| Abstrakt: |
Background: Visual attention in Schizophrenia (SZ) differs from that of neuro-typical controls, and scan-path abnormalities have been proposed as a robust marker of the disorder (Nishiura et al., 2007). In free viewing paradigms, a restricted area of visual exploration has been reported as a robust atypical finding in SZ participants across a variety of depicted contents (Beedie et al., 2011), and has been shown to be a highly efficient discriminator between SZ and healthy controls (Benson et al., 2012). Moreover, speaking about what one sees during the act of looking has been shown to impact visual exploration behavior (Klein et al., 2014). Finally, despite clinical and genetic-biological relationships between schizophrenia, autism and ADHD (Owen & O’Donovan, 2017) there is, to our knowledge, yet no direct comparison between these neurodevelopmental disorders using eye tracking. The “head-to-head” comparison is the primary objective of this study. Methods: We tested four groups of adolescent and young adults, namely early-onset Schizophrenia (SZ, N=21, 15 males, mean age ± 1 standard deviation 19.7±1.7 years), Attention Deficit Hyperactivity Disorder (ADHD, N=28, 15 males, 19.9±1.4 years), Autism (ASD, N=26, 25 males, 19.7±1.9 years), and typical controls (TD, N= 29, 12 males, 19.8±1.6 years). The ocular-motor task battery comprised of different free viewing tasks including free viewing of different kinds of social interactions in static pictures whilst solely viewing versus viewing-plus speaking (in counterbalanced order). Eye movements were recorded with 1.000Hz using the EyeLink 1000+ system and analyzed with Data Viewer Eyelink Software and MATLAB (Version R2017a, Mathworks, USA). Statistical Analysis was performed in SPSS Statistics 2.3 (IBM, USA). Results: Visual attention of SZ patients manifested significant less gaze scatter than TD whilst merely looking at the images. During looking and speaking, however, the two groups had a similar spatial scatter of fixations. Preliminary analyses indicate that participants with ADHD and ASD did not differ from TD in this measure. Discussion: Constraint gaze scatter in visual exploration is a robust and discriminating finding in schizophrenia that has been associated with the negative symptomatology of the disorder. The present results confirm our previous findings (Klein et al., 2014) and suggest that the act of speaking may partially counteract and compensate the restricted visual scanning performed by SZ participants, thus contributing to a better understanding of Visual Attention in SZ and its differentiation from other neurodevelopmental disorders. [ABSTRACT FROM AUTHOR] |
