Encephalon 57 on Mind Hacks has a link to a video interview of Rodolfo Llinas (video). There are many interesting ideas in this hour long discussion. The part I am quoting from the transcript is Llinas self-experimentation on the subject of free-will.
I understand that free will does not exist; I understand that it is the only rational way to relate to each other, this is to assume that it does, although we deeply know that it doesnt. Now the question you may ask me is how do you know? And the answer is, well, I did an actually lovely experiment on myself. I was extraordinary really. There is an instrument used in neurology called a magnetic stimulator its an instrument that has a coil that you put next to the top of the head and you pass a current such that a big magnetic field is generated that activates the brain directly, without necessary to open the thing. So if you get one of these coils and you put it on top of the head, you can generate a movement. You put it in the back, you see a light, so you can stimulate different parts of the brain and have a feeling of what happens when you activate the brain directly without, in quotes, you doing it. This of course is a strange way of talking but thats how we talk. So I decide to put it on the top of the head where I consider to be the motor cortex and stimulate it and find a good spot where my foot on the right side would move inwards. It was *pop* no problem. And we did it several time and I tell my colleague, I know anatomy, I know physiology, I can tell you Im cheating. Put the stimulus and then I move, I feel it, Im moving it. And he said well, you know, theres no way to really know. I said, Ill tell you how I know. I feel it, but stimulate and Ill move the foot outwards. I am now going to do that, so I stimulate and the foot moves inwards again. So I said but I changed my mind. Do it again. So I do it half a dozen times (it always moved inward) So I said, oh my god, I cant tell the difference between the activity from the outside and what I consider to be a voluntary movement. If I know that it is going to happen, then I think I did it, because I now understand this free will stuff and this volition stuff. Volition is whats happening somewhere else in the brain, I know about and therefore I decide that I did it In other words, free will is knowing what you are going to do. Thats all.