Cortical auditory processing in preterm newborns: an ERP study.

The aim of this study was to investigate the effects of gestational age on the auditory event-related potentials (AERPs) in preterm newborns of extremely low (23-29 weeks, N=20) and low gestational age (30-34 weeks, N=19). All subjects were tested at the same post-conceptional age of 35 weeks. An auditory oddball paradigm was used with frequently occurring "standard" tones at 1000 Hz and rarely occurring "deviant" tones at 2000 Hz. Newborns of less than 30 gestational weeks showed smaller AERPs responses (P1i, N2i and mismatch response) than the older ones. Our results suggest the role of gestational age as the main factor explaining cortical functioning at this early age.