Sex differences in the neural processing of reward feedback in young children

Understanding whether sex-related differences in the associations between emotion negativity and reward processing are present in early childhood has the potential to critically inform the etiology and prevention of psychiatric disorders characterized by dysregulated negative affect. Previous research suggests that altered neural processing of reward is associated with elevated levels of negative affect in adolescents and that the patterns of these associations may show sex-related differences. However, few studies have investigated the relationship between negative affect and reward processing in young children and none have directly examined potential sex-related differences in this relationship during early childhood. The current study investigated potential sex-related differences in neural response to reward feedback using EEG and their sex-specific association with emotional negativity in 140 children 4-7 years of age. Children completed a developmentally appropriate reward processing task while EEG data was recorded. Temporospatial Principal Component Analysis was used to separate overlapping feedback-related ERP components, revealing that males had greater loss-related feedback negativity and gain- and loss-related P200 values than females. At the individual level, males also showed a negative correlation between emotional negativity scores and gain-related P200 amplitudes. In line with prior work in adults for sex differences in attentional biases to emotional stimuli, these results suggest that neural mechanisms leading to sex differences in abnormal development of emotional negativity may emerge during early childhood and grow in magnitude during adolescence.