conpy.connectivity.dics_connectivity#
- conpy.connectivity.dics_connectivity(vertex_pairs, fwd, data_csd, reg=0.05, coh_metric='absolute', n_angles=50, block_size=10000, n_jobs=1, verbose=None)[source]#
Compute spectral connectivity using a DICS beamformer.
Calculates the connectivity between the given vertex pairs using a DICS beamformer [1] [2]. Connectivity is defined in terms of coherence:
C = Sxy^2 [Sxx * Syy]^-1
Where Sxy is the cross-spectral density (CSD) between dipoles x and y, Sxx is the power spectral density (PSD) at dipole x and Syy is the PSD at dipole y.
- Parameters:
- vertex_pairspair of lists (vert_from_idx, vert_to_idx)
Vertex pairs between which connectivity is calculated. The pairs are specified using two lists: the first list contains, for each pair, the index of the first vertex. The second list contains, for each pair, the index of the second vertex.
- fwdinstance of Forward
Subject’s forward solution, possibly restricted to only include vertices that are close to the sensors. For ‘canonical’ mode, the orientation needs to be tangential or free.
- data_csdinstance of CrossSpectralDensity
The cross spectral density of the data.
- regfloat
Tikhonov regularization parameter to control for trade-off between spatial resolution and noise sensitivity. Defaults to 0.05.
- coh_metric‘absolute’ | ‘imaginary’
The coherence metric to use. Either the square of absolute coherence (‘absolute’) or the square of the imaginary part of the coherence (‘imaginary’). Defaults to ‘absolute’.
- n_anglesint
Number of angles to try when optimizing dipole orientations. Defaults to 50.
- block_sizeint
Number of pairs to process in a single batch. Beware of memory requirements, which are
n_jobs * block_size
. Defaults to 10000.- n_jobsint
Number of blocks to process simultaneously. Defaults to 1.
- verbosebool | str | int | None
If not None, override default verbose level (see
mne.verbose()
and Logging documentation for more).
- Returns:
- connectivityinstance of Connectivity
The adjacency matrix.
See also
all_to_all_connectivity_pairs
Obtain pairs for all-to-all connectivity.
one_to_all_connectivity_pairs
Obtain pairs for one-to-all connectivity.
References
[1]Gross, J., Kujala, J., Hamalainen, M., Timmermann, L., Schnitzler, A., & Salmelin, R. (2001). Dynamic imaging of coherent sources: Studying neural interactions in the human brain. Proceedings of the National Academy of Sciences, 98(2), 694–699.
[2]Kujala, J., Gross, J., & Salmelin, R. (2008). Localization of correlated network activity at the cortical level with MEG. NeuroImage, 39(4), 1706–1720.