Shared population-level dynamics in monkey premotor cortex during solo action, joint action and action observation

Studies of neural population dynamics of cell activity from monkey motor areas during reaching show that it mostly represents the generation and timing of motor behavior. We compared neural dynamics in dorsal pre motor cortex (PMd) during the performance of a visuomotor task executed individually or cooperatively and during an observation task. In the visuomotor conditions, monkeys applied isometric forces on a joystick to guide a visual cursor in different directions, either alone or jointly with a conspecific. In the observation condition, they observed the cursor's motion guided by the partner. We found that in PMd neural dynamics were widely shared across action execution and observation, with cursor motion directions more accurately discriminated than task types. This suggests that PMd encodes spatial aspects irrespective of specific behavioral demands. Furthermore, our results suggest that largest components of premotor population dynamics, which have previously been suggested to reflect a transformation from planning to movement execution, may rather reflect higher cognitive motor processes, such as the covert representation of actions and goals shared across tasks that require movement and those that do not.

Automated summary

Studies on the neural population dynamics in monkey motor areas during reaching tasks reveal that the activity mainly represents the generation and timing of motor behavior. The research shows that PMd encodes spatial aspects regardless of specific behavioral demands, with neural dynamics shared across action execution and observation. This suggests that the largest components of premotor population dynamics may reflect higher cognitive motor processes.