There are many questions onthe minds of neuroscientists in modern society, but none may be so prevalent,so interesting, and so decisive as the free will debate. There has been plentyof data on both sides of the debate, and scientists fighting to prove theirviewpoints to be more accurate. However, looking at the data presented inrecent years, it becomes harder and harder to prove the existence of free willand easier to view the world through a probabilistic determinism lens. Some ofthe main neuroscience proof behind this concept would be seen in Libet’s buttonexperiment, Gazzaniga’s split-brain experiments, and Lau’s TMS experiment.
Now, before diving into the arguments against free will,let the journey begin with what appears to be a simple question on the surface,but is vital to this entire debate: what is free will? Free will shall bedefined as the ability for a person to make a conscious choice in a situationwhere there is an equal ability to choose any of the option. In simple terms,if faced with the same choice again, a person with free will would be able tomake a different choice. In addition, the person must have conscious controlover their actions.
In neuroscience terms, that would mean that all planningneuroactivity would occur before all execution activity. If these constrainsare proven to be accurate, then one could say that free will is an accurateconcept that can be applied to the modern world. The last thing to discussbefore getting into the big arguments would be the fact that there will be nodiscussion of the philosophy behind whether or not humans have free will orsouls, as that would extend the paper into non-scientific waters. The goal isto keep the discussion entirely scientific and focused on the neuroscientificevidence presented towards this debate. First off would be one of the largest and most citedexamples against free will, which is Libet’s button experiment. In thisexperiment, Libet would set up test subjects in a room with a button and aclock. He would tell them that they are free to press the button whenever, andthat whenever they decide to press the button, they should do so immediatelywhile also taking not of the position of the hands on the clock.
While theywere performing this, Libet was recording the readiness potential in thesubjects at the same time. Upon conducting the experiment, Libet found that thehuman brain unconsciously made a decision before the subject was consciouslyaware of it. Therefore, it was possible for the experimenters to predict whenthe subject would hit the button before the subject would know when they weregoing to hit the button. This is a huge hit against the concept of free will.If a person’s brain is unconsciously making the decisions before the person isconsciously aware of said decisions being made, that would mean that the brainis in control, not the person. The person isn’t making the decision as to whento hit the button, the brain is deciding when to hit the button and eventually,the person is aware of this decision and is able to act on it. If people didhave free will, Libet would have seen the readiness potential firing at nearlythe exact same time as the decision was being made by the person. This wouldshow that the processes of the brain and the conscious decision were being madeat the exact same time, leading to the idea that we are consciously able tomake our own decisions.
However, the results obtained instead show that we areonly conscious of the decisions that our brain make for us. We do not make thedecisions, we simply attempt to consciously keep up with them as they occur.Thus, Libet strikes a big blow against free will.
Another person who struck a major blow against free willwas Michael Gazzaniga. In fact, he wrote an entire book on the subject of freewill, titled Who’s In Charge? In this book, Gazzaniga makes many verypersuasive points, but some of Gazzaniga’s most impressive work is seen withsplit brain patients. Split-brain patients are people who have had their corpuscallosum, the part of the brain that connect the left and the right hemispheretogether and allows them to communicate, surgically severed.
These patientsnormally needed such an operation in order to help combat severe seizures, butalso presented Gazzaniga with subjects for some of the most impressive freewill experiments to date. In this experiment, Gazzaniga would present a subjectwith two images, one presented to the left visual field and one presented tothe right visual field. For most examples, it is said that the left visualfield is a picture of a chicken and the right visual field is a picture of asnow storm.
Due to the general crossing of visual information, the left visualfield information goes to the right hemisphere of the brain while the rightvisual field information goes to the left hemisphere of the brain. This iswhere the experiment gets interesting. The right hemisphere of the brain has asection know as the Interpreter, which is responsible for allowing us todescribe why we acted the way we did. It basically attempts to logicallyexplain all of our brains decisions in a way that makes sense.
So, going backto the experiment, after a moment, the patient is told to use both hands toselect two different items that relate to the photo. Once more the informationcrosses over, so the left-hand grabs something related to the chicken, say achicken foot, while the right-hand grabs something related to the snow storm,say a shovel. When questioned about the chicken foot the patient has no issuesimply relating the item straight back to the chicken, but when questionedabout the shovel, the patient does not connect it to the snow storm, but rathercreates a more complex, yet logical reasoning for why they chose the shovel inrelation to the chicken.
The interpreter had no access to the information aboutthe snow storm on the right side so, as a result, had to explain the brain’sdecision not only to the world, but also to themselves, as it related to thechicken. This, once again, majorly pulls away from the concept of free will. Ifwe had free will, one would think that we wouldn’t be able to make choices forreasons that we don’t understand. In addition, if we had free will, one wouldthink that we wouldn’t be making up reasons for or choices, we would absolutelyknow what choices we made, we would know why we made them, and we would be ableto explain it in a way that makes sense. The interpreter brings into questionfree will, as why would we need a part of the brain to help explain our choicesif we had free will? If we had free will, we wouldn’t need to explain ourchoices to ourselves and others, we would know the choices we made without ashadow of a doubt and wouldn’t need a part of the brain to make upexplanations. This is once more proof that the brain is acting unconsciouslyand then attempting to give us this information later via consciousness.
Yetanother strike against free will. As we continue to rack up strikes against free will, thenext major argument against free will would be the transcranial magneticstimulation experiment done by Lau and company. In this experiment, Lau hadsubjects act spontaneously and would apply transcranial magnetic stimulation tothe supplemental motor area immediately after the action. During this process,the experimenters attempted to record the perceived onset of intention to actand the perceived onset of the action. The experiment’s results are a littletricky, so I shall begin by discussing the important concepts involved in thisexperiment. When looking at how results should look in terms of free will, onewould expect to see that all experience of the action, including intent and allneural activity, would be entirely before or during the spontaneous action.This would help prove that we have conscious control of our actions, due to allexperienced intention being before our actions.
They focused on thesupplemental motor area, as this part of the brain is vital for the control ofmotion, including intention of motion, which is the part that Lau and companywas most interested in. In proceeding through the experiment, the data foundshowed that transcranial magnetic stimulation applied after the spontaneousaction shifted the perceived onset of intention to act backwards in time andshifted the perceived onset of the actual action forward in time. This wouldmean that there is some neural process that occurs after the spontaneous actionthat is altering the perceived time of the intention to act and the action inorder to make the two moments feel more connected. Our brain has a post hocprocess that is attempting to make it seem as though the intention to act andthe action are much more closely related in time then they really are, and thestimulation halts that process and puts into light how large a gap is actuallypresent between the intention and action. This would also mean that there issome part of perceived intention occurs after the actual motion occurs, so thatpart couldn’t have any impact on the actual action. In other words, part of ourconscious experience of perceived onset is neural activity that occurs afterthe action, and therefore cannot possibly have causal effect on the action. Ifpart of intention occurs after execution, that would mean that we do not haveas much conscious control over our actions as we once thought, and is a hugeissue for those attempting to prove free will to be an accurate way of viewing theworld.
These three experiments are able to show the scientificand neurobiological issues with the concept of free will directly, but anotherproblem facing the world is if we don’t have free will, what would that meanfor the world at large? Some have said that people cannot handle the concept ofnot having free will, others have said that it would change society at large.However, as this is not attempting to get philosophical and sticking to thefacts, the judicial system views all people as having free will and punishmentsare as a result of free will. If free will is scientifically proven to befalse, then that would mean that our judicial system would have to be entirelyreevaluated. Another question that comes from the fall of free will would be whatto replace it with. There are a few different options that people haveconsidered. However, the view that is the most accurate representation of the world today would be a conceptknown as probabilistic determinism, which in basic terms is the idea that thereis no free will, but rather our lives are controlled by a sequence of cause andeffect that is constantly occurring not only to us, but to the world around us.These events shape our brain and as a result, also shape our behavior and decision-makingabilities.
However, the probabilistic side to it comes from the fact that thereis still some randomness in the universe, from the Heisenberg principle inphysics, where one can know the position or the velocity of a certain particleat any given time but not both, to Lorenz’ concept of chaos theory and thebutterfly effect, which generally states that a tiny change in initialparameters, such as a butterfly flapping it’s wings, can have massiveunpredictable results, such as a tornado somewhere far away from the butterfly.These concepts, as well as many more prove that pre-determinism, or the conceptthat all life ever was pre-destinies at the point of the big bang, is mostlikely an inaccurate concept. There is enough randomness in day to day life thatthis concept of pre-determinism cannot be correct.
Rather, the idea that we aresimply the neural results of a probabilistic universe seems to be more accurateto the scientific evidence presented to the world in modern experiments.