How equivalent are the action execution, imagery, and observation of intransitive movements? Revisiting the concept of somatotopy during action simulation

► We examined somatotopic activation during action execution, imagery, and observation. ► Somatotopy found in contralateral PMC and M1 during imagery and execution. ► No clear somatotopic organization during action observation in contralateral PMC and M1. ► Principle of functional equivalence holds more for imagery than for observation.