Developmental changes in P300 wave elicited during two different experimental conditions.

Age-related correlations on auditory event-related potentials were studied using a task-relevant oddball paradigm in 175 normal subjects aged 4-21 years and age-related correlations in the "ignore" condition were studied in 108 normal subjects aged 1-21 years. In the ignore condition, subjects more than 4 years of age were instructed to read a book to divert attention from the auditory stimulus. From 4 to about 17 years of age, the latencies of task-relevant P300 in event-related potentials (ERPs) gradually shortened. In the ignore condition experiment, the P300 latency shortened progressively, but stabilized at about 12 years of age. Whereas P300 in the ignore condition likely corresponds to P3a described previously (passive attention), the conventional P300 wave corresponds to P3b (active attention). The findings indicate a developmental difference between the P3a and P3b potential.