Electric brain responses obtained from newborn infants to changes in duration in complex harmonic tones

Event-related brain potentials of 10 full-term newborns in response to duration changes in complex, harmonic tones known to elicit prominent mismatch negativity (MMN) response in adults were investigated. Here we report that duration changes elicited prominent MMN responses in all newborns tested. In contrast, MMN has been reported in as little as 50% of the infants in some previous studies using other sound attributes. When the infant MMN latency was compared with that obtained from adults, and 4- as well as 8-year-old children, it was found that the MMN latency was a bit later in newborns than in older age groups. This result is consistent with previous findings. The MMN amplitude, however, was surprisingly large in infants compared to older children.