Studies In The Event-related Potentials (N400) Of Patients With Attention Deficit Hyperactivity Disorder

Objective:Event-related potentials refers to when people do a cognitive processing of stimuli from the surface of the head and recording the brain potential, which reflects the neurophysiological changes of brain in cognitive processes. Integrated visual and auditory continuous performance test is a neuropsychological measurement tools to evaluate the attention-based function to assess the subjects who implement the same task in auditory and visual attention function. The purpose of this study is to try to analysis the event-related potential N400 of children with attention deficit hyperactivity disorder and the correlation between N400 and IVA-CPT to explore the impacts of ADHD on children’s verbal thinking development.Methods:In this study,30 cases outpatient diagnosed by the American fourth edition of the diagnostic and statistical Mannual of Mental Disorders (DSM-IV) in attention deficit hyperactivity disorder diagnosis children standards and 30 healthy volunteers whose age is matched as controls to do the IVA-CPT test. While using visual Oddball paradigm, recording amplitude, latency and the area under the amplitude in the area of F3, F4, Cz, P3, P4 of event-related potentials N400, Then to do a statistic on the correlation between the parameters of N400 and IVA-CPT.Results:We found that, children with ADHD and three subtypes compared with healthy volunteers, the amplitude of N400 of ADHD is reduced (P<0.05) and the latency is extended,particularly in Cz (central region), F3 (left frontal region) and P3 (left parietal area) is more significant; but the difference of the area under the amplitude did not reach statistical significance. In the IVA-CPT tests, the combined attention quotient, combined control quotient, auditory control quotient, visual control quotient, auditory and visual attention quotient in children with ADHD decreased significantly (P<0.05). In addition, the amplitude of IVA-CPT was positively correlated with visual attention and visual control quotient in F3 (left frontal region), Cz (central region) and P3 (left parietal area) (P<0.05); and the latency was negatively correlated with visual attention and visual control quotient in F3 (left frontal region), Cz (central region), P3 (left parietal area) (P<0.05).Conclusion:It was found that ADHD patients’ cognitive event-related potentials (N400) are significantly changed in the performance of reduced amplitude and prolonged latency. That’s may due to the dysfunction of visual attention and visual control functions. Tips that ADHD affects cognitive development of children.