Fluid intelligence and neural mechanisms of conflict adaptation

• High IQ group had shorter RTs in the cI, iC, and iI trials than average IQ group.
• High IQ group had better adaptation performance (lower RT-CAE) than average group.
• High IQ group showed smaller SP-CAE for better adaptation control processing.
• High IQ group had larger SP amplitudes than average IQ group in the iI condition.

The current study investigated whether adolescents with different intellectual levels have different conflict adaptation processes. Adolescents with high and average IQ abilities were enrolled, and their behavioral responses and event-related potentials (ERPs) were recorded during a modified Eriksen flanker task. Both groups showed reliable conflict adaptation effects (CAE) with regard to the reaction time (RT), and they showed a faster response to the cC condition than to the iC condition and faster response to the iI condition than to the cI condition. The IQ-related findings showed that high IQ adolescents had shorter RTs than their average-IQ counterparts in the cI, iC, and iI conditions, with smaller RT-CAE values. These findings indicated that high IQ adolescents had superior conflict adaptation processes. The electrophysiological findings showed that the cI condition required more conflict monitoring processes than the cC condition through the induction of more negative N450 responses. With regard to the adaptation control processes, high IQ adolescents showed greater slow potential (SP) amplitudes than their average IQ peers in the iI condition; furthermore, they showed better adaptation control processing with smaller SP amplitude-CAE values. In conclusion, the present study revealed the essential association between fluid intelligence and conflict adaptation processes.