highly significantp < .001
The difference between error and correct responses was highly significant ( p < .001) for both ERP components at each of the three time points. 3.2 Effects of demographic covariates on ERN The linear mixed-effect model showed no significant effect of gender on the ERN amplitude ( p > .1), however, the effect of ethnicity was significant ( F (1,408.1) = 9.07, p < .01), indicating larger ERN amplitude in Caucasians relative to minorities.