• cognitive development;
  • interference control;
  • executive function;
  • Stroop effect


Two experiments investigated preschoolers' interference control in variants of the day–night task. The day–night task involves instructing children across 16 trials to say the word ‘day’ when viewing a card depicting a nighttime sky and to say ‘night’ when shown a picture of the daytime sky. The purpose of the experiments was to investigate whether the depiction on each card distracts children because it is semantically associated with the instructed response or because the depicted item cues the alternative (incorrect) response within the response set. The results in the first study (N=23, M=52.65 months) and second study (N=54, M=50.81 months) indicate that a close semantic relation between the picture and the target response does not pose substantial interference for preschoolers. In contrast, the pictured item poses a significant challenge for preschoolers when it depicts the interfering alternative in the response set. Theoretical implications of these results for the development of interference control are discussed. Copyright © 2008 John Wiley & Sons, Ltd.