DEVELOPMENTAL-CHANGES IN P1 AND N1 CENTRAL AUDITORY RESPONSES ELICITED BY CONSONANT-VOWEL SYLLABLES

Normal maturation and functioning of the central auditory system affec ts the development of speech perception and oral language capabilities . This study examined maturation of central auditory pathways as refle cted by age-related changes in the P1/N1 components of the auditory ev oked potential (AEP). A synthesized consonant-vowel syllable (ba) was used to elicit cortical AEPs in 86 normal children ranging in age from 6 to 15 years and ten normal adults, Distinct age-related changes wer e observed in the morphology of the AEP waveform. The adult response c onsists of a prominent negativity (N1) at about 100 ms, preceded by a smaller P1 component at about 50 ms. In contrast, the child response i s characterized by a large P1 response at about 100 ms. This wave decr eases significantly in latency and amplitude up to about 20 gears of a ge. In children, P1 is followed by a broad negativity at about 200 ms which we term N1b. Many subjects (especially older children) also show an earlier negativity (N1a). Both N1a and N1b latencies decrease sign ificantly with age. Amplitudes of N1a and N1b do not show significant ape-related changes. All children have the N1b; however, the frequency of occurrence of N1a increases with age. Data indicate that the child P1 develops systematically into the adult response; however, the rela tionship of N1a and N1b to the adult N1 is unclear. These results indi cate that maturational changes in the central auditory system are comp lex and extend well into the second decade of life. (C) 1997 Elsevier Science Ireland Ltd.