title: Local field potentials in primate motor cortex encode grasp kinetic parameters.
abstract: Reach and grasp kinematics are known to be encoded in the spiking activity of neuronal ensembles and in local field potentials (LFPs) recorded from primate motor cortex during movement planning and execution. However, little is known, especially in LFPs, about the encoding of kinetic parameters, such as forces exerted on the object during the same actions. We implanted two monkeys with microelectrode arrays in the motor cortical areas MI and PMd to investigate encoding of grasp-related parameters in motor cortical LFPs during planning and execution of reach-and-grasp movements. We identified three components of the LFP that modulated during grasps corresponding to low (0.3-7Hz), intermediate (~10-~40Hz) and high (~80-250Hz) frequency bands. We show that all three components can be used to classify not only grip types but also object loads during planning and execution of a grasping movement. In addition, we demonstrate that all three components recorded during planning or execution can be used to continuously decode finger pressure forces and hand position related to the grasping movement. Low and high frequency components provide similar classification and decoding accuracies, which were substantially higher than those obtained from the intermediate frequency component. Our results demonstrate that intended reach and grasp kinetic parameters are encoded in multiple LFP bands during both movement planning and execution. These findings also suggest that the LFP is a reliable signal for the control of parameters related to object load and applied pressure forces in brain-machine interfaces.
authors: Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany; Department of Bioengineering, Imperial College London, London, UK; Department of Electrical and Electronic Engineering, Imperial College London, London, UK. Electronic address: tomislav.milekovic@epfl.ch.
authors: Tomislav
authors: T
authors: Milekovic
authors: Department of Neuroscience and Institute for Brain Science, Brown University, Providence, RI 02912, USA; Center for Neurorestoration and Neurotechnology, U.S. Department of Veterans Affairs, Providence, RI 02912, USA. Electronic address: wilson_truccolo@brown.edu.
authors: Wilson
authors: W
authors: Truccolo
authors: Institute of Neuroscience and Medicine (INM-6), Research Center Jülich, Jülich, Germany; Institute of for Advanced Simulation (IAS-6), Research Center Jülich, Jülich, Germany; Theoretical Systems Neurobiology, RWTH Aachen University, Aachen, Germany; Riken Brain Science Institute, Wako-Shi, Japan. Electronic address: s.gruen@fz-juelich.de.
authors: Sonja
authors: S
authors: Grün
authors: Institut de Neurosciences de la Timone, CNRS-AMU, Marseille, France; Institute of Neuroscience and Medicine (INM-6), Research Center Jülich, Jülich, Germany; Riken Brain Science Institute, Wako-Shi, Japan. Electronic address: alexa.riehle@univ-amu.fr.
authors: Alexa
authors: A
authors: Riehle
authors: Institut de Neurosciences de la Timone, CNRS-AMU, Marseille, France. Electronic address: thomas.brochier@univ-amu.fr.
authors: Thomas
authors: T
authors: Brochier
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D058256:Brain Waves; D005260:Female; D018737:Hand Strength; D008251:Macaca; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement
keywords: Grasping; Kinetics; Local field potentials; Macaque; Motor cortex; Movement planning