This dataset was obtained from The Open MEG Archive (OMEGA, https://omega.bic.mni.mcgill.ca).

You are free to use all data in OMEGA for research purposes; please aknowledge its authors and cite the following reference in your publications if you have used data from OMEGA: 

Niso G, Rogers C, Moreau JT, Chen LY, Madjar C, Das S, Bock E, Tadel F, Evans A, Jolicoeur P, Baillet S. OMEGA: The Open MEG Archive. Neuroimage. 2015; Available from: http://dx.doi.org/10.1016/j.neuroimage.2015.04.028



DESCRIPTION

# Experiment

    - 5 subjects x 5 minute resting sessions, eyes open 


# MEG acquisition

    - Acquisition at 2400Hz, with a CTF 275 MEG system,
    - Recorded at the Montreal Neurological Institute in 2012-2016.
    - Anti-aliasing low-pass filter at 600Hz, files may be saved with or without the CTF 3rd order gradient compensation.
    - Recorded channels (at least 297):
        * 26 MEG reference sensors (#2-#27)
        * 270 MEG axial gradiometers (#28-#297)
        * 1 ECG bipolar (EEG057/#298) - Not available in the empty room recordings
        * 1 vertical EOG bipolar (EEG058/#299) - Not available in the empty room recordings
        * 1 horizontal EOG bipolar (EEG059/#300) - Not available in the empty room recordings 
  

# Head shape and fiducial points

    - 3D digitization using a Polhemus Fastrak device driven by Brainstorm. The .pos files contain:
        * The center of the CTF coils,
        * The anatomical references we use in Brainstorm: nasion and ears as illustrated here,
	* Around 100 head points distributed on the hard parts of the head (no soft tissues). 


# Subject anatomy

    - Structural T1 image (defaced for anonymization purposes)
    - Processed with FreeSurfer 5.3
    - The anatomical fiducials (NAS, LPA, RPA) have already been marked and saved in the files fiducials.m 




The data in this dataset has been organized according to the BIDS specifications (Brain Imaging Data Structure, http://bids.neuroimaging.io) 


Release history:
2016-12-01: initial release
