Neural Geometry from Mixed Sensorimotor Selectivity for Predictive Sensorimotor Control

Although recent studies suggest that activity in the motor cortex, in addition to generating motor outputs, receives substantial information regarding sensory inputs, it is unclear how sensory inflows affect the motor commands. Here, we recorded population neural activity in the motor cortex via microelectrode arrays while monkeys performed flexible manual interceptions of moving targets. During this task, which requires predictive sensorimotor control, the activity of most neurons in the motor cortex encoding upcoming movements, was influenced by ongoing target motion. An orbital geometry emerged in a latent neural state space at movement onset, suggesting that target speed modulates pre-movement activity in an orthogonal manner. This neural geometry was further evaluated with a representational model and a recurrent neural network (RNN) with task-specific input-output mapping. We propose that sensorimotor dynamics can be derived from neuronal mixed sensorimotor selectivity and dynamic interaction between modulations.