Magnetoencephalography (MEG) is a non-invasive method for recording cortical activity which boasts exceptional temporal and fine spatial resolution. It is used to map brain activity by recording magnetic fields produced by the electrical currents neurons generate when they communicate with each other.
Thanks to the excellent temporal and spatial resolution of MEG, we can determine when and what particular region of the brain has been activated. This is critical for understanding how language abilities are implemented in the brain and the relationships between brain structures and their functions.
The MEG facility at the BCBL is a 306-sensor (204 planar gradiometers and 102 magnetometers; arranged in a helmet configuration) Elekta Neuromag® device with 16 digital trigger lines and 8 auxiliary analog input channels. This setup allows to deliver both auditory and visual stimuli, and recordings can be performed with the participant in either a supine or sitting position. The MEG device also includes an integrated 64-channel EEG system (60 single channels and 4 differential electrodes) for simultaneous MEG and EEG recording that can be acquired at a sampling rate of up to 8 kHz (5 kHz standard) in either AC or DC.
The facility at the BCBL includes passive shielding to reduce external noise, as well as MaxFilter™ software, which filters artifacts as well as internal and external noise sources. For data analysis, the Elekta Neuromag® includes advanced analysis software, including powerful tools for visualization and source modeling of recorded data.