Figure 5.

Dominant channels of communication and reorganization in cortico-muscular network interactions across physiological states. Group-averaged matrices of coupling strength (measured as %TDS; see Materials and Methods 2.3) for (A) brain vs. chin muscle tone and (B) brain vs. leg muscle tone interactions coarse-grained as shown in Figure 4 to represent the average coupling of (i) each brain rhythm at a given cortical location with integrated spectral power of all EMG frequency bands (left panels in A,B), and (ii) each individual EMG frequency band with integrated spectral power of all cortical rhythms for different brain locations (right panels in A,B). Both brain-chin and brain-leg networks exhibit pronounced reorganization with transition across sleep stages—strong coupling during wake, intermediate during REM and light sleep, and weak coupling during deep sleep—consistently present for both types of coarse-grained matrices (left vs. right panels in A,B). Notably, for each sleep stage, high frequency cortical rhythms exhibit stronger TDS coupling across all cortical areas (EEG channels), playing role as dominant channels and main mediators in both brain-to-chin and brain-to-leg networks interactions (marked by warm colors in left panels in A,B).