Contrasting Deficits in the Function of the Phonological Loop Between Children With Attention Deficit Hyperactivity Disorder and Reading Disability

Attention Deficit Hyperactivity Disorder (ADHD) and reading disability (RD) often co-occur. Impairments in the phonological loop of working memory are central to RD, but it is unclear whether this is linked to ADHD, especially in Chinese reading. Two experiments were conducted with Chinese children aged 7 to 12 (Experiment 1, n = 65; Experiment 2, n = 60). Immediate and delayed recognition paradigms were used to assess phonological encoding and rehearsal. Both the RD-only and comorbid (ADHD + RD) groups performed worse than the control and ADHD-only groups in response time and accuracy. Notably, the comorbid group performed similarly to the RD-only group, indicating that phonological loop deficits in comorbid children are likely due to RD, not ADHD. This highlights phonological loop function as the key to distinguishing between ADHD and RD.