Yu Sun Chung ^1,2* Berry Van Den Berg ³ Kenneth C Roberts ² Armen Bagdasarov ² Marty G Woldorff ² Michael S Gaffrey ^2,4

• ¹ Kean University, Union, United States
• ² Duke University, Durham, North Carolina, United States
• ³ University of Groningen, Groningen, Netherlands
• ⁴ Medical College of Wisconsin, Milwaukee, Wisconsin, United States

Both adults and children learn through feedback to associate environmental events and choices with reward, a process known as reinforcement learning (RL). However, tasks to assess RL-related neurocognitive processes in children have been limited. This study validated a Child version of the Probabilistic Reward Learning task in preadolescents (8-12 years) while recording event-related-potential (ERPs), focusing on: (1) reward-feedback sensitivity (frontal Reward-related Positivity, RewP), (2) late attention-related responses to feedback (parietal P300), and (3) attentional shifting toward favored stimuli (N2pc). Behaviorally, as expected, preadolescents could learn stimulus-reward outcome associations, but with varying performance levels. Poor learners showed greater RewP amplitudes compared to good learners. Learning strategies (i.e., Win-Lose-Stay-Shift) were reflected by the feedback-elicited P300 amplitudes. Lastly, attention shifted toward to-be-chosen stimuli, as evidenced by the N2pc, but not toward more highly rewarded stimuli as in adults. These findings provide novel insights into the neural processes underlying RL in preadolescents.