Boosting executive functions and math abilities in adolescents with dyscalculia: the combined effect of prismatic adaptation and cognitive training

Developmental dyscalculia (DD) is a neurodevelopmental disorder characterized by both functional and structural brain modifications. Individuals with DD exhibit impairments in higher-order cognitive processes. Timely intervention is crucial, as difficulties in mathematical learning can impact academic achievement, contribute to behavioral problems, and increase the risk of school dropout. This study aims to explore whether targeting higher-order cognitive processes could partially remediate developmental dyscalculia, with pre-registered primary outcomes including numerical facts, mental calculation speed, and mental calculation accuracy (ISRCTN, ISRCTN15190285). We conducted a single-center, two-arm, randomized controlled trial. Seventy adolescents aged 13–17 years, who had recently received a first diagnosis of developmental dyscalculia, were randomly assigned to either the intervention or waitlist group. The intervention leveraged the synergy between an initial stimulation phase—utilizing prismatic adaptation, a bottom-up visuomotor rehabilitation technique, to activate neural activity in brain regions involved in cognitive processing—followed by a targeted (top-down) cognitive training phase designed to strengthen the specific skills underlying mathematical deficits. Group differences over time were examined using a general linear model with two groups (treatment vs. control) and two-time points (pre- and post-treatment) for each outcome variable. Significant increases were observed in the working memory index (between group change = 16.51 (CI = 13.59–19.44); p < 0.001, η2 = 0.66), processing speed index (between group change = 12.40 (CI = 9.73–15.70); p < 0.001, η2 = 0.58), mental calculation speed (between group change = 0.74 (CI = 0.55–0.93); p < 0.001, η2 = 0.46), mental calculation accuracy (between group change = 0.43 (CI = 0.14–0.71); p < 0.001, η2 = 0.17), and numerical fact retrieval (between group change = 14.07 (CI = 8.58–19.56); p < 0.001, η2 = 0.31). These findings suggest that combining neurostimulation via prismatic adaptation with targeted cognitive training using serious games enhances both mathematical accuracy and response speed, as well as executive functions, attention, inhibition, and cognitive processing. Prismatic adaptation appears to enhance activity in brain regions that are subsequently reinforced by cognitive training. This innovative approach could have important implications for the early remediation of core neuropsychological deficits in dyscalculia.