Kinematics in the brain: The additional value of motor performance analysis during fMRI measurements

Objective To evaluate the additional value of adding movement kinematics into the design matrix in order to gain fine-grained insight in motor control strategies. Methods Ten healthy volunteers (age 41.8 ± 14.5, 5 males) performed a continuous elbow flexion/extension within a 1.5 MRI system. Movement kinematics were registered with the Zebris, a MRI compatible 3D motion capture system. Results Without taking the movement kinematics into consideration we found the expected systematic activation of the primary sensorimotor network, thought to generate movement execution [1] . By adding the kinematics to the fMRI design matrix we unmasked the involvement of fronto-cerebellar circuits and of the sensory cortex, as a function of both the irregularity and the frequency of movement, highlighting underlying processes of error-control to ensure optimal execution [2] . Discussion Our results reveal the modular and hierarchical structure of rhythmic motor control within brain networks: rhythmical movement generation relies on the activation of the primary sensorimotor network and error control of that movement results from the trade-off between automatically driven intermittent control involving cerebellar-frontal loops and continuous feedback involving the sensory cortex. Motor planning and error-control are important process involved in recovery post-stroke, and the detailed kinematic analysis during fMRI measurements seems to have an additional value possibly contributing to further understanding motor learning post-stroke.