phaselockingvalue.h File Reference

Phase Locking Value (Lachaux, Rodriguez, Martinerie & Varela 1999) between every channel pair. More...

#include "../connectivity_global.h"
#include "abstractmetric.h"
#include "../connectivitysettings.h"
#include <QSharedPointer>
#include <QMutex>
#include <Eigen/Core>

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Classes
class	CONNECTIVITYLIB::PhaseLockingValue
	Phase Locking Value estimator (Lachaux et al. 1999); amplitude-independent phase coupling, sensitive to zero-lag. More...

Namespaces
namespace	CONNECTIVITYLIB
	Functional connectivity metrics (coherence, PLV, cross-correlation, etc.).

Detailed Description

Phase Locking Value (Lachaux, Rodriguez, Martinerie & Varela 1999) between every channel pair.

SPDX-License-Identifier: BSD-3-Clause Copyright (c) 2018-2026 MNE-CPP Authors

Author

Daniel Strohmeier danie.nosp@m.l.st.nosp@m.rohme.nosp@m.ier@.nosp@m.gmail.nosp@m..com; Lorenz Esch loren.nosp@m.z.es.nosp@m.ch@tu.nosp@m.-ilm.nosp@m.enau..nosp@m.de; Juan GPC jgarc.nosp@m.iapr.nosp@m.ieto@.nosp@m.mgh..nosp@m.harva.nosp@m.rd.e.nosp@m.du; Gabriel Motta gabri.nosp@m.elbe.nosp@m.nmott.nosp@m.a@gm.nosp@m.ail.c.nosp@m.om; Christoph Dinh chris.nosp@m.toph.nosp@m..dinh.nosp@m.@mne.nosp@m.-cpp..nosp@m.org

Since

0.1.0

Date

April 2018

The Phase Locking Value is the resultant length of the unit-modulus cross-spectrum sample distribution,

PLV_{xy}(f) = | E[ S_{xy}(f) / |S_{xy}(f)| ] |

with output in [0, 1]: 1 means the instantaneous phase difference phi_x(f) - phi_y(f) is constant across trials (perfect inter-trial phase locking at frequency f) and 0 means the phase differences are uniformly distributed on the unit circle. Lachaux et al. (Human Brain Mapping, 1999) introduced PLV to detect transient phase coupling between visual-cortex sites in single-trial intracranial recordings without the amplitude bias that affects coherence-based measures.

Unlike imaginary coherence and the PLI family, PLV does not project out the zero-lag component of the phase distribution: it is therefore sensitive to genuine instantaneous coupling but cannot distinguish it from common-reference / volume-conduction mixing. PLV is the right choice for source-space analyses (where volume conduction is largely absorbed into the inverse operator) and for paradigms in which zero-lag locking is a hypothesis of interest; in sensor-space EEG/MEG it should be reported alongside ImagCoherence or WeightedPhaseLagIndex.

Definition in file phaselockingvalue.h.