Using Item Response Theory to address challenges with measuring executive function in infancy and early childhood

The current study aimed to evaluate the psychometric properties of eight executive function (EF) tasks designed for use in infancy and early childhood. Modern measurement theory and item response theory (IRT) frameworks were applied to examine the underlying latent ability influencing children’s performance on EF tasks. Longitudinal assessments at 8 months, 2.5 years, and 5 years were conducted as part of the FinnBrain Birth Cohort Study, and 830 participants from the larger cohort were included in the present study. The results indicated that the tasks included in the study were effective in measuring children’s EF abilities with a certain level of discrimination power. The difficulty level of each task varied across time points. In 8-month-old children, the A-not-B task scores were the most informative for assessing above-average levels of EF ability. At 2.5 years of age, the two EF tasks (Spin the Pots and Snack Delay) provided the most informative assessments for children with low to moderate levels of EF ability. Among 5-year-old children, three EF tasks measured ability levels only below the sample mean, whereas two additional tasks captured a broader range of EF abilities. The discussion highlights the benefits of applying IRT analysis to EF measurements and emphasises the need for reliable and scalable tools to assess how executive function changes among individuals during early childhood.