Grant: Project Grant

A basketball player must make split second decisions on how to avoid her opponent as she drives for the net. Even if the opponent bumps into her, skilled players rapidly make adjustments to score the basket. This ability to move and interact in a complex world is a key aspect of voluntary control. The present proposal will apply mechanical disturbances (small bumps to the arm) and/or visual disturbances (shift a cursor representing hand position) and observe how monkeys generate motor corrections under a range of behavioural contexts. Critically, we will also record in primary motor cortex (M1), a key region involved in voluntary control, to understand how it supports rapid motor corrections. The first project will modify specific features of the environment (target shape or presence of obstacles) to observe how neural activity in M1 of monkeys and corresponding motor corrections change based on these features of the environment. Preliminary observations highlight how M1 responses to a visual disturbance increase when the monkey must generate a more vigorous correction to attain a small target as compared to a large target. Our second project addresses the fact that we can use different types of feedback (visual or proprioceptive feedback of the limb) to make motor corrections. The question is how do you combine these different types of feedback. We use mathematical models that consider features of sensory feedback (noise and transmission times) to predict how each sensory signal should contribute to online control. Preliminary data highlight how feedback from the limb has a much more powerful influence on motor corrections than vision. Examination of the pattern in M1 of activity associated with different types of sensory feedback highlight that these sources of sensory feedback are broadly distributed across this motor region. The results will provide important properties on brain circuits control that support our ability to move and interact in the world.