Influence of Salience on Neural Responses in Metaphor Processing of Chinese Children with Autism: Evidence from ERPs

This study, grounded in the Graded Salience Hypothesis (GSH), utilizes Event-Related Potentials (ERPs) to explore metaphor processing mechanisms in 24 Chinese children with Autism Spectrum Disorder (ASD) aged 5-12 years, compared with 37 age-matched typically developing (TD) peers. Employing a 2 (Group: ASD vs. TD) × 2 (Sentence Type: Metaphor vs. Literal) × 2 (Salience: High vs. Low) factorial design, we examined neural responses to 48 validated Chinese sentences (balanced for high/low-salience metaphor-literal sentence contrasts) while controlling lexical complexity and syntactic structure. Through linear mixed-effects modeling, the study reveals three key findings: (1) ASD children exhibited reduced P200 amplitudes (150-250 ms) for metaphors compared to literal sentences, indicating impaired early salience-driven attention; (2) Attenuated N400 responses (300-500 ms) to both sentence types in ASD versus TD groups, reflecting context-independent semantic integration deficits; (3) No group differences in Late Positive Component (LPC) (600-1000 ms), suggesting comparable late-stage pragmatic evaluation. These results provide the first neurophysiological evidence for GSH in ASD, demonstrating that salience gradients critically modulate early metaphor processing stages. The findings highlight developmental divergence in ASD children's reliance on salience-based prioritization, offering mechanistic insights for designing metaphor comprehension interventions tailored to salience hierarchies.