title: Corticomuscular coherence reflects interindividual differences in the state of the corticomuscular network during low-level static and dynamic forces.
abstract: In the investigation of corticomuscular coherence (CMC), it remained unclear why some subjects do not present significant CMC. We predicted that such subjects will develop CMC as a result of learning as indexed by improved performance during a visuomotor task. We investigated CMC, cortical motor spectral power (SP), and performance in 14 subjects during isometric compensation of a static force or dynamic force (DF) with their right index finger. We compared data from the beginning of the experiment (Time-Period 1) and after learning (Time-Period 2). Eight subjects (Group CMC++) presented CMC during Period 1 which increased during Period 2. Six subjects (Group CMC-+) presented CMC only during Period 2. Group CMC-+ was "more desynchronized" (lower SP, and stronger task-related desynchronization) than Group CMC++. The performance was better in Group CMC++ than in Group CMC-+. Learning was associated with higher SP, higher CMC, and better performance in both groups. However, in the more complicated DF condition, Group CMC++ learned better than Group CMC-+. The present study demonstrates the presence of CMC in all subjects tested and evidence that this is due to the fact that individuals may fall into 2 different groups in terms of oscillatory motor control: Group CMC-+ presents CMC only after learning.
authors.affiliation: Neurological Clinic, Institute of Psychology, University of Freiburg, 79106 Freiburg, Germany.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Mendez-Balbuena
authors.forename: Frank
authors.initials: F
authors.lastname: Huethe
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schulte-Mönting
authors.forename: Rainer
authors.initials: R
authors.lastname: Leonhart
authors.forename: Elias
authors.initials: E
authors.lastname: Manjarrez
authors.forename: Rumyana
authors.initials: R
authors.lastname: Kristeva
mesh_terms: D000293:Adolescent; D000328:Adult; D004525:Efferent Pathways / Q000502:physiology; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D009415:Nerve Net / Q000502:physiology*; D009483:Neuropsychological Tests; D015588:Observer Variation; D011237:Predictive Value of Tests; D011597:Psychomotor Performance / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult