Development and topography of auditory event-related potentials, mismatch and processing negativity from 8 to 22 years of age.
Introduction: How do ERPs reflecting auditory information processing develop across adolescence? This development is described for the amplitude and latency of five ERP components and four difference-waves in four groups of 11 healthy subjects with mean ages of 10, 14, 17 & 21 years. Methods: Vector normalised data were recorded from 19 sites during diffuse and focused attention in a three-tone oddball. (i.e. in passive, diffuse-attention and active, focussed-attention, discrimination conditions) to see how ERP loci varied with age for tone-type, attention-condition and for four types of difference-wave reflecting nontarget and target comparisons: (mismatch negativity, MMN, an auditory working memory trace; Negative difference, Nd, an attentional trace, but also Processing Negativity, PN and the Goodin-waveform). Results: Age interacted with site for most components. P1 loci sensitive to rare tones moved posteriorly and N1 loci lost their right bias at early puberty (figure 1). But P2 loci did not move anterior to Cz until adulthood. N2 amplitude, sensitive to attention condition, developed a mature frontal focus by 17 years. Right-biased P3 loci move to the midline with focused attention in young and old alike (figure 1). Difference-waves reflected three developmental stages (figure 2): In 10 year-olds early deflections (<150 ms) were diffusely distributed; in mid-adolescence the main frontal negative component (150-300 ms) became well-formed and lost an earlier right bias; over 17 years the late positive complex developed a right bias in target-derived waves. Latency decreases for early frontal components were marked in 10-14y olds and for later posterior components in 14-17y olds. MMN topography matured (from a right lateral to bilateral distribution) between 10 and 14 y, while Nd topography matured and became bilateral between 14 and 17y (figure 5). Conclusions: Major developments of brain function appear at the onset of adolescence (<14y) in early stimulus-selection processes and during adolescence in the differential use of this information