Evidence for Both Task and Information Conflicts in the Color-Digit Stroop Task

The color-digit Stroop task was used to examine information and task conflicts through response times (RTs) and pupil dilation. RTs showed typical interference and facilitation (slower incongruent, faster congruent), suggesting information conflict. Pupil data showed greater dilation for incongruent versus congruent trials later in the trial, indicating information conflict. Both congruent and incongruent trials also showed greater dilation than neutral trials, reflecting task conflict not visible in RTs. Task conflict appeared early, suggesting automatic processing of numerical meaning, whereas information conflict emerged later. This dissociation demonstrates that physiological measures capture hidden cognitive challenges. The color-digit Stroop task, being simple and language- (and culture-) independent, may serve as a promising tool for studying mathematical learning difficulties and guiding interventions.