Do humans have free will? Are choices free in the sense that each of us is the concious authour of our actions? Many studies have been conducted to measure the readiness potentials (RP’s) (negative deflections of electroencephalography signal which precede a voluntary movement) of a given neural mechanism (generally the supplementary motor cortex (SMA) and the premotor cortex, thogh these signals can be found in many other cortical areas) in order to determine the casual relationship, if it exists, between them and the volitional action itself. The most famous example of this kind of study was conducted by Benjamin Libet and colleagues, whom used EEG to show that, in fact, the RP for a given action precedes the subjective feeling of volition by approximately five hundred milliseconds. Thus researchers suggested that the RP represents the primary cortical location in which the decision to move is processed and carried out.
Obviously, this result has some fairly far reaching implications if it is to be taken at face value. Thus it has been met with a great degree of both healthy and capricious skepticism. Using an fMRI and multivariate analysis, researchers aimed to overcome many of the limitations present in Libet’s original experiment by both designing it differently and taking full advantage of the fMRI’s ability to detect hemodynamic changes across many brain regions. With this technique researchers were able to determine that “the specific outcome of free choices can be determined several seconds before” the the subjective experience of volition (Haynes, 2011).
In order to understand these findings properly one must understand what mechanisms are involved with the coding of intentions in the human and primate brain. These areas include, but perhaps are not limited to; the primary motor cortex (Schwartz, et al, 1986), the SMA and pre-SMA (Kornhuber, Deecke, 1965), (Tanji, 2001), (Tanji, et al, 2009), the dorsolateral prefrontal cortex (Quintana, Fuster, 1999), posterior parietal cortex (Snyder, et all, 1997), (Toni, Shah, Fink, 2002), and the frontopolar cortex (Groll-Knapp, et al, 1977). The parietal cortex has also been implicated as the location where concious action plans are generated (Sirigu, et al, 2009), and where the “predictive control of movements” initiates (Haggard, 2005). It is within these areas that the researchers measured the hemodynamics using an fMRI and subsequently the local field potentials, as there is some good evidence indicating predictive fMRI signals may reflect high frequency local field potentials (Handwerker, et al, 2010), (Augath, et al, 2001).
The independent variables of this study are the type of test given (fMRI), the decoding method used to determine predictions (searchlight), and the choices which the subjects were given (pick one of two buttons). The dependent variables are the hemodynamic changes in the brain as measured by the fMRI in each subject, and thus the frequency of the local field potentials, as well as the choices the subjects actually make between the two buttons.
The researchers replaced the rotating clock from the original Libet experiment with a randomized stream of letters that updated every five hundred milliseconds. The subjects were to report which letter was being shown on the screen the moment their concious decision of pressing either the right button, or the left button was made. Subjects were told to fixate their gaze upon the center of the screen where the letters were being shown and at any time (no time restraints for making the decision were given) to decide to press either button. The researchers used a multivariate decoder to predict how the subjects would decide based on the representation of their brain activity by the fMRI.
The researchers found that two brain regions gave partial predictions about when and which button the subjects would choose, even though the subjects didn’t themslevles know which button they would yet choose. The first area implicated in the prediction of the decision was the Broddmann area 10 (BA10) in which predictive information existed a full seven to ten seconds before the subject was even aware of their choice. This indicates that the “which” decision in the brain is processed before the “when” and may involve a much more extended network in the brain. The parietal cortex also contained predictive information seconds in advance. The prediction of “which” button the subjects would choose was gauged at an accuracy of around sixty percent. While this is statistically significant, it is worth nothing that this is ten percent above the chance threshold. Information about “when” the subject would actually perform the volitional action was in congruence with Libet’s study (perhaps a bit before). The “when” prediction was upwards of eighty percent accurate without individualizong the multivariate decoding method, while as stated, the “which” decision was at about sixty percent accurate without individualizing the decoding. If the methods for decoding were individualized to the particular subject in the fMRI the accuracy of the “which” decision could be brought up to around seventy five to eighty percent.
Once again, the implications, taken at face value, seem to be vast. We must note, however, the limitations of such a study. Given that an fMRI measures hemodynamic changes, one must note that because of the hemodynamic latency, researchers focused on slightly longer timespans. Brain changes that happen in the millisecond range are not easily detectable (perhaps not at all detectable) by an fMRI. They also do not address “real world” decisions which have a high motivation value and risk of consequences, nor do they involve complex reasoning. It would be very interesting to understand if decisions can be predicted in real time. Doing so would help us to better appreciate and understand how our brain both processes and makes decisions on our behalf, which we subsequently take credit for. Ultimately the researchers proved their predictions to be correct and subsequently took down another barricade between brain activity and “free choice”.
Now, for a plain English translation of what I am talking about…This is but a couple examples of the ever growing scientific literature on free will. These studies help illuminate the reality of the life in which we live. The VAST majority of what goes on in out brain is inaccessible to our conscious introspection. We cannot account for the true causes of our actions. We can only act and then confabulate reasons for doing as we did. This is proven in study after study.
For example, in one study researchers asked subjects to hold a beverage in their hands and communicate with another individual in a controlled environment. The subjects were then asked to rate that individual on likability and friendliness. Strangely one group of individuals rated the stranger as “cold,” “unfriendly,” and said that their overall impression was not good. The other group said that the individual was “warm,” “friendly,” and said that their overall impression was very good. When each group was asked why they rated the stranger the way they did, they each gave various confabulated reasons for their particular rating of the stranger. The kicker is that all of the reasoning given by BOTH groups was utter and complete nonsense. The stranger was the exact same person, engaging in a pre-scripted conversation, in the same room, at the same time of day, in very much the exact same way. The only difference was that one group was given a warm beverage to hold and one group was given a cold beverage. The group given the warm beverage consistently labeled the person friendly and the group given a cold beverage consistently labeled the person as unfriendly.
Though I don’t want to get into the exact neurophysiological explanation for this phenomenon, suffice it to say that it has to do with mirror neurons, a brain evolved to think in metaphors, and cross talk between various brain regions. The point I want you to take away from this is that while the subjects post hoc rationalized the reasons why they did what they did, NOT ONE subject actually had the slightest idea. This test has been replicated, time after time, in a variety of different fashions.
When you do just a small bit of introspection concerning free will, you can easily see right through the illusion. Invoking strange metaphysical claims or adopting a compatablist viewpoint, is either complete nonsense (the metaphysical, supernatural, God, Allah, “Ideas of God,” spirits, souls, etc..) or bait and switch (compatablism). You no more control the next thought that pops into your head (and thus the next action you undertake) than the fact that you were born into this world. The act of “willing” something into being is simply misguided, at best. There is absolutely NO SENSE that can be made of such a proposition. Who is doing the willing? You? Who are you? Surely you must say, “I am my brain.”. If that isn’t your answer, your answer probably isn’t much worth considering. So assuming that is your answer, as it very well should be, you must understand that your brain does most of its work outside your conscious control. Indeed, every thought you have, every epiphany you dream up, every “everything” that is you is due to a special wiring of neurons who communicate with each other at synapses and gap junctions using chemical neurotransmitters and voltage gated ion channels. How these neurons interact and produce action potentials IS YOU! There is no more YOU than this. There is no extra part of you that is somehow “non physical” that can “will” an event into action. It’s a simple law of physics that the non physical can’t produce the physical (and don’t ask me how something came from nothing without reading a physics book first. If you can’t coherently explain the concept of “nothingness” then you don’t get to ask the question as a “got-ya” comment. If your genuinely interested I would be grateful to explain). There is MUCH more to say, but it’s not like I’m getting paid for this and who knows who will actually read this so let me end this now after but one more example. If you were to trade places with Charles Manson atom for atom, you must admit, if you have any sense at all, that you would be Charles Manson. You would thus be a psychopath who would kill innocent people for the exact same reason that he would. There is no extra part of you that could “choose” to see the world in a different way. Your synapses would be his synapses. Your life experience would be his life experience. You would do exactly as he did, for the exact same reasons, and God himself couldn’t do a thing about it. You must then admit that you are simply lucky not to be born with the brain of a psychopath. It isn’t because you willed yourself not to be a psychopath or not to murder children, or not to rape and pillage and steal. You simply got lucky. You live in a reductionist, deterministic universe. (Even if you didn’t, which you do, indeterminism leaves no room for free will BY DEFINITION). No respectable authority on any subject would say that the world is indeterministic, thus you have free will. Not one single Quantum Physicist will tell you that. And if you happen to think that Quantum Mechanics somehow paves the way for free will, it doesn’t. Also with a proper understanding, quantum mechanics doesn’t eliminate classical determinism. I don’t have the time nor the desire to explain these more technical points fully. Perhaps if anyone reads this and then wants to explore these escape routes we can then discuss why it won’t work. Until then, Sianora and don’t think of the word COW! COW! COW! (Exercise your free will)!