Free Will & Neurology: brain activity to conscious decision

Your brain might not be just grey matter. Refer to plasma physics. Google: dapla.

What about free will over your own thoughts.
Say you are walking along the road and a thought just seems to pop into your head from nowhere.
I mean you don't go about thinking, what will I think about now, the thoughts are just there.
Say a van passes you in the street, you catch sight of the driver for a split second, and he reminds you of someone you knew 20 yrs ago. How can you NOT think about it. Then that thought will lead to another train of thought and so on. Are we in control here?

Yes, what would the experiment conclude if the subject had sat there without pressing any buttons at all?

SHFUTS-- Whether we do or don't have such "mental reflexes," what is of interest is that the inhibition of the motor act follows a conscious decision to inhibit the act. Whether the mechanism of inhibition involves subconscious processes or not, it does not occur randomly but following a decision to cancel the act. That said, as I stated in a comment above, unequivocal interpretations of these experiments are problematic. IMO science cannot (at present) settle the free will debate.

could we not just have mental reflexes to abort decisions? that could be dependant on subconciouse processes that are much faster

Yet you still can't do experiments without induction PERIOD.

Thus cause and effect are a proof, because without them you science doesn't exist with any basis or utility.

BTW, How do you know that all unconscious processes ("the subconscious") are deterministic? Given our knowledge of Quantum Mechanics, it is entirely conceivable that it is not quite so simple. Incidentally, Indeterminism would not in itself entail free will. Indeed, many argue that free will relies on deterministic processes inasmuch as goal-oriented acts require predictable sequences to be enacted.

Also, by pre-motor activity (above) I refer to the readiness potential.

The process of overriding was conscious. Subjects were asked to form the intention to push a button and then to quickly override the "choice." The pre-motor potential (RP) appeared, but the act was not carried out. Libet spoke of "veto powers."

No, the brain is not distinct from the person in my view. No dualism here. I only meant that after the pre-motor potential appeared in the brain, subjects were able to override the prompt.

But if the whole process of overriding a decision is made in the subconscious before we are consciously aware of it, it would not change anything. Given the subconscious being mechanical and deterministic, we would not be consciously aware of it since these are things in the subconscious.

Also you speak of the brain and the person as though they are two different things when you say "when the brain determines to push the button" when it's the brain that controls our consciousness, correct?