Lettie Wareing
The negative symptoms (NS) of schizophrenia can predate the onset of psychosis and are associated with poor functional outcomes; therefore, detecting their presence can facilitate early intervention. However, NS lack both understanding and sensitive, objective diagnostic tools. Saccadic eye movement paradigms objectively measure cognitive functioning and enable its localisation within the brain. To further the current understanding of NS, this study measured the performance of positive and negative symptom groups on the memory-guided saccade task. Additionally, it sought to determine the effects of antipsychotic medication on memory-guided saccade performance. A secondary dataset originally collected by Crawford et al. (1995) was used for these analyses. Supporting the study’s hypotheses, medicated individuals with SZ (n = 40) showed hypometric gain and gain of final eye position compared to unmedicated individuals (n = 18) and healthy controls (n = 31). Error rate was elevated in both patient groups relative to controls. Furthermore, NS scores were a significant predictor of error rate. However, contrasting with predictions, NS did not predict latency. Results suggest that elevated error rate on the memory-guided saccades has potential as an endophenotype of NS. Moreover, findings evidence the confounding effect of antipsychotic medication on memory-guided saccade performance in schizophrenia.