Visual Elements of Schizotypy Experiences: An Investigation of Representational Momentum and Eye-Tracking Risk Markers.

Eye tracking dysfunction including smooth pursuit and voluntary eye movement are the most robust biological markers for risk of schizophrenia. Researchers suggested that eye tracking impairment may also involve higher-order functions such as errors in the prediction of an object’s position, yet the relationship is unclear. Therefore, prediction of an object’s position was tested through a unique phenomenon observed in schizophrenia and those at risk coined the representational momentum (RM) effect. The aim of the current study was to determine whether the prediction of an object’s position is involved in eye movement anomalies and to what extent eye tracking and prediction is differently related to aspects of schizotypy. It was hypothesised that a) the eye tracking indices would be differently related to schizotypy subtypes, and b) the RM effect would significantly contribute to a model predicting risk for schizophrenia. One hundred and seventy-one participants were assessed on evidence-based eye tracking tasks that measured pursuit gain, the visual grasp reflex (VGR), and a RM task. These measures were combined to provide a model that could predict psychometric risk of schizotypy, using the Schizotypal Personality Questionnaire (SPQ). Each of the eye tracking measures were differently related to risk, but, together as a model they were not able to determine risk. More specifically, RM did not significantly contribute to the prediction of risk when it was added to a multiple regression model. Although the results were not consistent with all the current study’s hypotheses, there were positive initiatives for the RM and eye tracking. It was concluded that the RM effect has the potential to improve the understanding of eye tracking dysfunction in schizophrenia. However, future research needs to be carried out to better understand the role of RM

Visual Elements of Schizotypy Experiences: An Investigation of Representational Momentum and Eye-Tracking Risk Markers.

Eye tracking dysfunction including smooth pursuit and voluntary eye movement are the most robust biological markers for risk of schizophrenia. Researchers suggested that eye tracking impairment may also involve higher-order functions such as errors in the prediction of an object’s position, yet the relationship is unclear. Therefore, prediction of an object’s position was tested through a unique phenomenon observed in schizophrenia and those at risk coined the representational momentum (RM) effect. The aim of the current study was to determine whether the prediction of an object’s position is involved in eye movement anomalies and to what extent eye tracking and prediction is differently related to aspects of schizotypy. It was hypothesised that a) the eye tracking indices would be differently related to schizotypy subtypes, and b) the RM effect would significantly contribute to a model predicting risk for schizophrenia. One hundred and seventy-one participants were assessed on evidence-based eye tracking tasks that measured pursuit gain, the visual grasp reflex (VGR), and a RM task. These measures were combined to provide a model that could predict psychometric risk of schizotypy, using the Schizotypal Personality Questionnaire (SPQ). Each of the eye tracking measures were differently related to risk, but, together as a model they were not able to determine risk. More specifically, RM did not significantly contribute to the prediction of risk when it was added to a multiple regression model. Although the results were not consistent with all the current study’s hypotheses, there were positive initiatives for the RM and eye tracking. It was concluded that the RM effect has the potential to improve the understanding of eye tracking dysfunction in schizophrenia. However, future research needs to be carried out to better understand the role of RM

Logistic regression analyses of cardiac biomarkers for 30-day mortality.

*<p>PSI = Pneumonia Severity Index.</p><p>Age-adjusted analyses analysed NT-proBNP and Troponin T separately with adjustment for patient age. Multiple-adjusted analyses include both biomarkers and the Pneumonia Severity Index class in the same model. High NT-proBNP and Troponin T are defined as >220 pmol/L and >50 ng/L respectively.</p

1 year Kaplan-Meier survival curve for patients following community-acquired pneumonia stratified according to NT-proBNP level.

<p>Survival was worse in patients with high NT-proBNP levels (>220 pmol/L) compared to patients with normal NT-proBNP levels (≤220 pmol/L) (log-rank test, p<0.0001).</p

Receiver operating characteristic (ROC) curve for NT-proBNP and Pneumonia Severity Index class in 30-day mortality prediction.

<p>The area under the ROC curve = 0.8803 for NT-proBNP and 0.8701 for Pneumonia Severity Index class respectively.</p

Cohort Characteristics.

<p>Differences between patients who died and those who survived were assessed by chi-squared for categorical data and Wilcoxon rank-sum tests for continuous data. IQR = inter quartile range.</p

30-day mortality according to biomarker levels on admission.

<p>Mortality was lower in patients with normal NT-proBNP and Troponin T levels than patients with elevated NT-proBNP alone (9/86, p = 0.0002) and both elevated NT-proBNP and Troponin T (14/62, p<0.0001).</p