Bright Lights, Silent Signals: Colour-Specific Attention–Arousal Decoupling in Autistic Children Revealed by Eye-Tracking and Pupillometry

Abstract

Purpose: Atypical visual exploration is widely reported in autism spectrum disorder (ASD), yet little is known about how chromatic properties modulate oculomotor behaviour. This study aims to address this problem. Methods: We recorded eye movements from 34 children with ASD (6–16 y) and 40 age-matched typically developing (TD) peers while they viewed six picture sets that independently manipulated hue, luminance and saturation. Nine eye-movement metrics were extracted per task and analysed with mixed-effects ANOVAs; false-discovery-rate control (q =.05) and Holm–Bonferroni corrections were applied across 54 planned tests. Results: Across all tasks, the ASD group showed a 29% reduction in total fixation time (F = 11.13, q