Memory-guided saccades in Psychosis : Effects of Medication and Stimulus location

Smith, Ellie and Crawford, Trevor (2021) Memory-guided saccades in Psychosis : Effects of Medication and Stimulus location. Brain Sciences, 11 (8): 1071. ISSN 2076-3425

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Abstract

The memory-guided saccade task requires the remembrance of a peripheral target location, whilst inhibiting the urge to make a saccade ahead of an auditory cue. The literature has explored the endophenotypic deficits associated with differences in target laterality, but less is known about target amplitude. The data presented came from Crawford et al. (1995), employing a memory-guided saccade task among medicated and non-medicated patients with Schizophrenia (n=31, n=12), Bipolar Affective Disorder (n=12, n=17), and neurotypical controls (n=30). The cur-rent analyses explore the relationships between memory-guided saccades toward targets with different eccentricities (7.5 degs and 15degs), the discernible behaviour exhibited amongst diagnostic groups, and cohorts distinguished based on symptomatology. Saccade gain control and final eye position were reduced among medicated-schizophrenia patients. These metrics were lessened further among targets with greater amplitudes (15o), indicating greater deficit. The medicated cohort exhibited reduced gain control and final eye positions in both amplitudes compared to the non-medicated cohort, with deficits markedly observed in the furthest targets. No group differ-ences in symptomatology (positive and negative) were reported, however, greater deficit was ob-served toward the greatest amplitude. This suggests that within the memory-guided saccade paradigm, diagnostic classification is more prominent in characterising disparities in saccade performance than symptomatology.