Maturation of the auditory event-related potentials during the first year of life

Abstract

This study examined the maturation of cortical auditory event-related potentials (ERPs) from birth until 12 months of age. In the 15 infants studied, all ERP peaks observable at 12 months of age, the P150, N250, P350, and N450 were identifiable already at birth, As in previous studies, the amplitudes of the ERP peaks increased and latencies shortened with increasing age. In addition, the time courses of the amplitude growth of these peaks differed from each other. It was concluded, that the generators of all the infantile ERP peaks are functional already at birth, and that the maturational changes in the waveform morphology can mostly be accounted for by the changing relative strengths of the different generators.

Event-related potentials reflect spectral differences in speech and non-speech stimuli in children and adults

“…However, an explanation exists. First, data shows that the N4 emerges as early as by 3 months of age (Kushnerenko et al, 2002). If the N4 indeed reflects larger-scale sound organization, its early emergence would be consistent with the evidence showing that infants are capable of processing larger-scale stimulus attributes, such as prosody, words en bloc, and distinct streams of auditory information (Werker and Polka, 1993;Best, 1994;Winkler et al, 2003).…”

“…In rudimentary form, this complex is present at birth and is fully formed by 6-9 months of age (Kurtzberg et al, 1986;Kushnerenko et al, 2002). This age is remarkable for rapid acquisition of receptive language.…”

“…Some researchers posit that auditory P2 emerges early in infancy (Barnet et al, 1975;Kurtzberg et al, 1984;Novak et al, 1989), while others state that it does not appear until 5-6 years of age (Ponton et al, 2000). This is difficult to resolve since only one positivity, traditionally identified as the P1, is present in infants and young children (Ponton et al, 2000;Kushnerenko et al, 2002;Èeponienë et al, 2002). However, a recent study that used very long inter-stimulus intervals (3-6 sec) was able to demonstrate both the N1 and P2 peaks in infants (Wunderlich et al, 2006).…”

Newborn infants can organize the auditory world

“…The actual brain responses of newborns and adults, of course, are quite different (for reviews of the maturation of electric brain responses, see refs. [19][20][21] and, because newborns were asleep during the experiment, only a positive electric brain-response difference was elicited in them (14), whereas adults showed both a negative (MMN) and a positive (P3a) response difference.…”

Familiar words capture the attention of 11-month-olds in less than 250 ms

“…P150, N250, P350, and N450 [11]. Although the functional significance of these peaks and their relation to ERP peaks observed in adults remain a subject for speculation, the modulation of the infant N2 to auditory input variations is a well established effect thought to be automatic and involuntary, from 0 to 12 months and into adulthood [12].…”