Developmental changes in cognitive reaction time of children aged 6-12 years

Using a visual Go/Nogo paradigm and subtraction methods, we examined detailed developmental changes in the cognitive reaction times of 153 healthy children aged 6-12 years. Three conditions were studied: simple reaction, even rate reaction (50% Go), and high rate reaction (80% Go). The subtraction of simple reaction time from even rate reaction time was considered to reflect discrimination time, while the subtraction of simple reaction time from high rate reaction time was considered to reflect the time required for inhibition. We found that simple reaction time, even rate reaction time, and high rate reaction time all declined significantly with months of age (P 0.01). Furthermore, the times for both discrimination and inhibition also showed significant declines (P 0.01), which could be considered developmental changes in neural mechanisms involved in discrimination and inhibition processes. The time for inhibition showed a weaker correlation (P 0.01), which could indicate that the degree of developmental change is larger for the discriminative processes than for the inhibititory processes required for our task in the age range studied.