Prior studies that have relied on peak analysis have generally found decreasing peak amplitude and decreasing peak latency with maturation, although some conflicting results have been reported. Snyder and colleagues (1981) found that the amplitudes of the P50, N64, P100, and N150 peaks decreased with increasing age during adolescence.
12 In related work, Shearer and Dustman (1980) found that latencies of these peaks gradually increased over time.
13 Wright and colleagues (1985) found overall amplitudes were higher in their youngest age group (10–19 years) compared to the older age groups, and found no differences in peak latencies across age.
11 One limitation of this study was that prVEPs were averaged across subjects in 10-year age groups, which would have failed to capture differences of maturation during adolescence. Emmerson-Hanover and colleagues (1994), who examined a large cohort of 406 subjects ages 6 to 80 years, found somewhat different results. They observed that the P50 to N70 amplitude increased until about age 13 years and then decreased, whereas the N70 to P100 amplitude decreased with maturation.
10 They also found the P50, N70, and P100 peak latencies decreased during maturation.
10 Brecelj and colleagues (2002) also found in children 7 to 18 years old that P100 peak latency decreased with maturation.
18 Allison and colleagues (1983) similarly found the VEP P100 peak latency decreased between 4 and 19 years of age, although the peak latency of other peaks and peak amplitude were not reported.
9 We also observed that prVEP amplitude decreases with maturation using both the PCA model and peak analysis (see
Fig. 4 and
Supplementary Fig. S3b). Our PCA model also revealed a narrowing of the P100 peak with maturation that cannot be easily captured by standard peak analysis (see
Fig. 4b). Multiple PCs show a prominent change in the vicinity of the P100 peak. This reflects that there is substantial individual variation in the shape and the amplitude of the waveform in this temporal window. Age-related variability was predominantly described by PC2 and PC3. PrVEP changes with age in youth may be due to maturation of neural circuits within the visual pathway.
18 Head circumference did not appear to account for the differences we observed across age, although we cannot rule out the possibility that other physical characteristics, such as skull thickness
19 or age-related closing of cranial sutures,
20 could have played a role. Of note, our model of age-related effects over adolescence may not generalize to other age groups. The use of PCA in younger and older age groups would be an interesting expansion of the work presented here.