To explore the subtypes of cognitive processing deficits in children with developmental dyslexia, this study administered phonological awareness, rapid automatized naming, phonological memory, orthographic processing, and visual processing tasks to children with developmental dyslexia and chronologically age-matched controls. Data were analyzed using analysis of variance and standard deviation cutoff methods. The results revealed that Chinese children with developmental dyslexia exhibited multiple subtypes of cognitive processing deficits. Among these, the prevalence of rapid automatized naming deficits was the highest, followed by phonological awareness deficits and visual processing deficits, while phonological memory and orthographic deficits were less common. In mixed deficits, the co-occurrence of visual processing, phonological awareness, and rapid automatized naming deficits showed relatively high stability. Notably, no pure visual processing deficit subtype was identified, as visual deficits always co-occurred with other deficits. Additionally, 34% of dyslexic children in this sample did not meet the deficit criteria on any cognitive task and were classified as a“ mild cognitive delay” group, who could not be assigned to any established subtype. These findings indicate that current classification frameworks based on single cognitive deficit thresholds fail to capture all children with dyslexia. Further validation with a larger sample is warranted.
