Eye-Movement Intervention for Cognitive Impairment Across Schizophrenia Spectrum

This study is a stratified, randomized, active-controlled, assessor-blinded clinical trial designed to evaluate the effects of a gamified eye-movement intervention on cognitive function across the schizophrenia spectrum, including clinical high-risk individuals, first-episode schizophrenia patients, chronic schizophrenia patients, and healthy controls. Cognitive impairment is a core feature of schizophrenia-spectrum disorders and is associated with poor functional outcomes across illness stages. Eye movements are closely linked to cognitive processes such as attention, working memory, and executive control, suggesting that eye-movement-based training may have potential as a cognitive intervention. Participants will be stratified by illness stage and randomly assigned in a 1:1 ratio to either an eye-movement intervention group or an active control group receiving matched finger-controlled game training. The intervention targets core oculomotor functions, including fixation control, smooth pursuit, and saccadic eye movements, through structured gamified training tasks. The intervention lasts 4 weeks, with 3-4 sessions per week. The primary outcome is change in cognitive performance assessed using the MATRICS Consensus Cognitive Battery (MCCB), including composite and domain-specific T-scores from baseline to week 4. Secondary outcomes include changes in oculomotor functions and visual exploration patterns assessed using standardized eye-tracking tasks, including fixation stability, smooth pursuit, antisaccade, and free-viewing paradigms. Clinical symptom severity will be assessed using the Scale of Psychosis-Risk Symptoms (SOPS) for clinical high-risk participants and the Positive and Negative Syndrome Scale (PANSS) for schizophrenia participants. Statistical analyses will evaluate intervention effects on cognitive, eye-movement, and clinical outcomes, including group-by-time interactions across illness stages.