For you to genuinely choose that you must have the idea to raise your hand before your brain is i nthe state that says "i think i will raise my hand" which means "you" require some higher/spiritual part of you to decide that and then put your brain i n that state (so also need power to move and manipulate matter).
You are your brain, the chemicals, the synapses the electrical charge. There is no separation, you are one and the same.