mne.channels.fix_mag_coil_types

mne.channels.fix_mag_coil_types(info, use_cal=False)

Fix magnetometer coil types.

Parameters

infomne.Info

The mne.Info object with information about the sensors and methods of measurement. Corrections are done in-place.

use_calbool

If True, further refine the check for old coil types by checking info['chs'][ii]['cal'].

Notes

This function changes magnetometer coil types 3022 (T1: SQ20483N) and 3023 (T2: SQ20483-A) to 3024 (T3: SQ20950N) in the channel definition records in the info structure.

Neuromag Vectorview systems can contain magnetometers with two different coil sizes (3022 and 3023 vs. 3024). The systems incorporating coils of type 3024 were introduced last and are used at the majority of MEG sites. At some sites with 3024 magnetometers, the data files have still defined the magnetometers to be of type 3022 to ensure compatibility with older versions of Neuromag software. In the MNE software as well as in the present version of Neuromag software coil type 3024 is fully supported. Therefore, it is now safe to upgrade the data files to use the true coil type.

Note

The effect of the difference between the coil sizes on the current estimates computed by the MNE software is very small. Therefore the use of fix_mag_coil_types is not mandatory.

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