Development of Occipital Peak Alpha Frequency: a Meta-Analysis

• In Event: Poster Session 13
  In Poster Session: PS 13 Topic - Biological Processes: Neuroscience and Genetics

Abstract

Brain rhythms measured from an electroencephalogram (EEG), fall into frequency bands emerging from different brain regions and functional states (Berger 1924). Early EEG investigations, in adults, documented a dominant 10 Hz frequency, most prominent in the occipital region, which was labeled as alpha (Berger 1929). Over development, it has been argued that the alpha range is initially lower and gradually increases, from 3-5 Hz frequency at 3 months of age, to 6-9 Hz within the first year of life (Saby & Marshall, 2012), based on functional (prominent during eyes closed resting state) and topographical (prominent in the occipital region) correspondence to adult rhythms (Stroganova et al 1999; Bell & Cuevas 2012).

Occipital alpha oscillations have been associated with a state of attentional disengagement in which limiting visual input results in an increase in alpha in both infants and adults (Stroganova et al. 1999). And, more recently, alpha rhythms have been implicated in various aspects of visual processing such as the organization of visual input across time (Samaha et al. 2015; Clayton et al. 2018). Previous studies measuring developmental changes in alpha oscillations have focused only on differences in overall alpha power between age groups, or comparisons of overall alpha power to power in other bands (e.g. theta or delta) (Saby & Marshall, 2012). However, critical developmental changes may occur within a frequency band (Marshall et al. 2002). Peak alpha frequency (PAF), the frequency within the alpha range that exhibits maximum power, gives us a more precise measure of age-related changes than overall power (Cragg et al. 2011; Dickinson et al. 2018).

There have only been a handful of studies explicitly measuring developmental changes in PAF, and these have used a wide range of methods, populations, age groups, and analyses. Here, we plan to conduct a meta-analysis to systematically track the development of resting state PAF from infancy to adolescence. In preparation, we conducted a PubMed search (including key terms such as development, alpha, typical, and EEG), yielding 722 potentially relevant studies. After completion of an initial abstract triage, we narrowed evaluation to 378 studies. A pair of trained team members each evaluated whether a paper was indeed relevant (i.e., reported occipital, resting state PAF in a typical child population). After this full-text review, we identified 35 studies that met our full criteria for inclusion. From these, we plan to extract average occipital PAF per age group(s), along with other relevant variables (including context (e.g., eyes open versus eyes closed), recording channel(s), and sex breakdown). Using the group occipital PAF from each study, we will conduct a weighted (by sample size) nonlinear regression. We plan to complete data analysis by December 2020. We hypothesize a developmental increase in PAF, from infancy to adolescence. This more reliable, precise trajectory will help constrain theories that link alpha rhythms to the development of cognitive and perceptual processes (e.g. Freschl et al., 2019).

Authors

• Julie Freschl, University of Massachusetts Boston
  Presenting Author

• Lina Al Azizi, University of Massachusetts Boston
  Non-Presenting Author

• Lilyann Balboa, University of Massachusetts Boston
  Non-Presenting Author

• Zsuzsa Kaldy, University of Massachusetts Boston
  Non-Presenting Author

• Erik Blaser, University of Massachusetts Boston
  Non-Presenting Author