mne.preprocessing.compute_bridged_electrodes(inst, lm_cutoff=16, epoch_threshold=0.5, l_freq=0.5, h_freq=30, epoch_duration=2, bw_method=None, verbose=None)[source]#

Compute bridged EEG electrodes using the intrinsic Hjorth algorithm.

First, an electrical distance matrix is computed by taking the pairwise variance between electrodes. Local minimums in this matrix below lm_cutoff are indicative of bridging between a pair of electrodes. Pairs of electrodes are marked as bridged as long as their electrical distance is below lm_cutoff on more than the epoch_threshold proportion of epochs.

Based on [1][2][3] and the EEGLAB implementation.

instinstance of Raw, Epochs or Evoked

The data to compute electrode bridging on.


The distance in \({\mu}V^2\) cutoff below which to search for a local minimum (lm) indicative of bridging. EEGLAB defaults to 5 \({\mu}V^2\). MNE defaults to 16 \({\mu}V^2\) to be conservative based on the distributions in Greischar et al.[2].


The proportion of epochs with electrical distance less than lm_cutoff in order to consider the channel bridged. The default is 0.5.


The low cutoff frequency to use. Default is 0.5 Hz.


The high cutoff frequency to use. Default is 30 Hz.


The time in seconds to divide the raw into fixed-length epochs to check for consistent bridging. Only used if inst is The default is 2 seconds.


bw_method to pass to scipy.stats.gaussian_kde.

verbosebool | str | int | None

Control verbosity of the logging output. If None, use the default verbosity level. See the logging documentation and mne.verbose() for details. Should only be passed as a keyword argument.

bridged_idxlist of tuple

The indices of channels marked as bridged with each bridged pair stored as a tuple.

ed_matrixndarray of float, shape (n_epochs, n_channels, n_channels)

The electrical distance matrix for each pair of EEG electrodes.


New in v1.1.


Examples using mne.preprocessing.compute_bridged_electrodes#

Identify EEG Electrodes Bridged by too much Gel

Identify EEG Electrodes Bridged by too much Gel