Executive functions (EF) are a set of effortful cognitive processes that allow children to control their thoughts, emotions, behaviors, update information in their memory and be mentally flexible. The literature shows that the development of EF is essential for school success, in addition to being an important predictor of quality of life in adulthood. As a result, numerous interventions have sought to stimulate EF development through different programs and formats, typically reporting moderate effectiveness in improving core EF components. However, evidence for effects on untrained, domain-specific areas, such as academic performance, is less consistent. One explanation for these mixed findings may lie in the heterogeneity of interventions and participant characteristics; particularly regarding the modality of the intervention (e.g., using digital media versus traditional media) and children's stage of development. Although the current literature suggests these factors moderate intervention efficacy, there is a lack of randomized controlled trials that compare these variables within a single design. To address this gap, a randomized controlled study has been proposed, aimed at examining an EF intervention delivered in one of three modalities-traditional (paper-and-pencil), digital (computer-based), and mixed-in low-income, urban Chilean school children at two developmental stages (5-6 years and 9-10 years). Each program will target core EF components and measure both efficacy in EF improvement and outcomes in literacy and math skills. By contrasting these intervention modalities across distinct age groups, this study seeks to identify whether developmental level and format have moderating effects on EF improvement and academic performance. Our findings will contribute to ongoing debates about the best practices for EF stimulation, potentially informing evidence-based interventions that can be scaled or adapted for children at different developmental stages and in under-resourced settings. In doing so, this research seeks to clarify how, when, and for whom EF interventions yield lasting benefits beyond immediate cognitive skills.

Inclusion Criteria:

• Schools must be classified by the Chilean government as being public elementary schools located in an urban setting, with a proportion of vulnerability of at least 70% or greater (index for socioeconomic status). Schools also must contain at least one kindergarten class.
• For participants, the children must be regularly attending either kindergarten, or the fourth or fifth grade.

Exclusion Criteria:

• Schools that are considered rural, private or subsidized are not eligible. Additionally, schools that have a vulnerability index of less than 70% are not eligible.
• For participants, children with an intellectual disability, or are unable to understand and speak Spanish, will be excluded from the data analysis.

The study will follow open science guidelines in that the anonymized data and the R analysis script will be made available on the OSF registry of this study. Parents and guardians will be informed of this process in the informed consent form.

The protocol, SAP and ICF are currently available on the OSF study registry (start date: March 11, 2025). Analytic code will be when the statistical analyses are complete (estimated date: June, 2026). This data will be available for five years, as per guidelines set by the University of Talca's Scientific Ethics Commitee.

Anyone with the provided link will be able to access this information.