Fig. 4.

Spatial overlap/segregation of movement class-related gamma band activity patterns. a Spatial overlap/segregation (see Methods) of orofacial movement-related gamma band activity patterns within mouth motor cortex on a single-participant level; P1−P6 from top left to bottom right. Circles represent electrode contacts with mouth motor function within the borders of the ESM-defined mouth sensorimotor cortex (solid magenta outline). Each segment of a circle represents a specific orofacial movement class; leftward segment: lip licking, upper segment: speech production, rightward segment: laughing and lower segment: smiling. The greyscale of the segments indicates the significance with respect to movement-related gamma band activity at the respective electrode contact. Segments corresponding to movement classes with more than 30 trials from a participant are marked by green frames. b Position of the 8 × 8 electrode arrays of all six participants visualized on a standard brain surface. Orofacial movement classes are abbreviated as following: lip-licking (LL), speech production (SP), laughing (L) and smiling (S). Solid purple and pink lines indicate the course of the central and lateral sulcus, respectively. c Average pairwise segregation and overlap values and their standard deviation for all possible pairs of orofacial movement classes. In black: mean over participants and all orofacial movement classes; in dark green: mean over participants only for orofacial movement classes with >30 trials. d Movement-class-related functional overlap is shown as number of electrodes (y-axis) where significant (sign test; p < 0.01) gamma band activity was recorded for 0–4 movement classes (x-axis). Overall, the spatial overlap of movement class-related gamma band activity was rather low. In black: all movement classes; in green: only for movement classes with >30 trials