Stroop Task

In this task, the measures of the median RTs obtained by participants in congruen<sup>t</sup> and incongruent trials were compared to calculate Stroop effects. These data were analyzed using analysis of variance with two factors manipulated between subjects, group (placebo, probiotic) and condition (congruent, incongruent), and one factor manipulated within subjects, treatment (pre-, post-). The results only showed a significant effect of condition (*p* < 0.01); no other significant effects were observed (*p* > 0.05). The negative priming effect was also calculated by comparing the measures of the median RTs obtained by participants in control trials vs. incongruent trials. No effect or interaction was statistically significant (*p* > 0.05) (Table 6).


**Table 6.** The average median of RTs and errors expressed by mean and standard error.
