coherence analysis
A signal processing technique measuring the linear correlation between EEG signals at different electrode sites as a function of frequency.
Full Definition
Coherence analysis is an advanced EEG analysis method that quantifies the degree of linear relationship between signals recorded from different brain regions across various frequency bands. Coherence values range from 0 (no correlation) to 1 (perfect correlation) and are calculated for each frequency bin in the spectrum. High coherence suggests functional connectivity between brain regions, while low coherence may indicate disconnection or independent processing. This technique is used in research to study brain networks, in clinical practice to identify epileptogenic zones, and in neurofeedback applications. Coherence can be affected by volume conduction, reference electrode choice, and skull thickness.
Usage
Usage note: Specify frequency bands and electrode pairs when reporting coherence findings.
In Context
- "Coherence analysis revealed decreased interhemispheric connectivity in the alpha band following the stroke." — Quantitative EEG report