Magnetencephalography is a non-invasive, neurophysiological method which is able to measure magnetic fields induced by neural activity in the brain. The magnetic field passes the brain tissue and can be detected by sensors outside of the brain. MEG is a non-invasive method with the primary use to measure time courses of activity. However, in contrast to fMRI it allows a high temporal resolution. In comparison with EEG, which is sensitive to activity in more brain areas, MEG allows a more accurate localization.

Contraindications - Who can not participate?

To avoid magnetic interactions – especially with metals – because they reduce the measurement accuracy, no metals should be worn on your body during the measurements. Because of that, before entering into the MEG room you have to speak with the researchers about any possible constraints which limit your participation in the study (e.g., if you have any kind of implants).

Please take the following points into account:

• It is not allowed to enter the MEG with any electronically controlled devices such as pacemakers, neuro-stimulators, insulin pumps or hearing devices.
• Only enter the MEG when all metallic objects are discarded (e.g., keys, glasses, belts, …).
• Metallic implants also have the possibility to be ferro magnetic. The researcher needs to be informed about all known or possible implants prior to the measurement.
• Tattoos (also permanent make-up) can contain color particles with metallic parts in it. Please inform the researcher if you have a tattoo. 
• Also cosmetics such as mascaras, rouge or even styling gel can contain metal. Please avoid using those on the day of measurement.
• If you need any glasses, if it is possible, please wear lenses, at the day of the measurement.

Procedure

Before starting the MEG measurement, your head will be measured via electromagnetic markers to find the exact position of your head within the MEG. This is totally painless and harmless. The real MEG, measurement will take about one hour and is separated in some blocks. The exact procedure will be explained to you by the researcher.

During the measurement, the researcher is in the neighboring room and will be in contact with you via a two-way intercom. In addition, there is a camera which is connected with a monitor in the experimenter’s room. The transferred video will not be stored.