JMIR Publications

ABSTRACT

Background:

Digital health technologies increasingly employ tablet-based cognitive assessments for children, yet interaction design choices can substantially influence cognitive load and measurement validity. While cognitive load has been extensively studied in educational settings, its impact on patient-facing digital assessment tools for pediatric populations remains underexplored. Understanding how interface design affects both performance and clinical validity is essential for developing developmentally appropriate digital health applications.

Objective:

This study examined how interaction format influences cognitive load and measurement validity in a tablet-based Stroop task for children, comparing text-based response selection with color-based response selection to determine which format better supports valid attention assessment.

Methods:

A total of 127 typically developing children aged 6-12 years (mean 9.15 years, SD 1.56; 55 girls, 72 boys) completed both response formats in a within-participant design. Cognitive load was indexed using prefrontal Functional Near-Infrared Spectroscopy (fNIRS), measuring changes in functional connectivity and global network efficiency. Behavioral performance included accuracy, reaction time, and composite efficiency. Clinical validity was evaluated by correlating task performance with parent-reported attention problems. Random Forest analyses examined predictors of performance variance.

Results:

The color-based format yielded significantly better behavioral performance: higher accuracy (0.91 vs 0.86, P<.001, d=0.38), faster reaction times (1183 ms vs 1269 ms, P<.001, d=0.69), and superior composite performance (P<.001, d=0.72). Color-based performance showed a significant correlation with parent-reported attention problems (r=−.20, P=.025), whereas text-based performance did not (r=−.05, P=.56). While neural indices did not differ significantly between conditions, individual variations in prefrontal efficiency accounted for 35-44% of residual performance variance after controlling for age and general cognitive ability.

Conclusions:

Interaction format substantially influences both cognitive load and measurement validity in pediatric digital assessments. Color-based response formats that minimize extraneous semantic processing yielded superior performance and stronger clinical validity compared to text-based formats. For Stroop-based attention assessments in children, prioritizing response formats that reduce unnecessary cognitive demands may enhance measurement fidelity and clinical utility. Clinical Trial: N/A