A semantic processing development study in 7-11 years old children with attention deficit hyperactivity disorder and normal children: an ERP study of N400

Objective To explore the developmental characteristics of semantic processing of children with attention deficit hyperactivity disorder(ADHD) by comparing the event related potential in normal children and ADHD children (ages 7-11 years old). Methods 83 ADHD children and 93 normal children ranging from 7 to 11-year were divided into 5 groups to analyze the difference of the amplitude and latency of ERP N400 in three conditions: the related, unrelated and pesudoword after the Chinese character word visual stimulus task. Results (1)The related condition: the amplitude of the 7 years old normal children group was higher than 11 years old((-10.67±4.39)μV, (-4.62±3.55)μV; P=0.005); and the amplitude was highest in 8 years old group in children with ADHD((-10.77±6.66)ms, F=2.54, P=0.046). The latency in normal children was shorter at 8 years old((311.7±33.1)ms, P<0.05), but was shorter at 9 years old in ADHD group.(2)The unrelated condition: the amplitude of normal children aged 10 years was higher than that of other age groups.(3)The pesudoword condition: the amplitude of 9 years old normal children was higher than other age groups. The amplitude of ADHD in children aged 9 years was higher than that in other age groups((-16.08±7.14)μV, P<0.05). Conclusion In the semantic related conditions, the amplitude of the N400 in ADHD children at the age of 8 and the latency at the age of 9 are significantly developed, and in the false words conditions, it is at the age of 11. This suggests that the ability of 7-11 years old ADHD children's orthographic semantic processing and cognitive development are slower than normal. N400 can better reflect the children's early language cognitive ability, and it is valuable for the early diagnosis of children with ADHD. Key words: Attention deficit hyperactivity disorder(ADHD); Children; N400, Event velated potenttal; Semantic Processing; Development