Do age-related differences in aperiodic neural activity explain differences in resting EEG alpha?

Ashley Merkin, Sabrina Sghirripa, Lynton Graetz, Ashleigh E. Smith, Brenton Hordacre, Richard Harris, Julia Pitcher, John Semmler, Nigel C. Rogasch, Mitchell Goldsworthy

Research output: Contribution to journalArticlepeer-review

Abstract

Alpha-band oscillatory activity in human electroencephalography (EEG) becomes slower and lower in amplitude with advanced age. However, the influence of aperiodic activity on these measures has received little consideration. We investigated whether age-related differences in aperiodic activity explains differences in resting EEG peak alpha frequency and power. We assessed aperiodic activity in 85 younger and 92 older adults by fitting the 1/f-like background activity evident in EEG power spectra using the spectral parameterization (“specparam”) algorithm. Across the scalp, the aperiodic exponent and offset were smaller in older compared to younger participants, reflecting a flatter 1/f-like slope and a downward broadband shift in power spectra with age. After correcting for aperiodic activity, peak alpha frequency remained slower in older adults; however, peak alpha power no longer differed statistically between age groups. The large sample size utilized in this study, as well as the depth of analysis, provides further evidence that the aperiodic component of the resting EEG signal is altered with aging and should be considered when investigating neural oscillatory activity.

Original languageEnglish
Pages (from-to)78-87
Number of pages10
JournalNeurobiology of Aging
Volume121
DOIs
Publication statusPublished or Issued - Jan 2023

Keywords

  • 1/f
  • Age
  • Alpha
  • Aperiodic
  • Electroencephalography
  • Oscillations

ASJC Scopus subject areas

  • Neuroscience(all)
  • Ageing
  • Clinical Neurology
  • Developmental Biology
  • Geriatrics and Gerontology

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