DUAL CEREBRAL PROCESSING OF ELEMENTARY AUDITORY INPUT IN CHILDREN

We compared event-related responses (ERPs) to non-attended frequent an d intermittent auditory input in school-aged children and in young adu lts. In adults, both inputs elicited prominent auditory N100 responses at vertex. In children, intermittent stimulation evoked vertex respon ses with similar latency and refractoriness, whereas frequently delive red identical tones evoked responses on average at 240 ms. Sensitizati on of a separate neuronal population at 260-300 ms was obvious during intermittent stimulation in children. The dual behaviour, simultaneous 'habituation' of one neuronal population response and sensitization o f another, may reflect the process of redirecting the attention and se tting up a neuronal model. Furthermore, results suggest that a simplis tic interpretation of developmental ERPs in which shortening of latenc ies represents maturation is insufficient.