When we watch someone perform an action, understanding what they are doing is straightforward: muscles contract and limbs move. When we merely imagine performing an action, however, the brain enters a specific motor state that does not result in visible movement or muscle activity. Decoding this “hidden” motor activity directly from the brain has long been a challenge.

A new study led by Guido Barchiesi and carried out by Francesca Genovese and Elena Mussini from the University of Milan has introduced an innovative method, known as MultiMEP, that makes this possible. The technique allows information related to imagined actions to be transferred from the brain to the muscles, where it can be more easily extracted and accurately decoded.

Published in the international journal Brain Stimulation, the research was conducted at the Cognition in Action Lab (PhiLAB) at the University of Milan, directed by Corrado Sinigaglia, in collaboration with IMT School for Advanced Studies Lucca, the San Giovanni di Dio Fatebenefratelli Center in Brescia, the University of Brescia and the University of Trento.

To identify what participants were imagining, researchers used transcranial magnetic stimulation (TMS) to “push” motor information from the brain to the muscles. According to the team, the method opens up new possibilities for studying hidden motor states such as imagination, movement preparation and inhibition. The ability to infer these invisible states with high accuracy could lead to advances in diagnosis, rehabilitation and the development of brain–computer interfaces.