elephant-data/unittest/phase_analysis/weighted_phase_lag_index

Weighted Phase Lag Index

see [1] for further information about the measure

This license CC BY 4.0 covers the artificial LFP-data and calculated ground truth data. \ This license BSD-3 covers the provided script codes.

Description

This folder contains subfolders for:

• 1. the WPLI related artificial LFP datasets in 'wpli_specific_artificial_data'
• 2. the ground truth data calculated by 'ft_connectivity_wpli' function from MATLAB package FieldTrip (see [2] ) in 'ground_truth_wpli'
• 3. the scripts used for calculating the ground truth, slicing the R2G-data and creating the artificial LFP-data in 'scripts'.

NOTE: *.mat files can't contain units, there for we provide the units explicitly

The _artificialLFPs{i}.mat_ files in 'wpli_specific_artificial_data' contain the artificial LFP-signals with the fields:

• 'lfp_matrix': multi-trial LFP-data with shape (150(trials) x 2500(samples); implicit unit: uV)
• 'times': time-vector (1 (aligned trials) x 2500 (time-points); implicit unit: msec)
• 'sf': sampling frequency of the recording (1000; implicit unit: Hz)

There is also a _cross_spectrum_of_artificial_LFPs_1_and2.mat file containing the cross-spectrum of signal 1 and 2 with the fields:

• 'cross_spectrum_matrix': multi-trial cross-spectrum with shape (150(trials) x 1251(cross-spectrum))
• 'frequencies': positive, real-valued frequencies with shape (1 (aligned trials) x 1251 (frequency); implicit unit: Hz)
  

The *.csv files in 'ground_truth_wpli' contain the function-dependent ground truths calculated by
the reference implementation:

• data-shapes:

  • real data: 1 (aligned trials) x 1051 (WPLI values)
  • artificial data: 1 (aligned trials) x 1251 (WPLI values)
    

• For WPLI the reference implementation is ft_connectivity_wpli() from the MATLAB package 'FieldTrip' (see [1] for the reference method publication and [2] for the toolbox publication). \ Used versions of MATLAB & FieldTrip:\ MATLAB Version 9.9 (2020b)\ FieldTrip fieldtrip-20210128

References

1. Vinck, Martin et al. “An improved index of phase-synchronization for electrophysiological data in the presence of volume-conduction, noise and sample-size bias.” NeuroImage vol. 55,4 (2011): 1548-65. doi:10.1016/j.neuroimage.2011.01.055
2. Oostenveld, R., Fries, P., Maris, E., Schoffelen, JM (2011). FieldTrip: Open Source Software for Advanced Analysis of MEG, EEG, and Invasive Electrophysiological Data. Computational Intelligence and Neuroscience, Volume 2011 (2011), Article ID 156869, doi:10.1155/2011/156869