Our Magnetoencephalography (MEG) laboratory is equipped with the latest whole head 306 channels Elekta Neuromag MEG TRIUX system. MEG is a modern non-invasive neurophysiological technique for measuring magnetic fields generated by neuronal activities inside the brain. The MEG activity is acquired by an array of superconducting quantum interference devices (SQUIDs) placed close to the scalp which is capable of measuring magnetic fields on the femtotesla (fT) scale. Since the signal from the brain is too weak (~ 10-13 T) compared to the ambient magnetic noise in an urban environment (~ 10-7 T), MEG needs a special shielding from external magnetic signal. For this purpose, our MEG system is housed in a magnetic shielded room (MSR) for reducing noise from the surrounding environment.
We offer several techniques for brain stimulation and analysis that allow us to obtain better results and guarantee a good service for both research and clinical applications. Our MEG services can be booked using our NIFBM Booking System, which will soon be made available here.
Our lab is equipped with an MEG compatible BrainCap of 128 high-quality Ag/AgCl EEG electrodes from Brain Products GmbH. Electrodes are fixed to the cap and extremely flat which makes BrainCap very comfortable for the subject (e.g. avoiding excessive pressure onto the scalp, even in sleep studies during which the subject lies on the electrodes). All EEG electrodes are buttoned directly into the cap (total height 3.5 mm) or can be attached to the skin with washers. This device facilitates concurrent MEG-EEG recording that allows an effective measurement of the brain activity.
Earphone for Auditory stimulation
Auditory stimulation is provided using an earphone, which is especially designated for MEG applications. The stimuli are provided using stimulation programs that are installed in the STIM computer (STIM2) outside the MSR. The stimuli are applied with high precision having an extremely small delay of less than 20 milliseconds.
Visual stimulation is provided from the STIM computer through a Panasonic projector model PT-DS12KE (placed outside the MSR) projected onto a MEG compatible Elekta screen located inside the MSR. This allows a clear representation of the different scenarios of visual stimuli tasks, while keeping the image presentation delay shorter than 50 milliseconds.
Electrical non-harmful stimulation is provided with small foam pads to stimulate instantaneously the median nerve on the Left/Right wrist. This stimulation will cause the thumbs to twitch and a trigger which is simultaneously recorded with the MEG signal.
Motor or response pads
We also have MEG compatible motor or response pads. Volunteers/patients will be asked to finger-tap the motor pad for performing Magnetic Evoked Field (MEF) tests. These pads can also be used as a response button for cognitive tasks.