What are the cortical components of motor performance? Explain the difference between the roles of primary motor cortex and supplementary motor cortex.

What are the cortical components of motor performance? Explain the difference between the roles of primary motor cortex and supplementary motor cortex.

Three brain areas used in motor control and motor cognition are:
- primary motor cortex
- supplementary motor cortex
- premotor cortex


The primary motor cortex is a brain region that is located in the posterior portion of the frontal lobe.
- It works in association with other motor areas including premotor cortex, the supplementary motor area, posterior parietal cortex, and several subcortical brain regions, to plan and execute movements.
- It is a part of the cerebral cortex that is most directly involved in controlling the activity of motoneurons.
- An orderly representation of movements by body part exists within primary motor cortex. Each primary motor cortex controls the muscles on the opposite side of the body

The supplementary motor cortex (SMA) is a part of the primate cerebral cortex that contributes to the control of movement. It is located on the midline surface of the hemisphere just in front of the primary motor cortex.
- Neurons in the SMA project directly to the spinal cord and may play a role in the direct control of movement
- Possible functions attributed to the SMA include the postural stabilization of the body, the coordination of both sides of the body, the control of movements that are internally generated rather than triggered by sensory events, and the control of sequences of movements. All of these proposed functions remain hypotheses. The precise role of the SMA is not yet known and it may serve multiple roles.

..and the premotor cortex: It projects directly to the spinal cord and therefore plays a role in the control of planning movement.