title: Enhanced corticomuscular coherence by external stochastic noise.
abstract: Noise can have beneficial effects as shown by the stochastic resonance (SR) phenomenon which is characterized by performance improvement when an optimal noise is added. Modern attempts to improve human performance utilize this phenomenon. The purpose of the present study was to investigate whether performance improvement by addition of optimum noise (ON) is related to increased cortical motor spectral power (SP) and increased corticomuscular coherence. Eight subjects performed a visuomotor task requiring to compensate with the right index finger a static force (SF) generated by a manipulandum on which Gaussian noise was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a green bigger circle. Electroencephalogram from the contralateral motor area, electromyogram from active muscles and finger position were recorded. The performance was measured by the mean absolute deviation (MAD) of the white dot from the zero position. ON compared to the zero noise condition induced an improvement in motor accuracy together with an enhancement of cortical motor SP and corticomuscular coherence in beta-range. These data suggest that the improved sensorimotor performance via SR is consistent with an increase in the cortical motor SP and in the corticomuscular coherence.
authors.affiliation: Department of Neurology, University of Freiburg Freiburg, Germany.
authors.forename: Carlos
authors.initials: C
authors.lastname: Trenado
authors.affiliation: Department of Neurology, University of Freiburg Freiburg, Germany ; Facultad de Psicologia, Benemérita Universidad Autonoma de Puebla Puebla, Mexico.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Mendez-Balbuena
authors.affiliation: Instituto de Fisiologia, Benemérita Universidad Autonoma de Puebla Puebla, Mexico.
authors.forename: Elias
authors.initials: E
authors.lastname: Manjarrez
authors.affiliation: Department of Neurology, University of Freiburg Freiburg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Huethe
authors.affiliation: Institute for Medical Biometry and Medical Informatics, University of Freiburg Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schulte-Mönting
authors.affiliation: Department of Psychiatry, University of Freiburg Freiburg, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Feige
authors.affiliation: Institute of Neuroinformatics, University of Zürich, ETH Zürich Zurich, Switzerland.
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Hepp-Reymond
authors.affiliation: Department of Neurology, University of Freiburg Freiburg, Germany.
authors.forename: Rumyana
authors.initials: R
authors.lastname: Kristeva
keywords: corticomuscular coherence; finger; force; humans; motor; noise; stochastic resonance