What is phase locking EEG?

This can be anything, even a particular signature in the EEG signal, such as the phase of a slower oscillation. For example, you could extract epochs of gamma-band filtered data locked to the phase of theta oscillation or amplitude of delta oscillations; then compute PLV time course relative to these.

What is PLV value?

denotes the expected value. The PLV takes values on [0, 1] with 0 reflecting the case where there is no phase synchrony and 1 where the relative phase between the two signals is identical in all trials. PLV can therefore be viewed as a measure of trial to trial variability in the relative phases of two signals.

What is the point of phase locking?

Phase-locking In the case of auditory neurons, this means firing an action potential at a certain phase of a stimulus sound being delivered. It has been seen that when being played a pure tone, auditory nerve fibers will fire at the same frequency as the tone.

What is the phase locking value?

Phase Locking Value (PLV) is a statistic that can be used to investigate task-induced changes in long range synchronization of neural activity. This method is introduced in Lachaux et al., (1999) Human Brain Mapping.

Why does phase locking occur?

the tendency for a neural action potential to occur at a certain phase of a pure-tone stimulus. More generally, phase locking refers to the ability of a neuron to synchronize or follow the temporal structure of a sound. In the auditory nerve, fibers can phase lock to frequencies below 4 to 5 kHz.

Why is phase locking important for hearing?

Phase locking underlies the ability to localize sounds based on interaural phase differences or interaural time differences (see. Its role in monaural hearing is uncertain, but it has been proposed as a mechanism for the coding of pitch.

What is auditory phase locking?

In the auditory system, phase locking refers to the fact that the probability of neuronal action potentials (spikes) varies as a function of the phase of low-frequency tones, low-frequency components of broadband sounds, or low-frequency fluctuations of the envelope (for review, see Joris et al., 2004; Heil and …

What is Hilbert transform and where we use it?

The Hilbert transform is a technique used to obtain the minimum-phase response from a spectral analysis. When performing a conventional FFT, any signal energy occurring after time t = 0 will produce a linear delay component in the phase of the FFT.

Why does phase locking happen?

Phase Locking is an empirical observation that supports the volley principle. When auditory nerve neurons fire action potentials, they tend to respond at times corresponding to a peak in the sound pressure waveform, i.e., when the basilar membrane moves up.

Why do we take Hilbert transform?

The Hilbert transform is useful in calculating instantaneous attributes of a time series, especially the amplitude and frequency. It is a simple and useful algorithm for instantaneous frequency extraction of a signal.

What are the applications of Hilbert transform?

In addition to the MathML phase shift that it introduces between the real and imaginary parts, the Hilbert transform can be used in the theory of modulation to determine the amplitude modulation, phase modulation and frequency modulation of a time-dependent signal MathML.

What is neural phase locking?

Phase locking refers to the tendency of a neuron to fire action potentials at particular phases of an ongoing periodic sound waveform, such as the sinusoidal waveforms that are typically used in physiological studies of the auditory system.

Can a phase locked EEG be discriminated?

Phase-locked (e.g. evoked potentials) and non-phase-locked EEG activities cannot be discriminated when both types of activity are within the same frequency band. This means an ERP can mask EEG desynchro- nization or synchronization.

How is the phase lag index used in EEG?

Phase Lag Index is a tool to estimate connectivity in EEG in a way that eliminates volume conduction effects. However, it is also likely to discard a significant component of genuine interactions.

Why do we disregard 0 phase difference in EEG?

The fundamental idea here is to disregard phase locking that is centered around 0 phase difference as a means of excluding volume conduction effects (at the risk of ignoring true instantaneous interactions). This also applies to phase locking at π, 2π and so on, i.e. repeating at every π , also given as

What is the purpose of phase locking value?

Phase Locking Value (PLV) is a statistic that can be used to investigate task-induced changes in long range synchronization of neural activity from EEG data.