Effect of movement rate on corticokinematic coherence.

AIMS OF THE STUDY: This study investigates the effect of movement rate on the coupling between cortical magnetoencephalographic (MEG) signals and the kinematics of repetitive active finger movements, i.e., the corticokinematic coherence (CKC).

MATERIAL AND

METHODS

CKC was evaluated in ten right-handed healthy adults performing repetitive flexion-extension of the right-hand fingers in three different movement rate conditions: slow (∼1 Hz, duration: 11 min), medium (∼2 Hz, duration: 5 min) and fast (∼3 Hz, duration: 3 min). Neuromagnetic signals were recorded with a whole-scalp-covering MEG (Elekta Oy) and index acceleration was monitored with a 3-axis accelerometer. Coherent sources were estimated on the time-course of the cross-correlogram using equivalent current dipole (ECD) modeling.

RESULTS

Significant coherence was found at movement frequency or its first harmonics in all subjects and movement conditions. ECDs clustered at the primary sensorimotor cortex contralateral to hand movements. Movement rate had no effect on the coherence levels and the location of coherent sources.

CONCLUSIONS

This study demonstrates that the movement rate does not affect coherence levels and CKC source location during active finger movements. This finding has direct implications for CKC functional mapping applications and studies investigating the pathophysiology of central nervous disorders affecting proprioceptive pathways.