title: Corticokinematic coherence mainly reflects movement-induced proprioceptive feedback.
abstract: Corticokinematic coherence (CKC) reflects coupling between magnetoencephalographic (MEG) signals and hand kinematics, mainly occurring at hand movement frequency (F0) and its first harmonic (F1). Since CKC can be obtained for both active and passive movements, it has been suggested to mainly reflect proprioceptive feedback to the primary sensorimotor (SM1) cortex. However, the directionality of the brain-kinematics coupling has not been previously assessed and was thus quantified in the present study by means of renormalized partial directed coherence (rPDC). MEG data were obtained from 15 subjects who performed right index-finger movements and whose finger was, in another session, passively moved, with or without tactile input. Four additional subjects underwent the same task with slowly varying movement pace, spanning the 1-5 Hz frequency range. The coupling between SM1 activity recorded with MEG and finger kinematics was assessed with coherence and rPDC. In all conditions, the afferent rPDC spectrum, which resembled the coherence spectrum, displayed higher values than the efferent rPDC spectrum. The afferent rPDC was 37% higher when tactile input was present, and it was at highest at F1 of the passive conditions; the efferent rPDC level did not differ between conditions. The apparent latency for the afferent input, estimated within the framework of the rPDC analysis, was 50-100 ms. The higher directional coupling between hand kinematics and SM1 activity in afferent than efferent direction strongly supports the view that CKC mainly reflects movement-related somatosensory proprioceptive afferent input to the contralateral SM1 cortex.
authors.affiliation: Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, PO BOX 15100, FI-00076-AALTO Espoo, Finland. Electronic address: mathieu.bourguignon@aalto.fi.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bourguignon
authors.affiliation: Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, PO BOX 15100, FI-00076-AALTO Espoo, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Piitulainen
authors.affiliation: Laboratoire de Cartographie Fonctionnelle du Cerveau, UNI - ULB Neuroscience Institute, 808 Lennik Street, B-1070 Bruxelles, Belgium.
authors.forename: Xavier
authors.initials: X
authors.lastname: De Tiège
authors.affiliation: Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, PO BOX 15100, FI-00076-AALTO Espoo, Finland.
authors.forename: Veikko
authors.initials: V
authors.lastname: Jousmäki
authors.affiliation: Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, PO BOX 15100, FI-00076-AALTO Espoo, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Hari
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory; D025461:Feedback, Physiological; D005260:Female; D005385:Fingers; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009068:Movement; D011434:Proprioception / Q000502:physiology*; D066191:Sensorimotor Cortex / Q000502:physiology*; D055815:Young Adult
keywords: Human brain; Kinematics; Magnetoencephalography; Movement; Partial directed coherence; Proprioception; Sensorimotor cortex