Auditory ERP in extremely premature 5-year-old children

The aim of this research was to test the hypothesis of a functional impairment in the automatic detection of deviant tones in 141 children born after 25 to 28 weeks of gestational age, as compared to 45 age-matched full-term control children. All of them were assessed at age 5 years 9 months and instructed to listen passively to two different pure tones (1000 vs 1200 Hz; 20 vs 80%) counterbalanced between ears. Rarity was thus defined by specific ear by tone combinations. The temporal N100 showed a clear contralateral functional organization of the central auditory pathway, especially for the left ear, but without group difference. By contrast, in full-term controls but not in premature children, the central N200 was specifically increased over frontal leads to rare stimuli as compared to frequent. Premature children demonstrated a lack of brain response when more complex processing integrating different informations was required.