Abstract
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.