Which statement best describes the role of the supplementary motor area?

• A. It deals with well-learned/implicit motor sequences that do not require extensive monitoring of the external environment.
• B. It primarily processes auditory information.
• C. It is the primary region for language production.
• D. It mediates conscious sensory awareness of touch.

Answer: (A)

The main idea here is that the supplementary motor area plans and initiates movements that are internally generated, especially well-practiced sequences, without needing continuous guidance from the external environment. This area supports the internal sequencing and timing of actions, including coordinating movements that you’ve learned to perform automatically, often before you actually move. It’s particularly active for internally guided, complex motor plans and for planning the next steps in a sequence that you can execute from memory, such as a familiar piano passage or a well-practiced tapping pattern.

This differs from areas that handle movements guided by external cues, as well as from regions dedicated to other functions. Processing auditory information happens mainly in auditory cortices of the temporal lobe. Language production is primarily associated with Broca’s area in the frontal lobe. Conscious sensory awareness of touch is handled by the somatosensory cortex in the parietal lobe. The supplementary motor area sits squarely in the motor planning network for internally generated, learned sequences, not in those other functions.