High-frequency broadband activity detected noninvasively in infants distinguishes wake from sleep states

High-frequency broadband activity (HFB) indexes local brain activity generated by neurons, but has been limited to invasive measures due to high-frequency signal drop off through the skull. Using scalp EEG, we reveal that HFB distinguishes wake from sleep states in infants with 90% reliability. The presence of thin skull and soft spots (fontanelles) between skull plates that have not yet fused creates the environment needed for HFB detection in infants using noninvasive measures, paving the way to study the infant brain across research and clinical settings.

Our research aims to uncover mechanistic explanations of the neural basis of human behavior, that is, move from where to how. Our goals are multifaceted: (1) advance fundamental science by discovering new knowledge using rigorous, reproducible methods; and (2) advance translational applications in neurotechnology, precision medicine, and product development that are grounded in rigorous science. In this project, we showcase how a new, innovative yet straightforward approach - capitalizing on a representative sample and treating scalp EEG data like intracranial EEG data - can solve an old problem. In so doing, we opened a window into the mysterious black box that is the infant brain.

These scripts produce the results reported in:

• Holubecki, AM, Yarbrough, JB, Rangarajan, V, Kuperman, R, Knight, RT, Johnson, EL. High-frequency broadband activity detected noninvasively in infants distinguishes wake from sleep states. bioRxiv (2025). DOI

Project data are available on OSF. These data have been prepared for analysis as described in the publication.

Publications or other papers using these scripts and/or data should cite the publication above.

Software:

• MATLAB 9.7 (last tested with R2024b)
  • Set General > MAT-Files > save -v7.3
• Fieldtrip (last tested with fieldtrip-20250114) - download

Notes:

• Open and run the batch script (run_batch) to run through all scripts and reproduce the published results.