Sequence imitation and reaching measures of executive control: a longitudinal examination in the second year of life.

Despite increasing interest in the early development of executive control, few assessment tools are available for use in the second year of life. At 15 and 20 months, children completed a task battery that included reaching and sequence imitation tasks expected to require executive control. With age, children showed reduced perseveration and increased ability to resist interference across trials and from distractors. At each age, A-not-B with invisible displacement was correlated with one of the sequence imitation tasks modified to increase executive control demands. Correlations between child performance on individual tasks at 15 and 20 months were generally low.