[The effect of age in a planning and arranging task ('Mexican pyramid') among schoolchildren]

To analyze the influence of age on the performance of a planning and organization task, two skills included in the executive functions.

Performance of the task 'Mexican pyramid' from the Evaluacion Neuropsicologica Infantil (ENI) were analyzed on 239 school age children from México and Colombia, distributed in six age groups. Five measures were analyzed: number of correct designs, number of movements per design and execution time in the correct designs, number of correct designs built with the minimum of movements and its execution time.

There was a significant effect of age on the five measures. Comparison between groups showed that younger children (5 to 6 years old) had a smaller number of correct designs, while children from 5 to 8 years old need more movements. Execution time showed a greater number of differences between groups. Analyzing the 11 items of the task, it was evident that difficulty level is related with the number of movements and the novelty of rules.

Our results suggest that accuracy of performance, the number of moves as well as the speed of performance are useful markers of the development of the executive functions. Our results support the notion that the development of planning and organization; is fast in the first years of the school age, and it slows down on adolescence.