Refining the understanding of inhibitory processes: how response prepotency is created and overcome


Adele Diamond, Department of Psychiatry, UBC, 2255 Wesbrook Mall, Vancouver, BC Canada V6T 2A1; e-mail:


Understanding (a) how responses become prepotent provides insights into when inhibition is needed in everyday life. Understanding (b) how response prepotency is overcome provides insights for helping children develop strategies for overcoming such tendencies. Concerning (a), on tasks such as the day-night Stroop-like task, is the difficulty with inhibiting saying the name of the stimulus due to the name being semantically related to the correct response or to its being a valid response on the task (i.e. a member of the response set) though incorrect for this stimulus? Experiment 1 (with 40 4-year-olds) suggests that prepotency is caused by membership in the response set and not semantic relation. Concerning (b), Diamond, Kirkham and Amso (2002) found that 4-year-olds could succeed on the day-night task if the experimenter sang a ditty after showing the stimulus card, before the child was to respond. They concluded that it was because delaying children’s responses gave them time to compute the correct answer. However, Experiment 2 (with 90 3-year-olds) suggests that such a delay helps because it gives the incorrect, prepotent response time to passively dissipate, not because of active computation during the delay.