Re-reference selected channels using a bipolar referencing scheme.
A bipolar reference takes the difference between two channels (the anode
minus the cathode) and adds it as a new virtual channel. The original
channels will be dropped.
Multiple anodes and cathodes can be specified, in which case multiple
virtual channels will be created. The 1st anode will be subtracted from the
1st cathode, the 2nd anode from the 2nd cathode, etc.
By default, the virtual channels will be annotated with channel info of
the anodes, their locations set to (0, 0, 0) and coil types set to
EEG_BIPOLAR.
Parameters: |
- inst : instance of Raw | Epochs | Evoked
Data containing the unreferenced channels.
- anode : str | list of str
The name(s) of the channel(s) to use as anode in the bipolar reference.
- cathode : str | list of str
The name(s) of the channel(s) to use as cathode in the bipolar
reference.
- ch_name : str | list of str | None
The channel name(s) for the virtual channel(s) containing the resulting
signal. By default, bipolar channels are named after the anode and
cathode, but it is recommended to supply a more meaningful name.
- ch_info : dict | list of dict | None
This parameter can be used to supply a dictionary (or a dictionary for
each bipolar channel) containing channel information to merge in,
overwriting the default values. Defaults to None.
- copy : bool
Whether to operate on a copy of the data (True) or modify it in-place
(False). Defaults to True.
- verbose : bool, str, int, or None
If not None, override default verbose level (see mne.verbose()
and Logging documentation for more).
|
Returns: |
- inst : instance of Raw | Epochs | Evoked
Data with the specified channels re-referenced.
|
Notes
- If the anodes contain any EEG channels, this function removes
any pre-existing average reference projections.
- During source localization, the EEG signal should have an average
reference.
- The data must be preloaded.