Further manipulation of the stop-signal task: developmental changes in the ability to inhibit responding with longer stop-signal delays.

The stop-signal task, a measure of inhibitory control, was further modified in order to examine its suitability as a task for very young children. A previous study (Carver et al., 2001) showed that it can be successfully adapted for use with primary school-aged children. The present study manipulated the presentation of the signal to inhibit responding and found that this improved the likelihood of responding. A pre-primary school group of children (< 5 years, 6 months), a young primary school group (5 years, 7 months to 7 years, 6 months), and a mid-primary school group (7 years, 7 months to 9 years, 6 months) participated in the study. The results emphasize the pre- and early school years as a sensitive time for the development of inhibitory skills. Measures of inhibitory control must therefore be age-appropriate and sensitive to these early developmental changes.