Recent Advances in Magnetoencephalography

Abstract

The review of novel advances in the magnetoencephalography (MEG) technique is present, including the development of optically pumped magnetometers (OPM) which are very promising for brain-computer interfaces (BCIs). The main advantage of OPMs over conventional SQUID devices is that they do not require cryogenic cooling, that decreases their price by 2–3 times. Moreover, the OPMs can be placed within millimeters from the scalp, that approximately doubles the signal-to-noise ratio. In addition, they are not so susceptible to muscle artefacts as EEG. In addition, the location of OPMs in a field-nulling apparatus decreases the influence of artefacts caused by head movement in the ambient field. All these advantages give potential possibilities to develop a new generation of OPM-based BCIs, cheaper, more flexible and sensitive than SQUID-based BCIs, which can serve for both motor and non-motor tasks. Despite the enormous progress made in the past few years, OPM–MEG is so far a developing technology that needs further improvement. Due to their large size, the number of channels is relatively small and therefore they cannot cover the entire head. The miniaturization and universality of lightweight helmets would be an essential step towards further development of OPM wearable for BCI applications.