Error monitoring and ADHD symptoms in adults: The effect of laterality and state regulation

Evidence is accumulating that error monitoring is impaired in individuals with ADHD. The study aims to investigate the contribution of brain laterality and effort allocation/state regulation to impaired error monitoring in adults with ADHD symptoms. Based on the scores on the Conners’ Adult ADHD Rating Scales, a group with high and one with low ADHD were formed. The groups performed a lateralized lexical decision task with short and long ISI tapping effort allocation. Error monitoring is measured by post-error adjustments. Results showed that after errors subjects with low ADHD slowed down and improved their response accuracy only for the right visual field stimuli during long ISI. These adjustments were absent in subjects with high ADHD. Results suggest that impaired error monitoring in ADHD is related with affected left hemisphere when extra effort allocation is needed.