Is free-will an illusion?

The data from your link (fig. 7) indicate a decoding success rate of 55-60%. Barely better than flipping a coin.

http://www.cell.com/neuron/abstract/S0896-6273(10)01082-2

Quote:

Internally Generated Preactivation of Single Neurons in Human Medial Frontal Cortex Predicts Volition
Itzhak Friedcorrespondenceemail, Roy Mukamel, Gabriel Kreiman

Highlights
Progressive changes in firing rates precede self-initiated movements
Medial frontal cortex units signal volition onset before subjects' awareness
Prediction level is high (90%) based on neuronal responses in single trials
Volition could arise from accumulation of ensemble activity crossing a threshold
Summary
Understanding how self-initiated behavior is encoded by neuronal circuits in the human brain remains elusive. We recorded the activity of 1019 neurons while twelve subjects performed self-initiated finger movement. We report progressive neuronal recruitment over ∼1500 ms before subjects report making the decision to move. We observed progressive increase or decrease in neuronal firing rate, particularly in the supplementary motor area (SMA), as the reported time of decision was approached. A population of 256 SMA neurons is sufficient to predict in single trials the impending decision to move with accuracy greater than 80% already 700 ms prior to subjects' awareness. [/size]Furthermore, we predict, with a precision of a few hundred ms, the actual time point of this voluntary decision to move. We implement a computational model whereby volition emerges once a change in internally generated firing rate of neuronal assemblies crosses a threshold.

...

impending decision to move with accuracy greater than 80% already 700 ms prior to subjects' awareness.

Necessary but insufficient causation
Further information: Necessary and sufficient conditions

Indeterminists do not have to deny that causes exist. Instead, they can maintain that the only causes that exist are of a type that do not constrain the future to a single course; for instance, they can maintain that only necessary and not sufficient causes exist. The necessary/sufficient distinction works as follows:

If x is a necessary cause of y; then the presence of y necessarily implies that x preceded it. The presence of x, however, does not imply that y will occur.

If x is a sufficient cause of y, then the presence of x necessarily implies the presence of y. (However, another cause z may alternatively cause y. Thus the presence of y does not imply the presence of x.)

As Daniel Dennett points out in Freedom Evolves, it is possible for everything to have a necessary cause, even while indeterminism holds and the future is open, because a necessary condition does not lead to a single inevitable effect. Thus "everything has a cause" is, in his opinion, not a clear statement of determinism. Still, a question might arise why this and not that effect occurred: as long as a cause (something in the past) determines the answer to the question "effect A or B" (or why A or B), determinism will hold. On this basis "everything has a cause" might still be understood as an expression of determinism.

Intrinsic indeterminism versus unpredictability

A distinction is generally made between indeterminism and the mere inability to measure the variables (limits of precision). This is especially the case for physical indeterminism (as proposed by various interpretations of quantum mechanics). Yet some philosophers have argued that indeterminism and unpredictability are synonymous.

Both determinism and indeterminism seem to rule out free will

The deeper philosophical issue of free will can be framed as a paradox. On one hand, we all feel like we have free will, a multitude of behavioral choices to select among. On the other hand, modern biology generally investigates humans as though the processes at work in them follow the same biological principles as those in wasps. How do we reconcile our feeling of free will with the idea that we might be mechanical components of a mechanical universe?

What about determinism? When we say that a person chooses among several possible behaviors is there really a choice or does it just seem like there is a choice? Do people just (through the action of their more complex brains) simply have better behaviors than wasps, while still being totally mechanical in executing those behaviors? Dennett gives his definition of determinism on page one: All physical events are caused or determined by the sum total of all previous events. This definition dodges a question that many people feel should not be dodged: if we repeatedly replayed the universe from the same point in time would it always reach the same future? Since we have no way of performing this experiment, this question is a long-term classic in philosophy and physicists have tried to interpret the results of other experiments in various ways in order to figure out the answer to this question. Modern day physics-oriented philosophers have sometimes tried to answer the question of free will using the many-worlds interpretation, according to which every time there is quantum indeterminacy each possibility occurs and new universes branch off. Since the 1920s, physicists have been trying to convince themselves that quantum indeterminacy can in some way explain free will. Dennett suggests that this idea is silly. How, he asks, can random resolutions of quantum-level events provide people with any control over their behavior?

Indeterminism is not a solution to the free will problem

Since Dennett wrote Elbow Room (1984) there has been an ongoing attempt by some scientists to answer this question by suggesting that the brain is a device for controlling quantum indeterminacy so as to construct behavioral choice. Dennett argues that such efforts to salvage free will by finding a way out of the prison of determinism are wasted.

Yes, I do understand that there are views that there are practical and moral implications. I do see your view of testability/falsifiability differently. If behavior was not susceptible to the environmental influences of its consequences, and if prediction, verification, and replication (control) could not be achieved, then I think there would be no evidence for the environmental determinants of behavior. I think there are sound, logical reasons for making arguments relative to the extent to which what has been empirically demonstrated can be generalized, but those arguments, in my opinion, seem more reasoned than are ones that dismiss the evidence entirely.

It's before awareness, therefore it's not conscious. Doesn't matter if it's 1 second or 0.00000001 second.

Dennett suggests that this idea is silly. How, he asks, can random resolutions of quantum-level events provide people with any control over their behavior?

Rhetoric aside, anything "better than flipping a coin" is significant, considering the paucity of experimental evidence brought to bear for the free will side.

Understanding how self-initiated behavior is encoded by neuronal circuits in the human brain remains elusive.

We report progressive neuronal recruitment over ∼1500 ms before subjects report making the decision to move...

This increase of firing rate commences about 700 ms before [the report of the decision], that is, well before the subject becomes aware of the decision/urge to move. In this example, the rise continues beyond the [time of the report] and past the key press, before it declines and returns to baseline.

Although the nature of voluntary action is a centuries-old question, the study of its neuronal basis is exceedingly difficult as it involves a phenomenon intrinsic to an organism and invisible to an observer. The neuronal circuits and mechanisms underlying self-initiated behavior are poorly understood.

I grant for cheap this is a metaphysical assumption, after all any formal system starts up with some sort of assumption/s that cannot be proved. But believing there is Reason in the world its also an assumption that WE ALL do every time we feel the need to get up out of bed in the morning.

Reason is an illusion is itself an attempt at reasoning something.

No it isn't. It's a flat, presupposed assertion, no more, no less. It's the "starting point" of my metaphysical conception of the universe.