Novel ⁴He-OPMs support waveform-specific beta burst analysis comparable to SQUID-MEG

Studying the electrophysiology of motor preparation and execution is challenging due to the restrictions often placed on the experimental paradigm by the imaging modality. MEG is well suited to track temporal brain dynamics while offering good spatial resolution, but requires an absence of head motion due to the fixed helmet and associated cryogenic cooling system. Here, we tested whether novel, room temperature, wearable optically pumped magnetometers using Helium can support waveform-specific beta burst analysis in a visuomotor task, compared directly with SQUID-MEG. Beta band activity (13-30 Hz) is widely associated with motor activity, and understood to occur in bursts rather than sustained oscillations. Here, we used a novel beta burst waveform extraction pipeline to quantify both burst occurrence over time and the modulation of specific burst waveform motifs. We find that particular waveform classes show robust task-relevant modulations of burst rate. Critically, burst waveform shapes and their waveform-specific rate modulations were highly similar for Helium-OPMs and SQUID-MEG data, despite modality differences in overall time-frequency characteristics. These results validate Helium-OPMs for waveform-specific beta burst analysis, and support their use for high-quality electrophysiology in less restricted paradigms.