What is MEG?Magnetoencephalography (MEG) works by detecting the magnetic fields created by the brain's electric signals. These fields are a billion times smaller than the Earth's magnetic field, so MEG has to be carried out in a heavily shielded room - often in the dead of night, when other electrical devices are switched off. The person sits inside a 'helmet' of special sensors that detect the tiny magnetic signals produced by the brain.
MEG: the future?
MEG can be combined with scanning techniques to build up a detailed picture of a living, working brain and could be used in the future for virtual reality brain surgery. In particular, MEG can provide accurate information about the cortex (the outer layer of the brain) because it doesn't respond to electric signals coming from deep within the brain, unlike an EEG. MEG also 'sees through' the skull and scalp, which can interfere with EEGs.