Smooth pursuit eye movements in 1,087 men: effects of schizotypy, anxiety, and depression

Abstract

Individuals with schizotypal personality disorder or high scores in questionnaires measuring schizotypy are at high risk for the development of schizophrenia and they also share some of the same phenotypic characteristics such as eye-tracking dysfunction (ETD). The question arises whether these individuals form a distinct high-risk group in the general population or whether schizotypy and ETD co-vary in the general population with no distinct cutoff point for a high-risk group. A large sample of military conscripts aged 18-25 were screened using oculomotor, cognitive and psychometric tools for the purposes of a prospective study on predisposing factors for the development of psychosis. Schizotypy measured using the perceptual aberration scale (PAS) and the schizotypal personality questionnaire (SPQ), anxiety and depression, measured using the Symptom Checklist 90-R, had no effect on pursuit performance in the total sample. Small groups of individuals with very high scores in schizotypy questionnaires were then identified. These groups were not mutually exclusive. The high PAS group had higher root-mean-square error scores (a quantitative measure for pursuit quality) than the total sample, and the high disorganized factor of SPQ group had lower gain and higher saccade frequencies in pursuit than the total sample. The presence of significant differences in pursuit performance only for predefined high schizotypy groups favors the hypothesis that individuals with high schizotypy might present one or more high-risk groups, distinct from the general population, that are prone to ETD as that observed in schizophrenia.

Smooth Pursuit and Visual Occlusion: Active Inference and Oculomotor Control in Schizophrenia

“…Interestingly, the relatives' peak predictive gain was also significantly poorer, irrespective of whether they were schizotypal or not. Similar results were obtained from a large community subject sample, in which all schizotypal individuals (disorganized subtype) had significantly lower residual predictive gain [36], whereas only the high-scoring (>2SD) disorganized schizotypal subjects had diminished maintenance gain [37].…”

Vergence eye movements in patients with schizophrenia

“…We observed, as others have (Cerbone et al, 2003; Ettinger et al, 2003; Hong et al, 2005; Hutton et al, 2001; Smyrnis et al, 2007; Sweeney et al, 1998), that the smooth pursuit gain deficit was dependent on target velocity and that the difference between the schizophrenia group and healthy controls grew as velocity increased. Similarly, vergence tracking gain was dependent on target velocity and the difference between the groups increased as target velocity increased.…”

The effects of ketamine and risperidone on eye movement control in healthy volunteers

“…10,11 The use of eye movements in this approach is supported by findings that oculomotor performance is impaired in schizophrenia patients, schizotypal personality and in psychometric schizotypy, thus representing neural abnormalities underlying the schizophrenia spectrum. 12, 13, 14, 15, 16 The well-known neural correlates, high reliability and simple application of oculomotor paradigms make them ideally suited to study pharmacological effects in healthy volunteers and patient populations. 10 The most commonly studied procedures include prosaccades (PS), a simple measure of stimulus-driven overt attentional shifts, which often provides a useful baseline condition, 17 antisaccades (AS), a measure of the integrity of volitional control of behaviour (for review see Hutton and Ettinger 2006 13 ) and smooth pursuit eye movements (SPEM), measuring attentional and motion processing functions.…”