Brief overview of the modality
The magnetoencephalography (MEG) laboratory houses a Neuromag TRIUX system installed 2018. MEG allows for continuous recordings of ongoing brain activity with a millisecond time resolution. By using advanced analysis tools it is furthermore possible to identify where in the brain the measured electrophysiology activity is generated.
The TRIUX system has 306 sensors distributed over the head: 204 planar gradiometers and 102 magnetometers (noise-resilient ARMOR sensors). The MEG system is place in a shielded room (2 layers of mu-metal and 1 layer of aluminium). The system allows for concurrent EEG recordings from 64 electrodes and as well as bipolar sensors. The system also allows for continuous monitoring of the head position. A closed-loop He recycler fully eliminates refills.
The peripherals of the MEG system include:
- ProPixx visual projector (1440 Hz refresh rate)
- SOUNDPixx auditory stimulation
- EyeLink 1000 Plus fast eye-tracker
- Digitimer DS7A stimulator
- NAtA button boxes
- EASYCAP EEG caps (64 channels)
- Stimulus delivery computer (Psychtoolbox, PsychoPy, ePRIME and Presentation)
For data analysis we primarily rely on the FieldTrip toolbox and MNE Python. We have developed a local data analysis pipeline.
What research data is produced and what can we understand from this?
The MEG system records ongoing brain activity from humans subjects performing cognitive tasks. The tasks we use include attention, memory, sleep and language comprehension. This allows for characterizing the braindynamics – such as neuronal oscillations – associated with a given cognitive function. MEG records the brain activity with a millisecond time-resolution and source modelling approaches allows for localizing where in the brain the activity is activated. As such MEG is an excellent tool for studying the networks engaged in the working brain. Researchers at the CHBH have strong expertise on investigated the role of neuronal oscillations.
The MEG system is used for conducting fundamental research on cognition as well as to investigate brain dynamics associated with neurological and psychiatric disorders. The data from the MEG system are complementary to data from other techniques housed in the CHBH. Therefore, we are integrating the MEG research using other techniques as for instance brain stimulation, functional MRI and measures of structural connectivity. The research conducted on the MEG system is done is spirit of open science and we strive to co-register new studies and make our approaches and data freely available.