The pathways for action

Early nineteenth-century studies demonstrated, on the basis of clinical, experimental, and anatomical evidence, that a motor pathway, the corticospinal or pyramidal tract, passes from a specific area of the cortex, the precentral motor cortex, to the brainstem and spinal cord. The motor cortex can be seen as a topographic map of the movable body parts, and damage to the cortex or pathways produces correspondingly localized paralysis. However, there are a great many other pathways that link other areas of the cortex to parts of the brain active in the control of movements. These still play a puzzling role in the standard model where the control of movements focuses on cortical contributions to voluntary movements by the corticospinal pathways.