Role of the dorsal funiculi in movement control.

We trained monkeys to perform visuomotor tracking tasks in which the target's position was unpredictable, or in which the target jumped from one side of the screen to the other ('ballistic'). Section of the right dorsal funiculus at C2 resulted in transient deficits in both tasks, with full recovery of function. Subsequent removal of postcentral cortex in the left hemisphere produced a more intense and stable deficit in performance. We conclude that proprioceptive data on limb position and movement must be able to reach motor command structures by pathways paralleling the dorsal column-medial lemniscus system.