Due to computer errors, data from three participants in the control group were excluded from the analyses. RTs were limited to responses made between 100 ms and 1500 ms after target onset, to reduce the influence of a few outlying data points (< 1% of trials) and to eliminate fast “guessing” responses. Due to the relatively small number of trials contributing to post-error responses, within-group variance for these trials remained high. To reduce this within-group variability, the mean and standard deviation for post-error trials was calculated and a 1.5 SD cut-off was used to define outliers. A Winsorization scheme was used to modify the outlying data points by changing their values to the next most-extreme, non-outlying value in the distribution, maintaining their ordinal position while reducing their influence on the mean (see Tabachnick & Fidell, 2013; Wilcox, 2012). Nine data points were changed across the three groups. Accuracy data (proportion correct) were transformed using arcsine of the square root, which normalizes variance across conditions to produce distributions more suitable for analysis of variance (ANOVA). However, for ease of interpretation, raw
