Developmental changes in occipital alpha rhythms: Recording EEG during public engagement events

Statistical power in cognitive neuroscience experiments is often very low. Low sample size can reduce the likelihood of detecting real effects (false negatives) and increase the risk of detecting non-existing effects by chance (false positives). Here we present a study investigating a relatively unexplored method of increasing the sample size for simple electroencephalography (EEG) studies, of recording EEGs in the community during public engagement and outreach events. We collected data from 346 participants (189 females, age range 6-76 years) over 6 days, totalling 29 hours, at local science festivals. Occipital alpha activity (6-15 Hz) was recorded for 30 seconds using a single-channel electrode placed on the occipital midline (location Oz) while participants rested with their eyes closed. Using this community-based approach, we identified age-related changes in individual alpha frequency (IAF) and alpha power within a cross-section of the population. IAF increased throughout childhood, reaching a peak frequency in people in their early 20s, and slowed again in middle and older age. Alpha power reduced linearly with advancing age, but after accounting for aperiodic signal there was no reduction in alpha power over the lifespan. There were no associations between these EEG indices and self-reported fatigue, as measured by the Multidimensional Fatigue Inventory. Finally, we present a set of recommendations for researchers who wish to collect behavioural and EEG data within public engagement and outreach environments.