stroop task performance and the presence of delusions in various psychiatric populations, we hypothesized that impaired Stroop performance would relate to increased delusion-proneness in a nonpsychiatric sample. A total of 36 college students, representing a wide range of scores on a measure of delusion-proneness (Peters et al. Delusions Inventory-PDI-21), completed a computerized version of the classic color-word Stroop task. Results revealed a statistically significant positive correlation between the PDI-21 score and the Stroop effect. The pattern of results suggests that reduced efficiency of Stroop performance is related to increasing levels of delusion-proneness. This study appears to be the first to report this relationship across a continuum of delusion-proneness in a nonpsychiatric sample. This finding contributes to the cognitive neurobiological understanding of delusions and adds further support for the dimensional construct of propensity for delusions. © 2008 Elsevier Ireland Ltd. All rights reserved

The Personality Assessment Inventory In The Evaluation Of Multiple Channel Exposure Therapy

The National Comorbidity Survey (NCS) determined that the comorbidity rate of posttraumatic stress disorder (PTSD) with panic disorder is 7.3% for males and 12.6% for females. A 21-year-old female\u27s presenting symptoms corresponded to this dual diagnosis, with the addition of comorbid major depressive disorder. The Personality Assessment Inventory (PAI) was used as part of an initial comprehensive assessment battery. Treatment was provided over a period of 6 months, and multiple channel exposure therapy (MCET) was chosen as the primary treatment, as it has been shown to be a promising treatment for the comorbid presentation of PTSD with panic disorder. Upon completion of the MCET, the PAI was readministered as a posttreatment evaluation. The posttreatment PAI results indicated clinical improvement across all indices that initially suggested clinical problems. Results of this case study suggest that the PAI is sensitive to treatment gains from the MCET for the comorbid conditions of PTSD, panic disorder, and major depressive disorder

Relationships between dimensional factors of psychopathy and schizotypy

Existing research has suggested that comorbid psychopathy may explain one trajectory of violent behavior in a subset of individuals with schizophrenia. However, it remains unclear which specific traits and symptoms are responsible for this relationship and whether it is limited to clinical and/or forensic categories, or if it reflects a dimensional relationship found in the general population. Therefore, the aim of this study was to examine differential relationships between specific factors of psychopathy and schizotypy in a nonpsychiatric and nonforensic sample. 212 undergraduate students (50% female) completed the Schizotypal Personality Questionnaire (SPQ) and the Psychopathic Personality Inventory-Revised (PPI-R). Correlations revealed that the total SPQ score was positively related to the total PPI-R score and the Self-Centered Impulsivity factor, and negatively related to the Fearless Dominance factor. Self-Centered Impulsivity was positively related to all three SPQ factor scores, with the strongest relationship found with the Cognitive-Perceptual factor. In contrast, Fearless Dominance was negatively related to only the Interpersonal and Disorganized factors of the SPQ, with the strongest relationship found with the Interpersonal factor. Findings suggest that the comorbidity of schizotypy and the self-centered impulsivity aspect of psychopathy is not limited to extreme discrete populations, but exists in a more dimensional manner within a nonpsychiatric sample. In addition, it appears that schizotypy is negatively related to the fearless dominance aspect of psychopathy, which appears to be a novel finding. Results provide preliminary findings that may have implications for developing appropriate prediction, assessment, and treatment techniques for violent behavior in schizophrenia-spectrum disorders