Development of an aspect of executive control: development of the abilities to remember what I said and to "do as I say, not as I do".

Luria's tapping test (tap once when E taps twice, tap twice when E taps once) was administered to 160 children (80 males, 80 females) between 3 1/2 to 7 years old. Older children were faster and more accurate than younger children, with most of the improvement occurring by the age of 6. All children tested demonstrated understanding of the instructions during the pretest, and most started out performing well, but younger subjects could not sustain this. Over the 16 trials, percentage of correct responses decreased, especially among younger subjects. Performance here was compared with performance on the day-night Stroop-like task. The most common error on both tasks was to comply with only one of the two rules. Other errors included tapping many times regardless of what the experimenter did and doing the same thing as the experimenter, rather than the opposite. It is suggested that the tapping task requires both the ability to hold two rules in mind and the ability to inhibit a strong response tendency, that these abilities improve between 3-6 years of age, and that this improvement may reflect important changes within frontal cortex during this period of life.