Figure 1.
The different steps of the comparative study.
hr-EEG: high-resolution EEG, MNE: Minimum norm estimate, wMNE: Weighted Minimum norm estimate, LORETA: Low resolution Brain Electromagnetic Tomography, sLORETA: Standardized Low resolution Brain Electromagnetic Tomography, sPLV: single-trial Phase Locking Value, PE: Phase Entropy, R2: linear correlation coefficient, MI: Mutual Information, ImC: Imaginary Coherence ROIs: Regions of Interest, LO: Left Occipital; RO: Right Occipital, LT: Left Temporal, RT: Right Temporal, LF: Left Frontal, RF: Right Frontal, LP: Left Parietal.
Figure 2.
EEG signals and its reconstructed sources.
A) The recorded evoked responses for a given subject, B) the corresponding reconstructed sources and C) an example of the sources in each of the ROIs. The window of analysis is illustrated in transparent blue rectangle.
Table 1.
A summary of the previously published functional imaging studies of picture naming used to define the ROIs.
Figure 3.
Connectivity graphs obtained by using the different inverse and connectivity methods for hr-EEG (Up) and classical EEG montage (Bottom).
Red and blue lines denote the functional connectivity as measured in the gamma (>30 Hz) and beta (14–30 Hz) frequency band respectively.
Figure 4.
Comparison between the 32, 64, 128 and hr-montage for different inverse and connectivity methods.
Asterisk above boxes indicates significant difference (p<0.05). LI: Localization Index.
Figure 5.
The mean and standard variations of the R (percentage of identified edges for within each ROI) values obtained for the different functional connectivity methods (computed over the 12 subjects).
Figure 6.
Typical example of the brain network identified using wMNE and sPLV in the picture recognition and naming task.
A: lateral view B: Top view C: frontal view.
Table 2.
Mean and standard deviations of LI values (over the 12 subjects) for the tested inverse and connectivity methods.