Rewards Can Foster Response Execution and Response Inhibition in Young Children Diagnosed with ADHD

ABSTRACT Children with ADHD show deficits in executive functioning, especially the ability to inhibit inadequate responses, and deficits in motivational processes due to dopaminergic dysfunctions. There is evidence that rewards can foster inhibition in children with ADHD. However, most studies examined a wide age range of children above 7 years of age, so almost nothing is known about inhibition and reward effects on inhibition in younger children. The primary goals of the present study were a) to examine response inhibition in young children with ADHD in a relatively narrow age range (5–8 years) in comparison to children without ADHD b) to investigate whether performance in an inhibition task can be fostered by rewards in this young age group. For this purpose, children with ADHD (n = 20) and control children (n = 20) were recruited from schools as well as pediatric, psychiatric, and psychological practices in North Rhine-Westphalia, Germany. Children conducted a Go/NoGo task under a non-rewarded and a rewarded condition. Our findings demonstrate a generally decreased response inhibition in ADHD as compared to control children. Rewards led to improvements in response inhibition in both groups of children. However, in contrast to control children whose ability to inhibit increased with practice in both conditions, children with ADHD inhibition decreased over the course of the non-rewarded condition but was raised by the prospect of a reward at the start of the reward condition. Thus, it seems that already at this young age, German children without ADHD are better able to keep their inhibition ability up over time than children with ADHD.