Figure 1.
The graph shows the EEG power time course for each frequency band: alpha band (8–13 Hz) in green, lower beta (13–18 Hz) in red, and upper beta (18–25 Hz) in cyan. Each epoch (fix, still, movement and post movement) is labeled by a different color. Significant differences between adjacent time bins are indicated by asterisks whose color-code corresponds to that used for different bands. At the top of the figure a film strip shows an example illustrating the different epochs of the observed video clips.
Figure 2.
Time course of alpha-band power for target and non-target movements.
The graph shows the alpha-band EEG power time course for target (blue line) and non-target (red line) observed movements. Asterisks indicate significant differences between the corresponding bins in the two curves. Each epoch is labeled by a different color.
Figure 3.
Time course of upper beta rhythm for cyclic and no-cyclic movements.
The graph shows the EEG power time course for cyclic (blue line) and non-cyclic (red line) observed movements. Asterisks indicate significant differences between the corresponding bins in the two curves. Each epoch is labeled by a different color.
Figure 4.
Velocity profile and beta rhythm time course for each single type of movement.
The figure includes four panels (A, B, C, and D), one for each observed movements, showing the velocity profiles of observed hand (red line) superimposed on the EEG beta power (blue line). The velocity profiles were computed as the displacement of the fingertip of the actor between subsequent video frames. To make their values comparable, velocity data were normalized to their maximal value.
Figure 5.
Cross-correlation between the observed velocity and upper beta power.
In the figure the mean correlation value and its standard deviation are shown for each considered time lag (only positive values were considered) for both cyclic (panel A, green bars) and non-cyclic (panel B, blue bars) movements. Red asterisks indicate time shifts reaching a significant correlation (p<0.05, Bonferroni corrected).
Figure 6.
Presented stimuli and timeline of the experiment.
In the figure the structure of the administered trial is shown. The upper part shows still frames from the video clips displaying the four different observed movements. Target and cyclic attributes of movements are showed in the rightmost part of the upper panel. In the first line of the lower part, the four epochs of each trial are indicated. The second and third lines show the time bins considered in the analysis and the corresponding time interval (each 200 ms long), respectively.
Figure 7.
Top view of the scalp where the blue circles indicate electrodes located in the frontal clusters, red ones in parietal clusters. Green area includes left hemisphere electrodes, purple area the right hemisphere ones. The clusters includes C3, C4, P3, P4. In the figure electrodes belonging to occipital clusters (including O1 and O2) are not visible.