I predict this would not happen the way you anticipate, at least for some ways to cash out 'taking control of your motor cortex'. For example, when a neurosurgeon uses a probe to stimulate a part of the motor cortex responsible for moving the arm, and eir patient's arm moves, and the neurosurgeon asks the patient why ey moved eir arm, the patient often replies something like "I had an itch", "it was uncomfortable in that position", or "What, I'm not allowed to move my arm now without getting grilled on it?"
I find this curio...
Just because you aren't aware of it, doesn't mean it didn't happen : )