Local field potentials allow accurate decoding of muscle activity 1 2 3

25 Local field potentials (LFPs) in primary motor cortex include significant information 26 about reach target location and upper limb movement kinematics. Some evidence suggests that 27 they may be a more robust, longer-lasting signal than action potentials (spikes). Here we assess 28 whether LFPs can also be used to decode upper limb muscle activity, a complex movement29 related signal. We record electromyograms (EMGs) from both proximal and distal upper limb 30 muscles from monkeys performing a variety of reach-to-grasp and isometric wrist force tasks. 31 We show that LFPs can be used to decode activity from both proximal and distal muscles with 32 performance rivaling that of spikes. Thus, motor cortical LFPs include information about more 33 aspects of movement than has been previously demonstrated. This provides further evidence 34 suggesting that LFPs could provide a highly-informative, long-lasting signal source for neural 35 prostheses. 36 37