Propagating spatio-temporal activity patterns across macaque motor cortex carry kinematic information

Propagating spatio-temporal neural patterns are widely evident across
sensory, motor and association cortical areas. However, it remains unclear
whether any characteristics of neural propagation carry information about
specific behavioral details. Here, we provide the first evidence for a
link between the direction of cortical propagation and specific behavioral
features of an upcoming movement on a trial-by-trial basis. We recorded
local field potentials (LFPs) from multi-electrode arrays implanted in the
primary motor cortex of two rhesus macaque monkeys while they performed a
2-D reach task. Propagating patterns were extracted from the
information-rich high-gamma band (200–400Hz) envelopes in the LFP
amplitude. We found that the exact direction of propagating patterns
varied systematically according to initial movement direction, enabling
kinematic predictions. Furthermore, characteristics of these propagation
patterns provided additional predictive capability beyond the LFP
amplitude themselves, which suggests the value of including mesoscopic
spatio-temporal characteristics in refining brain-machine interfaces.