Age differences in neural response to reward and loss in children

The goal of this study was to examine age-related differences in children's reward processing. Focusing on reward outcome processing, we used event-related potentials to examine substages of neural response to gain versus loss feedback in a sample of 7-11-year-old children (M = 9.67, SD = 1.40) recruited from the community (N = 234; 47.6% girls, 66.2% non-Hispanic European American). Using principal components analysis (PCA), we focused on temporospatial combinations that closely resembled the RewP, fb-P3, and fb-LPP in temporal and spatial distributions. Two of these, the PCA factors reflecting the RewP and fb-LPP, demonstrated age-related differences in response to gains versus losses. Age-related changes in the RewP were specific to gain feedback, with RewP amplitudes to gain, but not loss, increasing from middle to late childhood. In contrast, age-related changes in fb-LPP were specific to loss feedback, with fb-LPP amplitudes to losses, but not gains, decreasing from middle to late childhood. Follow-up analyses revealed that children younger than age 8 exhibited larger fb-LPP responses to loss than gain, whereas children older than age 10 exhibited larger RewP responses to gain than loss. Similar results were obtained using mean amplitude-based ERP indices and the results do not appear to have been due to age-related differences in the latency or location of the ERPs themselves. These results highlight the importance of examining distinct substages of reward outcome processing and suggest that robust neural responses to loss feedback may emerge earlier in childhood than responses to gains.