mne.beamformer.lcmv_epochs

mne.beamformer.lcmv_epochs(epochs, forward, noise_cov, data_cov, reg=0.05, label=None, pick_ori=None, return_generator=False, picks=None, rank=None, verbose=None)[source]

Linearly Constrained Minimum Variance (LCMV) beamformer.

Compute Linearly Constrained Minimum Variance (LCMV) beamformer on single trial data.

Note

This implementation has not been heavily tested so please report any issue or suggestions.

Parameters:

epochs : Epochs

Single trial epochs.

forward : dict

Forward operator.

noise_cov : Covariance

The noise covariance.

data_cov : Covariance

The data covariance.

reg : float

The regularization for the whitened data covariance.

label : Label

Restricts the LCMV solution to a given label.

pick_ori : None | ‘normal’ | ‘max-power’

If ‘normal’, rather than pooling the orientations by taking the norm, only the radial component is kept. If ‘max-power’, the source orientation that maximizes output source power is chosen.

return_generator : bool

Return a generator object instead of a list. This allows iterating over the stcs without having to keep them all in memory.

picks : array-like of int

Channel indices to use for beamforming (if None all channels are used except bad channels).

rank : None | int | dict

Specified rank of the noise covariance matrix. If None, the rank is detected automatically. If int, the rank is specified for the MEG channels. A dictionary with entries ‘eeg’ and/or ‘meg’ can be used to specify the rank for each modality.

verbose : bool, str, int, or None

If not None, override default verbose level (see mne.verbose() and Logging documentation for more).

Returns:

stc: list | generator of (SourceEstimate | VolSourceEstimate)

The source estimates for all epochs

See also

lcmv_raw, lcmv

Notes

The original reference is: Van Veen et al. Localization of brain electrical activity via linearly constrained minimum variance spatial filtering. Biomedical Engineering (1997) vol. 44 (9) pp. 867–880

The reference for finding the max-power orientation is: Sekihara et al. Asymptotic SNR of scalar and vector minimum-variance beamformers for neuromagnetic source reconstruction. Biomedical Engineering (2004) vol. 51 (10) pp. 1726–34