Monetary Rewards Modulate Working Memory Performance During Adolescence

Rewards can be powerful motivators for higher-order cognition, and adults typically improve performance on demanding tasks when high incentives are at stake. However, less is known about how rewards influence executive function during adolescence, and few studies have examined the developmental emergence of when rewards modulate adolescents’ working memory (WM) performance. Because WM continues to mature from childhood to adulthood and differentiates from other executive processes in early adolescence, we examined how rewards modulate adolescents’ WM performance and whether this modulation changes with age. Participants aged 10-20 (Nusable=187) completed a neutral N-back working memory task (no payout) and a rewarded N-back task with low-magnitude and high-magnitude rewards. To assess subjective perceptions of cognitive effort and reward value, participants also completed a cognitive effort discounting task and provided subjective ratings of task demands and monetary payouts. During the rewarded N-back task, participants of all ages exhibited increased accuracy for high- relative to low-magnitude rewards. However, when comparing performance in rewarded versus neutral N-back tasks, younger adolescents’ WM benefited the most from reward, and this benefit decreased with age. Effort discounting and subjective ratings were age-invariant, indicating that age-related differences in reward-modulated WM were not explained by subjective differences in perceived effort demands or reward values. These findings reveal that rewards enhance WM throughout adolescence, particularly at younger ages. This work also reveals that reward-related improvements in cognitive function emerge earlier in development for working memory than other executive function domains.