Abstract
The dominant frequency of neural oscillations of the occipital, adult human brain is 8-12 Hz, denoted as the alpha frequency (Berger, 1929). These rhythms have been implicated in aspects of vision, specifically temporal processing (Samaha & Postle, 2015). In infants, a functional and topographical analog of the adult alpha rhythm was identified, but with a lower frequency range (Stroganova et al. 1999). While it is accepted that alpha increases over development, there is little work directly on the issue, and the precise developmental trajectory of peak alpha frequency (PAF) remains unclear. A more precise tracking will help constrain theories, specifically whether changes in PAF may underlie changes in temporal processing (Freschl et al., 2019, 2020). We conducted a meta-analysis to evaluate the development of PAF from infancy to adolescence (PAF, the frequency that exhibits maximum power within the alpha range, gives a more precise measure than band-power). Our abstract triage (keywords such as EEG, alpha, development, and typical) yielded 722 studies, and 378 met our criteria (i.e., reported occipital resting PAF in a typical population) for review. Each paper was reviewed by two trained members to ensure reliability. After full-text review, 35 studies were deemed relevant and PAF, along with other relevant information, was extracted for analysis. We conducted an asymptotic nonlinear regression on PAF as a function of age. This analysis revealed an increase in PAF from infancy (reaching 6.4 Hz at 6 months to 7.5 Hz at 36 months) to adolescence (reaching 9.4 Hz at 10 years to 10.3 Hz at 18 years), with an asymptote at 10.8 Hz, matching adult levels. These results pin down the precise developmental trajectory of PAF, which is consistent with our behavioral measures of the development of visual temporal processing (Freschl et al., 2019, 2020).