Visual gamma oscillations in 1- to -5-year-old children using OPM-MEG

Poster Session E - Monday, April 15, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Julie Sato¹ (julie.sato@sickkids.ca), Marlee Vandewouw^1,2, Kaela Amorim¹, Kristina Safar¹, Margot Taylor^1,2; ¹The Hospital for Sick Children, ²University of Toronto

Gamma oscillations play an important role in cortical information processing and cognition, including visual perception and attention. Little is known, however, about the early development of gamma due to limitations with recording high frequency gamma signals in electroencephalography or testing young children in conventional magnetoencephalography (MEG) systems. Optically pumped magnetometers (OPMs) are a novel, wearable MEG system that can be adapted to fit smaller head sizes suitable for paediatric participants and provide the means to measure MEG signals in young children, including high fidelity gamma band activity. The present study is the first to investigate visual gamma-band responses in 1-5-year-old children using a whole-head OPM-MEG system and includes data collected and analyzed after December 2023. OPM data were recorded in 51 children (23 males, Mage=3.23 years) while they viewed oscillating concentric circles known to induce gamma-band oscillations, which reflect cortical excitation and inhibition (E-I). Data were epoched and filtered to broad gamma-band (25-80Hz) and beamformed to reconstruct source activity. Our analyses showed a significant positive association between low and high gamma-band amplitude with age in the visual cortex. Averaged time frequency spectrograms for each, one-year age-range also showed an increase in gamma relative to baseline, most prominently in the 5-year-olds. These findings are the first to use the OPM-MEG system in young children to investigate gamma-band responses. These preliminary results suggest that gamma could be a useful metric of E-I imbalance, which will be foundational to our understanding of typical and atypical developmental trajectories of brain function during early childhood.

Topic Area: PERCEPTION & ACTION: Development & aging