Abstract
This study seeks to establish a reference for monitoring sensori-motor rehabilitation from hand paresis. The reference task utilizes finger gaiting in the context of within hand prehensile object manipulation. A video guided the 26 healthy, right-handed volunteers through the three phases of the task: (1) fixation of a hand holding a cuboid, (2) observation of the sensori-motor manipulation, (3) imitation of that motor action. fMRI recorded the task; graph analysis of the acquisitions revealed the associated functional cerebral connectivity patterns. Inferred from four 60 ROI, weighted graphs, the functional connectivities are consistent with a motor plan for observation and manipulation in the left hemisphere and with a network in the right hemisphere involving the inferior frontal gyrus, the site of intentional control of imitation. The networks exhibit (1) rich clubs which include sensori-motor hand, dorsal attention, cingulo-opercular and dorsal attention communities for observation and motor execution in both hemispheres, and (2) diversity clubs, significant only for manipulation and observation of the left hand, which include the dorsal visual association cortex, suggesting enhanced visual perception required for guiding the movement-limited left fingers. Short pathway analyses are consistent with these findings, confirming preferential involvement of ventral premotor cortices in the mirror network.