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Table 1 Common measures of synchrony and directionality in neuronal communication

From: Lack of redundancy between electrophysiological measures of long-range neuronal communication

Category Acronym Metric Description References
Non-directed coupling, synchrony Coherence (magnitude) Magnitude of the complex cross-spectrum [1, 2]
ImC Imaginary part of coherence Discards the real component of the cross-spectrum [3]
PLI Phase Lag Index Disregards the magnitude of the cross-spectrum and averages the sign of phase differences [4]
wPLI Weighted phase lag index Phase lags are weighed by the magnitude of the imaginary component of the cross-spectrum [5]
PLV Phase-locking value Circular resultant vector length of the phase differences [6]
PPC Pairwise phase consistency Computed based on the distribution of phase differences [7]
Directed (lead/lag, LFP-based) Coherence phase angle Angle of the complex cross-spectrum [8, 9]
CC Cross-amplitude coupling, amplitude cross-correlation Instantaneous amplitudes of two filtered LFPs are cross-correlated and the lag at which the peak occurred is determined [10]
Directed (causal influence) GC Granger causality Quantifies if the past of one time series can predict the future of another time series using autoregressive modelling [11,12,13,14]
npGC Non-parametric Granger causality Granger causality based on spectral matrix factorization [15]
PDC Partial directed coherence Normalized metric based on GC that measures direct influence from one time series to another [16]
DTF Direct transfer function Adaptation to multiple input variables closely related to PDC [17, 18]
Directed (phase-locking of local activity) SPC, MRL Spike-phase coupling, Mean resultant vector length Circular concentration of the phase distribution at which spikes occurred [2, 19,20,21]
PAC, CFC, MI Phase amplitude coupling, cross-frequency coupling, modulation index Modulation of the amplitude of high-frequency oscillations in one area by the phase of low-frequency oscillations from another area [22,23,24]
Directed (lead lag, spike-based) Phase angle of MRL Mean phase at which spikes occurred [20]
Phase-shifted MRL Calculation of the MRL based on phases at shifted lags [2, 19]