Eye movements and visual-attentional function in neurodiverse Chinese children: effects of character complexity

Reading Chinese characters places high demands on visual processing. Children with reading difficulties (RD) often show weaknesses in visual attention that may hinder character recognition. This study compared the eye movements of Chinese children with and without RD during a timed orthographic similarity judgment task involving simple and complex characters. Fourteen children with RD and 16 typically developing (TD) peers (aged 9-12 years, primary 4-6) in Hong Kong SAR participated. Accuracy, reaction time, and eye-movement measures (number of fixations, total fixation duration, number of saccades, and average saccade amplitude) were analyzed. While accuracy did not differ between groups, children with RD showed longer reaction times and distinct eye-movement patterns. Character complexity increased task difficulty for both groups, but the effects were more pronounced in the RD group. Importantly, reduced saccade amplitude was observed in children with RD even for simple characters, suggesting broader visual processing constraints. These findings highlight the elevated visual-cognitive demands of Chinese reading and support the utility of eye-tracking measures as sensitive indicators of reading difficulties.