As a spirit in a human body, what is the mind if it s not the power behind the brain?

The mind is what the brain thinks it is.

Or, "I think I think I am".

That's basically state of the art what modern neuroscience knows.

There was an interesting experiment once, they put people in a brain scanner (fMRT, to be exact), and asked them, to lift an arm whenever they choose, no matter which arm.

The brain had decided which arm to lift half a second before the arm was lifted. That can't be explained by muscular raction and transmission delay through neurons, the brain had decided, the moment the task was given, what to do, although the task was completely random. And it seems to be irreversible, once a decision is taken, you go for it.

That simple experiment, I think, gives us a deep insight into ourselves.

There is no spirit, really. Everything we are -- what we think, our emotions, everything that makes us human -- is the brain. Once all those electrical currents aren't running through there anymore, poof. we're gone. And honestly, the concept is a little terrifying.

WOW; That is deep, like a dream state where your dreams control the mind in a waking state.