The dual future of OPM-MEG: Clinical translation and naturalistic neuroscience

Optically pumped magnetometer magnetoencephalography (OPM-MEG) has moved beyond proof of principle. The decisive question is no longer whether cryogen-free sensors can detect neuromagnetic fields from the human brain with sufficient sensitivity, but whether complete systems can deliver clinical decision value and interpretable recordings during more naturalistic behaviour. Here we argue that OPM-MEG is developing along two partly overlapping trajectories. One is clinical translation, where usefulness depends more on reliable workflows, calibrated source localisation, auditable quality control, and empirical evidence for improved diagnostic or treatment decisions. The other is naturalistic neuroscience, where wearable measurement can connect neural dynamics to movement, action, and social behaviour without conflating neural activity with movement-related artefacts. Both trajectories depend on a shared engineering stack including magnetic field control, dense spatial sampling, accurate calibration, integrated electronics, artefact suppression, participant comfort, and synchronised behavioural measurement. The next stage of OPM-MEG should be evaluated by clinical utility in specific patient groups, statistically identifiable neural dynamics in behaviourally rich settings, and sufficient system detail for replication across systems and sites.