PreSMA

PreSMA, or pre-supplementary motor area, is a region of the medial frontal cortex located on the medial surface of the frontal lobe, rostral to the supplementary motor area (SMA) proper. It lies primarily in the superior frontal gyrus and adjacent medial structures and is considered part of the SMA complex but distinct from SMA proper.

Functionally, preSMA is linked to higher-level aspects of motor control and cognitive planning. It participates in action selection, preparation of voluntary movement, and sequencing, particularly when decisions are under conflict or governed by novel rules. It also contributes to response inhibition, task switching, and error monitoring, and it may contribute to learning and adapting motor plans.

Connectivity and networks: PreSMA maintains reciprocal connections with dorsolateral prefrontal and anterior cingulate cortices, posterior parietal areas, and subcortical circuits via the basal ganglia and thalamus, with cerebellar involvement in motor learning. These connections position it to integrate cognitive and motor information during action planning.

Research and clinical relevance: PreSMA is studied with functional imaging, such as fMRI, as well as techniques like transcranial magnetic stimulation and intracranial stimulation. Disruption of activity in this area can impair planning and inhibition of actions, highlighting its role in executive control and voluntary movement.