Computer-Based Training in Math and Working Memory Improves Cognitive Skills and Academic Achievement in Primary School Children: Behavioral Results

Student academic achievement has been positively related to further development outcomes, such as the attainment of higher educational, employment, and socioeconomic aspirations. Among all the academic competences, mathematics has been identified as an essential skill in the field of international leadership as well as for those seeking positions in disciplines related to science, technology, and engineering. Given its positive consequences, studies have designed trainings to enhance children's mathematical skills. Additionally, the ability to regulate and control actions and cognitions, i.e., executive functions (EF), has been associated with school success, which has resulted in a strong effort to develop EF training programs to improve students' EF and academic achievement. The present study examined the efficacy of a school computer-based training composed of two components, namely, working memory and mathematics tasks. Among the advantages of using a computer-based training program is the ease with which it can be implemented in school settings and the ease by which the difficulty of the tasks can be adapted to fit the child's ability level. To test the effects of the training, children's cognitive skills (EF and IQ) and their school achievement (math and language grades and abilities) were evaluated. The results revealed a significant improvement in cognitive skills, such as non-verbal IQ and inhibition, and better school performance in math and reading among the children who participated in the training compared to those children who did not. Most of the improvements were related to training on WM tasks. These findings confirmed the efficacy of a computer-based training that combined WM and mathematics activities as part of the school routines based on the training's impact on children's academic competences and cognitive skills.

child had to press the right button for two stimuli and the left button for the other two stimuli; 6 stimuli, where the child had to press the right button for three stimuli and the left button for the other three stimuli. There was also a level with 8 stimuli, where the child had to press the right button for four stimuli and the left button for the other four stimuli, but no one reached this level.
Within each set size, there were 5 levels of difficulty that were determined by the maximum time the child had to respond. In the easiest level, the child had 10 seconds to respond. We considered the child's average reaction times on that first block and estimated the maximum response times for the other levels using the following mathematical formulae: Average + SD/2 (2nd difficulty level); Average (3rd difficulty level); Average -SD/2 (4th difficulty level); Average -SD (5th difficulty level).
The experimental design for this task is presented in Supplementary Figure 2. As in the n-back task, instructions were presented on the screen until the child was ready, i.e., s/he had to press a bottom to continue, and a white screen with the word loading appeared for 3 seconds. Each trial started with a white screen (500 or 1000 ms, randomly assigned), and the stimulus was then presented. The child was required to respond within a specific time period that was dependent of the level of difficulty. On the same screen, the child received an audio feedback, which lasted 500 ms, for each response-one sound for correct responses and another sound for incorrect responses. Each block was composed of 24 trials. A 95% correct rate on a block was considered a successful performance for that block, and when the child successfully completed two blocks, s/he was advanced to the next level.

Working memory span task
We manipulated 2 variables, i.e., set size and retention time, to create different levels of difficulty. With respect to set size, from the easiest level to the most difficult level, we had 3, 4, 5, and 6 stimuli presented, including the target. The retention time, from when the set presentation finished and a question mark appeared (see Supplementary Figure 3 for the experimental design) to when the child must respond, also had four levels of difficulty: 1000, 2000, 4000, and 8000 ms.
As in the other tasks, instructions were presented on the screen until the child was ready (s/he had to press a bottom to continue), and a white screen with the word "loading" appeared for 3 seconds. Each trial began with a white screen (500 or 1000 ms, randomly assigned) that preceded the presentation of the stimuli (500 ms), between which a white screen appeared (500 ms). The stimuli presentation, the time of which was dependent on the level of difficulty, ended with a question mark, followed by a screen in which two stimuli appeared to which the child was required to reply (2000 ms). Once the child responded, an audio feedback was presented (500 ms, one sound for correct and another for incorrect). Each block was composed of 20 trials. When the child achieved 95% accuracy in a block, it was considered a successful performance, and when the child successfully completed two blocks, s/he passed to a higher level of difficulty.

Supplementary Tables
Supplementary Table 1. Math training tasks and descriptions used in this study.

Rain of numbers
In this activity the child was required to solve correctly the highest number of mathematical operations, within a time limit of two minutes. The mathematical operations presented were additions, subtractions, divisions, and multiplications.

Numerical series
This task consisted in to complete the highest number of numerical sequences, within a time limit of two minutes.

Day-to-day situations
This activity asked the child to solve the highest number of mathematical problems, within a time limit of two minutes.

Magic numbers
In this task the child was required to identify the highest number of digits within a matrix in a time limit of two minutes.

Digits discrimination
In this activity the child had to able to sort the highest number of digits list, in ascending order, and in decreasing order. At the same time, some digits were presented upside-down and the child had to identify the highest number of them as soon as possible.

To complete operations
The task presented to the child some mathematical operations without some numbers or without numeric symbols, and s/he was asked to complete the highest number of mathematical operations within a time limit of two minutes.