MEG Lab

Our newest facility, the Magnetoencephalography Laboratory opened in the summer of 2024. This lab houses the latest generation of magnetic sensors (known as optically pumped magnetometers or OPMs) in a state-of-the-art magnetically-shielded room (MSR) that prevents external environmental interference. An array of 64 OPMs around the participant’s head detects minute changes in magnetic fields at the scalp caused by neural activity.

Technical Details

The PNI Scully Center’s MEG Lab houses a 64-sensor triaxial optically pumped magnetometer (OPM) MEG system (Cerca Magnetics Ltd) mounted in a 3D-printed semi-flexible helmet. The laboratory provides multiple helmet sizes to accommodate adults and children. Each OPM sensor, approximately the size and shape of a lego brick, operates on the principle of quantum mechanics. It consists of a vapor cell containing alkali metal atoms that are optically pumped by laser light to align their magnetic moments. If there is an external magnetic field (such as the small magnetic fields generated by neural activity at the surface of our scalps), the magnetic moments of the atoms change and affect the amount of laser light transmission. By measuring the changes in light transmission, we can detect and measure the strength of the external magnetic fields generated by brain activity.

The OPM sensors can detect very small magnetic fields at the scalp, but only if the sensors are in a zero magnetic field environment. To create such an environment, the participant is placed in a magnetically-shielded room (MSR). The room is shielded from magnetic fields from nearby equipment or infrastructure and its walls are equipped with special coils to null the remnant background magnetic field that remains. The MSR is equipped with a comfortable chair and footrest for the participant, as well as a collection of peripheral equipment not unlike what one finds at the MRI Facility or EEG Laboratory.

PNI researchers interested in obtaining more detailed information regarding our MEG Lab should visit our internal Scully Facilities Wiki.