Stronger impulse capture and impaired inhibition of prepotent action in children with ADHD performing a Simon task: An electromyographic study.

Abstract

A deficit in interference control is commonly reported in children with attention deficit hyperactivity disorder (ADHD). This has mainly been interpreted as a difficulty in inhibiting inappropriate responses. However, it could be due to at least two distinct and independent processes, which are often confounded: The activation or suppression of impulsive responses. The aim of the present study was to separate the contribution of these two processes. We compared performance of 26 children with ADHD to that of 26 nonADHD children using a novel approach based on electromyographic activity (EMG) analysis. EMG allows two distinct indices to be computed: Incorrect activation rate, which is an index of the intensity of impulse capture and correction rate, which provides a direct measure of the ability to suppress automatic responses. Children with ADHD were slower, committed more errors, and had a larger interference effect than nonADHD children. Moreover, we observed a greater incorrect activation rate and a lower correction rate in the ADHD group. Our data suggest that the difficulties in interference control found in children with ADHD are explained by both impaired inhibitory processes and a greater propensity to activate automatic responses. (PsycInfo Database Record (c) 2021 APA, all rights reserved).