Performance of optically pumped magnetometer magnetoencephalography: validation in large samples and multiple tasks

Abstract Objective
Current commercial magnetoencephalography (MEG) systems detect neuro-magnetic signals using superconducting quantum interferometers devices (SQUIDs), which require liquid helium as cryogen and have many limitations during operation. In contrast, optical pumped magnetometers (OPMs) technology provides a promising alternative to conventional SQUID-MEG. OPMs can operate at room temperature, offering benefits such as flexible deployment and lower costs. However, the validation of OPM-MEG has primarily been conducted on small sample sizes and specific regions of interest in the brain, lacking comprehensive validation for larger sample sizes and assessment of whole-brain. 
Approach
We recruited 100 participants, including healthy and neurological disorders individuals. Whole-brain OPM-MEG and SQUID-MEG data were recorded sequentially during auditory (n = 50) and visual (n = 50) stimulation experiments. By comparing the task-evoked responses of the two systems, we aimed to validate the performance of the next-generation OPM-MEG. 
Main results
The results showed that OPM-MEG enhanced the amplitude of task-related responses and exhibited similar magnetic field patterns and neural oscillatory activity as SQUID-MEG. There was no difference in the task-related latencies measured by the two systems. The signal-to-noise ratio was lower for the OPM-MEG in the auditory experiment, but did not differ in the visual experiment, suggesting that the results may be task-dependent. 
Significance
These results demonstrate that OPM-MEG, as an alternative to traditional SQUID-MEG, shows superior response amplitude and comparable performance in capturing brain dynamics. This study provides evidence for the effectiveness of OPM-MEG as a next-generation neuroimaging technique.