Differential P300 Signatures of Executive Dysfunction in Attention-Deficit/Hyperactivity Disorder and Borderline Intellectual Functioning

Background: Attention-deficit/hyperactivity disorder (ADHD) and borderline intellectual functioning (BIF) are developmental conditions frequently characterized by executive dysfunction. However, the cognitive and neurophysiological differences between these conditions remain insufficiently defined. This study aimed to examine the behavioral and electrophysiological features of executive function in children with ADHD and BIF. Methods: Children with ADHD and BIF, along with typically developing controls, completed computerized Stroop and Go/No-Go tasks while electroencephalography was recorded. Behavioral performance was evaluated using reaction times, accuracy indices, omission errors, and commission errors. Electrophysiological analyses focused on P300 event-related potential amplitude and latency at frontal (F3, F4) and central (C3) electrode sites. Results: Children with BIF demonstrated slower reaction times, increased omission errors, and prolonged P300 latency at the F4 electrode, indicating reduced processing speed and attentional inefficiency. In contrast, children with ADHD exhibited faster but more error-prone response patterns, characterized by increased commission errors and shorter P300 latency, consistent with impulsivity and impaired inhibitory control. Conclusion: Attention-deficit/hyperactivity disorder and BIF share executive dysfunction but differ in underlying cognitive and neurophysiological profiles. Attention-deficit/hyperactivity disorder is primarily associated with disinhibition, whereas BIF is characterized by reduced processing speed and impaired sustained attention. Differences in P300 patterns may help distinguish between these conditions and support diagnosis and individualized intervention strategies.