EEG functional connectivity metrics wPLI and wSMI account for distinct types of brain functional interactions.
Scientific Reports June 20, 2019 Laura Sophie Imperatori, Monica Betta, Luca Cecchetti et al.
Two methods for measuring brain connectivity, wPLI and wSMI, detect different types of neural interactions. Using simulated EEG data, wPLI is sensitive to couplings that mix linear and nonlinear dependencies, while only wSMI detects purely nonlinear interactions. In real EEG recordings from 12 healthy adults during wakefulness and deep sleep, both methods showed different sensitivity to changes in brain connectivity across these states. The findings suggest that using both methods together provides a more complete picture of the functional basis of consciousness in both healthy and altered states.