The main conclusion that can be drawn from this is that there isn’t an absolute distinction between body and soul, in which the body is just a vessel or shell for the conscious, acting soul. All decision making is preceded by brain activity, even before you are conscious of the decision.
Consciousness plays several roles including learning. It makes it possible to learn from your actions. Even if the decision. Came before I was conscious of it, I still can learn the effects of that decision, and through consciousness affect the way I behave in the future.
I think it is a mistake to make the line between decision and consciousness too sharp. I choose to post on this site. I might not be aware that my mind is made up until shortly after the fact, but I still thought through whether I wanted to do it. My consciousness is present every step of the way.
You can only make the distinction absolute under certain conditions. You have to assume no prior consciousness or experience. Prior experience determines how I will approach future decisions. So maybe in an infant, who has never experienced anything, the distinction is clearer, but in an adult who has a lifetime of experience behind him, and consequently consciousness, it isn’t so clear.
Another implication of the experiment is subconsciousness. Most of what we do is done subconsciously. I touch my face, fidget, look around, etc. But I am only aware of it once I start thinking about it.