Alterations in reward processing are frequently reported in ADHD. One important factor that affects reward processing is the quality of reward, as social and monetary, rewards are processed by different neural networks. However, effect of reward type on reward processing in ADHD was not extensively studied.

We aimed to explore the effect of reward type (i.e., social or monetary) on different phases of reward processing and also to test the hypothesis that ADHD symptoms may be associated with a problem in processing of social rewards.

We recorded event-related potentials (ERPs) during a spatial attention paradigm in which cues heralded availability and type of the upcoming reward and feedbacks informed about the reward earned. Thirty-nine (19 males and 20 females) healthy individuals (age range: 19–27) participated in the study. ADHD symptoms were measured using ADHD self-report scale (ASRS).

The feedback related potentials, namely feedback related negativity (FRN), P200 and P300 amplitudes, were larger for social rewards compared to monetary rewards (Fig. 1). There was a consistent negative correlation between the hyperactivity subscale of ASRS and almost all feedback related ERPs. ERP amplitudes after social rewards were smaller for individuals with more hyperactivity.

Our findings suggest that hypo responsiveness to social rewards may be associated with hyperactivity. However, the results have to be confirmed with clinical populations.