EVENT-RELATED POTENTIAL STUDIES IN INFANTS AND CHILDREN

The current status of event-related potentials (ERPs) in infants and children is discussed based on a review of the relevant literature. Although the N 100-P200 component evoked by tone stimuli is clearly detected using an odd-ball paradigm in children over approximately 6 years of age, that component evoked by speech stimuli is not clearly detected until at least 10 years of age. In contrast to the adult N100-P200 component evoked by speech stimuli, infants and young children show a positivity at a latency of about 85-120 ms and a negagativity at about 200-240 ms. The definition of P300 in children has not yet been established. P300 latency evoked by both auditory and visual stimuli decreases throughout childhood and reaches the mature value by puberty or young adulthood. However, P300s elicited by auditory and visual stimuli show different developmental time courses from each other, suggesting that they may originate from different neural generators. The Nc component is elicited by a variety of attention-getting events in infants and children. Interestingly, the developmental change in the Nc amplitude parallels the maturational course of synaptogenesis in the frontal cortex, and the Nc latency reaches the mature value at the time when myelinogenesis is complete in the nonspecific thalamic radiation.