Science of Free Will
A Scientist’s Defense of Free Will
Our commonsensical view holds that everything we do in life is a choice and we are totally free to choose between the options which we think are available to us. Many scientists, however, see a fundamental problem with the conventional wisdom about free will and claim that it is nothing more than an illusion.
After all, the adult brain is a 1.3-kg mass of jellylike tissue made up of billions of neurons. And all those neurons consist ultimately of atoms obeying the exact same laws of physics as everything else in the universe. Everything that happens- in a physical universe such as ours- must necessarily have an inevitable cause. This means that for any decision we make, we could not have done otherwise. So, we have no true choice. No free will.
Since the cause-effect relationship is the fundamental tenet of science, if you are in one fashion or another defending free will, then you are wasting your time and giving in to this anti-scientific nonsense, saying that here is something which has not been caused.
When talking about free will, the one thing that is almost invariably brought up by free will deniers is the famous Libet experiment.
Nearly three decades ago, a neuropsychologist by the name of Benjamin Libet at the University of California, performed one of the most thought-provoking and controversial experiments in neuroscience ever. Libet asked experimental subjects to perform a simple movement such as flicking the wrist or finger whenever they wanted to. Participants could watch and specify the position of a moving spot of light on a special clock when they made an arbitrary decision to move their wrists. Libet wanted to determine when participants became consciously aware of deciding to act prior to the actual movement by monitoring their cerebral activity using scalp electrodes. Libet's recordings revealed that the report of the conscious decision to act occurred about 350ms after the onset of an electrical signal in the motor cortex- the area in the brain triggering and preparing the muscle to move.
What this means is that consciousness comes on the scene too late for it to play any role in initiating action. This hammered final nail in the coffin of free will as it provided "the much anticipated empirical evidence" in support of the you-have-no-free-will argument. Libet himself has been somewhat careful in interpreting the implications of his experiments.
Many others, unfortunately, have certainly been certainly less modest.
In the following years, others researchers produced results similar to the original Libet experiment. With its ever increasing popularity unmatched by any other brain imaging technique, it would be virtually impossible to imagine a neuroscience experiment not armed with fMRI- functional magnetic resonance imaging. Indeed so, in a study published in Nature Neuroscience in 2008 by Chun Soon, participants were asked to push one of two buttons with their left or right index fingers anytime they wanted and Soon tried -using fMRI- to predict which hand a particular subject was going to use to press the button.
The brain activity that predicted which button would be pressed began 7 seconds before the subject was conscious of his decision. Although many of the limitations and intricacies of the technique were glossed over, most media outlets went bananas over the story, spreading it around the globe, either overselling or watering down the message.
The assumption behind all this empirical evidence against free will is that conscious decision takes place at an instant which can be compared with the neural activity corresponding to it. It is however very likely that- like many processes in our bodies- it is rather a smeared-out event, which can’t possibly occur instantaneously. It would be like asking when a baby starts talking: there is no clear-cut, dividing line between the baby’s silence and speech. It is a process, a continuum. For the experimental protocols that Libet and his followers used, relying heavily on awareness of actions and time estimation of accuracy, this is a crucially different definition.
Another fundamental aspect which is widely overlooked in these studies is that they provide no proof whatsoever that brain activity could happen without conscious decision taking place. This is a critical point particularly because neural activity precedes the conscious awareness of the decision corresponding to it. Understandably, it is not surprising that brain activity that takes place before the will has been historically thought as the source that leads to behavior. Anything preceding an effect must be a cause. Not the tiniest shred of evidence exists, however, in favor of the idea that brain activity can occur without the corresponding decision-making. This is an argument piercing the veil of the fashionable you-have-no-free-will dogma that we are being told with religious certainty and confidence.
A methodological flaw that strikes me as odd is that these experiments always involve a test subject fully aware of the choice they are going to make. Is it surprising than that our brain would prepare for this decision? In real life, as opposed to the simple, binary decisions of Libet, we are faced with many complex situations where we have not a clue of the options available to us beforehand. The volunteers in the experiment had no choice other than the timing of their actions. They could not decide among different action alternatives as the action itself was predetermined.
But more than that, in simple actions like flexing your wrist only procedural memory is involved, whereas in typical free will situations, requiring a deeper assessment of the current situation in tandem with memories of the past experiences in our cognitive toolkit, episodic memory plays a substantial role. So, it’s very much doubtful that the experiment is telling us something about free will. If anything, the Libet experiment is nothing more than a very crude oversimplification which is very difficult to justify in terms of everyday situations that we all encounter in real world. Instead, monitoring brain activity as we go around making more complex choices can be more interesting but this is no trivial task to accomplish.
Aside from all these methodological criticisms and flaws, there is one fundamental assumption at the core of the scientific framework in which all these experiments operate. The view that there is no free will because the brain is made of atoms and molecules that obey physical laws is a great example of reductio ad absurdum.
Let's take a water molecule- two parts hydrogen and one part oxygen- if you'll pardon the cliché. When combined, they produce a colorless, tasteless and odorless liquid. Can you take the hydrogen and the oxygen atom in isolation and predict that water will emerge from their combination? A possible reply from a physicist would be that once we acquire all the necessary knowledge of the underlying physics, we'll be able to explain all the seemingly emergent properties which at the moment we can’t explain.
But not every physicist buys this argument. Here's the rub: the Nobel prize winning condensed matter physicist Philip Anderson wrote a famous article entitled ‘More is Different’ in 1972 where he defended the view that the laws and principles he studied as a condensed matter physicist were emergent and there are plenty of phenomena exhibited by macroscopic systems whose existences cannot be predicted directly from an underlying, microscopic theory. In other words, the information obtained from the whole can’t be explained by the sum of information from each individual element. Simply put, just because matter in the universe- including all atomic constituents in the human body- obeys certain physical laws, it really doesn't follow that the choice itself must also be bound by the same laws. There is a huge gap here which is not explained by this line of reasoning. This is simply bad logic.
Thanks to the seeming there-is-no-free-will consensus among some mainstream scientists who have espoused their ideas loudly enough with a great air of confidence, many others-scientists and lay people alike- followed and accepted their line of thinking uncritically.
For people, free will matters. So it's very important that the science shaping our understanding of free will is accurate.
Before I, for one, give up my free will, I’d like to await more persuasive hard evidence and avoid forming premature conclusions. Is that too much to ask?
What Neuroscience Says about Free Will
We're convinced that it exists, but new research suggests it might be nothing more than a trick the brain plays on itself
It happens hundreds of times a day: We press snooze on the alarm clock, we pick a shirt out of the closet, we reach for a beer in the fridge. In each case, we conceive of ourselves as free agents, consciously guiding our bodies in purposeful ways. But what does science have to say about the true source of this experience?
In a classic paper published almost 20 years ago, the psychologists Dan Wegner and Thalia Wheatley made a revolutionary proposal: The experience of intentionally willing an action, they suggested, is often nothing more than a post hoc causal inference that our thoughts caused some behavior. The feeling itself, however, plays no causal role in producing that behavior. This could sometimes lead us to think we made a choice when we actually didn’t or think we made a different choice than we actually did.
But there’s a mystery here. Suppose, as Wegner and Wheatley propose, that we observe ourselves (unconsciously) perform some action, like picking out a box of cereal in the grocery store, and then only afterwards come to infer that we did this intentionally. If this is the true sequence of events, how could we be deceived into believing that we had intentionally made our choice before the consequences of this action were observed? This explanation for how we think of our agency would seem to require supernatural backwards causation, with our experience of conscious will being both a product and an apparent cause of behavior.
In a study just published in Psychological Science, Paul Bloom and I explore a radical—but non-magical—solution to this puzzle. Perhaps in the very moments that we experience a choice, our minds are rewriting history, fooling us into thinking that this choice—that was actually completed after its consequences were subconsciously perceived—was a choice that we had made all along.
Though the precise way in which the mind could do this is still not fully understood, similar phenomena have been documented elsewhere. For example, we see the apparent motion of a dot before seeing that dot reach its destination, and we feel phantom touches moving up our arm before feeling an actual touch further up our arm. “Postdictive” illusions of this sort are typically explained by noting that there’s a delay in the time it takes information out in the world to reach conscious awareness: Because it lags slightly behind reality, consciousness can “anticipate” future events that haven’t yet entered awareness, but have been encoded subconsciously, allowing for an illusion in which the experienced future alters the experienced past.
In one of our studies, participants were repeatedly presented with five white circles in random locations on a computer monitor and were asked to quickly choose one of the circles in their head before one lit up red. If a circle turned red so fast that they didn’t feel like they were able to complete their choice, participants could indicate that they ran out of time. Otherwise, they indicated whether they had chosen the red circle (before it turned red) or had chosen a different circle. We explored how likely people were to report a successful prediction among these instances in which they believed that they had time to make a choice.
Unbeknownst to participants, the circle that lit up red on each trial of the experiment was selected completely randomly by our computer script. Hence, if participants were truly completing their choices when they claimed to be completing them—before one of the circles turned red—they should have chosen the red circle on approximately 1 in 5 trials. Yet participants’ reported performance deviated unrealistically far from this 20% probability, exceeding 30% when a circle turned red especially quickly. This pattern of responding suggests that participants’ minds had sometimes swapped the order of events in conscious awareness, creating an illusion that a choice had preceded the color change when, in fact, it was biased by it.
Importantly, participants’ reported choice of the red circle dropped down near 20% when the delay for a circle to turn red was long enough that the subconscious mind could no longer play this trick in consciousness and get wind of the color change before a conscious choice was completed. This result ensured that participants weren’t simply trying to deceive us (or themselves) about their prediction abilities or just liked reporting that they were correct.
In fact, the people who showed our time-dependent illusion were often completely unaware of their above-chance performance when asked about it in debriefing after the experiment was over. Moreover, in a related experiment, we found that the bias to choose correctly was not driven by confusion or uncertainty about what was chosen: Even when participants were highly confident in their choice, they showed a tendency to “choose” correctly at an impossibly high rate.
Taken together, these findings suggest that we may be systematically misled about how we make choices, even when we have strong intuitions to the contrary. Why, though, would our minds fool us in such a seemingly silly way in the first place? Wouldn’t this illusion wreak havoc on our mental lives and behavior?
Maybe not. Perhaps the illusion can simply be explained by appeal to limits in the brain’s perceptual processing, which only messes up at the very short time scales measured in our (or similar) experiments and which are unlikely to affect us in the real world.
A more speculative possibility is that our minds are designed to distort our perception of choice and that this distortion is an important feature (not simply a bug) of our cognitive machinery. For example, if the experience of choice is a kind of causal inference, as Wegner and Wheatley suggest, then swapping the order of choice and action in conscious awareness may aid in the understanding that we are physical beings who can produce effects out in the world. More broadly, this illusion may be central to developing a belief in free will and, in turn, motivating punishment.
Yet, whether or not there are advantages to believing we’re more in control of our lives than we actually are, it’s clear that the illusion can go too far. While a quarter-of-a-second distortion in time experience may be no big deal, distortions at longer delays—which might plague people with mental illnesses like schizophrenia and bipolar disorder—could substantially and harmfully warp people’s fundamental views about the world. People with such illnesses may begin to believe that they can control the weather or that they have an uncanny ability to predict other people’s behavior. In extreme cases, they may even conclude that they have god-like powers.
It remains to be seen just how much the postdictive illusion of choice that we observe in our experiments connects to these weightier aspects of daily life and mental illness. The illusion may only apply to a small set of our choices that are made quickly and without too much thought. Or it may be pervasive and ubiquitous—governing all aspects of our behavior, from our most minute to our most important decisions. Most likely, the truth lies somewhere in between these extremes. Whatever the case may be, our studies add to a growing body of work suggesting that even our most seemingly ironclad beliefs about our own agency and conscious experience can be dead wrong.
Is Free Will an Illusion?
Don't trust your instincts about free will or consciousness, experimental philosophers say
IT SEEMS OBVIOUS to me that I have free will. When I have just made a decision, say, to go to a concert, I feel that I could have chosen to do something else. Yet many philosophers say this instinct is wrong. According to their view, free will is a figment of our imagination. No one has it or ever will. Rather our choices are either determined—necessary outcomes of the events that have happened in the past—or they are random.
Our intuitions about free will, however, challenge this nihilistic view. We could, of course, simply dismiss our intuitions as wrong. But psychology suggests that doing so would be premature: our hunches often track the truth pretty well [see “The Powers and Perils of Intuition,” by David G. Myers; Scientific American Mind, June/July 2007]. For example, if you do not know the answer to a question on a test, your first guess is more likely to be right. In both philosophy and science, we may feel there is something fishy about an argument or an experiment before we can identify exactly what the problem is.
The debate over free will is one example in which our intuitions conflict with scientific and philosophical arguments. Something similar holds for intuitions about consciousness, morality, and a host of other existential concerns. Typically philosophers deal with these issues through careful thought and discourse with other theorists. In the past decade, however, a small group of philosophers have adopted more data-driven methods to illuminate some of these confounding questions. These so-called experimental philosophers administer surveys, measure reaction times and image brains to understand the sources of our instincts. If we can figure out why we feel we have free will, for example, or why we think that consciousness consists of something more than patterns of neural activity in our brain, we might know whether to give credence to those feelings. That is, if we can show that our intuitions about free will emerge from an untrustworthy process, we may decide not to trust those beliefs.
To discover the psychological basis for philosophical problems, experimental philosophers often survey people about their views on charged issues. For instance, scholars have argued about whether individuals actually believe that their choices are independent of the past and the laws of nature. Experimental philosophers have tried to resolve the debate by asking study participants whether they agree with descriptions such as the following:
Imagine a universe in which everything that happens is completely caused by whatever happened before it. So what happened in the beginning of the universe caused what happened next and so on, right up to the present. If John decided to have french fries at lunch one day, this decision, like all others, was caused by what happened before it.
When surveyed, Americans say they disagree with such descriptions of the universe. From inquiries in other countries, researchers have found that Chinese, Colombians and Indians share this opinion: individual choice is not determined. Why do humans hold this view? One promising explanation is that we presume that we can generally sense all the influences on our decision making—and because we cannot detect deterministic influences, we discount them.
Of course, people do not believe they have conscious access to everything in their mind. We do not presume to intuit the causes of headaches, memory formation or visual processing. But research indicates that people do think they can access the factors affecting their choices.
Yet psychologists widely agree that unconscious processes exert a powerful influence over our choices. In one study, for example, participants solved word puzzles in which the words were either associated with rudeness or politeness. Those exposed to rudeness words were much more likely to interrupt the experimenter in a subsequent part of the task. When debriefed, none of the subjects showed any awareness that the word puzzles had affected their behavior. That scenario is just one of many in which our decisions are directed by forces lurking beneath our awareness.
Thus, ironically, because our subconscious is so powerful in other ways, we cannot truly trust it when considering our notion of free will. We still do not know conclusively that our choices are determined. Our intuition, however, provides no good reason to think that they are not. If our instinct cannot support the idea of free will, then we lose our main rationale for resisting the claim that free will is an illusion.
Is Consciousness Just a Brain Process?
Though a young movement, experimental philosophy is broad in scope. Its proponents apply their methods to varied philosophical problems, including questions about the nature of the self. For example, what (if anything) makes you the same person from childhood to adulthood? They investigate issues in ethics, too: Do people think that morality is objective, as is mathematics, and if so, why? Akin to the question of free will, they are also tackling the dissonance between our intuitions and scientific theories of consciousness.
Scientists have postulated that consciousness is populations of neurons firing in certain brain areas, no more and no less. To most people, however, it seems bizarre to think that the distinctive tang of kumquats, say, is just a pattern of neural activation.
Our instincts about consciousness are triggered by specific cues, experimental philosophers explain, among them the existence of eyes and the appearance of goal-directed behavior, but not neurons. Studies indicate that people’s intuitions tell them that insects—which, of course, have eyes and show goal-directed behavior—can feel happiness, pain and anger.
The problem is that insects very likely lack the neural wherewithal for these sensations and emotions. What is more, engineers have programmed robots to display simple goal-directed behaviors, and these robots can produce the uncanny impression that they have feelings, even though the machines are not remotely plausible candidates for having awareness. In short, our instincts can lead us astray on this matter, too. Maybe consciousness does not have to be something different from—or above and beyond—brain processes.
Philosophical conflicts over such concepts as free will and consciousness often have their roots in ordinary intuitions, and the historical debates often end in stalemates. Experimental philosophers maintain that we can move past some of these impasses if we understand the nature of our gut feelings. This nascent field will probably not produce a silver bullet to fully restore or discredit our beliefs in free will and other potential illusions. But by understanding why we find certain philosophical views intuitively compelling, we might find ourselves in a position to recognize that, in some cases, we have little reason to hold onto our hunches.
The Quantum Physics of Free Will
Do we have autonomy, or are our choices preordained? Is that a false choice? And what, if anything, does physics have to say about that?
Is the fact you are reading this story a decision you arrived at it by your own free choice, or was your interest programmed into the universe from the moment of the big bang? What makes free will such a fun topic is not only that it dives deep into physics, neuroscience, and philosophy, but also that we all feel we have a direct stake in the answers.
Part of my own interest is that I've never been able to see why people get worked up about a supposed conflict between free will and determinism. To my mind, there is no conflict. Human consciousness and therefore the concept of free will are emergent properties, so whether microscopic physics is deterministic or not is irrelevant. To speak of a conflict is to mix levels of description. In other words, there's no "you" who is steered one way or the other by initial conditions. "You" are a product of those conditions. I developed this idea in the September 2015 issue of Scientific American, which is behind a paywall.
I'll grant that all this depends on what precisely we mean by “free will.” To me, it is the fact that you make choices. To others, though, free will involves some inherent unpredictability. In that case, it might well have something to do with the deep laws of nature. Within quantum mechanics, there are four basic arguments for such a connection:
1. Quantum mechanics is indeterministic, in that the outcomes of measurements are chosen at random from the slate of possibilities. So, if quantum effects help to shape our conscious choices, they sever the connection between us and the initial conditions of the universe.
2. When we conduct experiments on quantum particles, we exercise our free will—for example, we make choices about what precisely to ask of the particles. Or at least we think we exercise our free will. How those particles respond can depend on whether we really do.
3. If you could predict someone’s decisions consistently, you could conclude that he or she lacks free will. To do that, you’d need to take a full brain scan and simulate his or her thought processes. Yet quantum physics forbids the reliable, nondestructive copying of particles, let alone whole brains. If you could never observe the loss of free will, then you should doubt whether it is ever really lost.
4. Quantum physics is time-symmetric, so we are as justified in saying that our choices set the cosmic initial conditions as the other way round.
Here, I'll examine each of these contentions. This is an evolving document. Over time, I'll gradually flesh out the points and add interesting new contributions to the debate.
The question of free will is obviously one of the oldest in philosophy.
Argument #1: Quantum Indeterminism
I find the idea that indeterminism restores free will extremely unpersuasive. What difference does it make if my conscious choices were programmed in at the big bang or decided on the fly by random particle events? In either case, you might worry that your decisions are not your own. If anything, quantum indeterminism makes matters worse, because within our decision-making process, we want determinism: your choices should flow from your needs and desires.
Also, at a deep level, quantum mechanics is not random at all. Schrödinger’s equation is completely deterministic and time-symmetric.
In recent years, a number of philosophers—notably Jeremy Butterfield, Daniel Dennett, and Christian List—have fleshed out the compatibilist view by distinguishing among levels of description. Human cognition involves different structures than atomic physics and is governed by different laws, so determinism at micro level need not imply determinism at the agential level.
Meanwhile, others such as physicist Seth Lloyd and philosopher Jenann Ismael have argued that we have free will because it is impossible for us to know our own decisions before we make them.
Others, though, do see a role for quantum indeterminism. They include many of the scientists and philosophers who pioneered quantum mechanics, such as Max Born, Pascual Jordan, and Karl Popper. Born wrote to Einstein, ”To me a deterministic world is quite abhorrent—this is a primary feeling.” Conversely, Einstein’s preference for determinism may have reflected his thoughts on free will and moral responsibility. He wrote to Indian poet Rabindranath Tagore, ”Leaving aside the inconsistency of such a review, the influence of alcohol and other sharply controllable factors on our thoughts, feelings, and activities, should show very distinctly that determinism does not stop before the majesty of our human will.”
More recently, quantum-gravity theorist and blogger Sabine Hossenfelder has offered some thoughts. In a 2012 paper, she suggests that there is a third way between determinism and randomness: what she calls “free-will functions,” whose outputs are fully determined but unpredictable. Only those who know the function know what will happen. This is distinct from deterministic chaos, in which the function is universally known but the initial conditions are imperfectly known.
My first reaction was that the free-will function is operationally the same as a classical deterministic hidden variable—namely, there is a deterministic description of a system, even if we can’t tell what it is. After chatting with Hossenfelder, I think her point is that whereas hidden variables are part of the state of the system, the free-will function is part of the laws of nature. It is not a hidden variable, but a hidden law. Nature still meets the definition of determinism—a given state evolves in a definite way—even if the rules guiding evolution are unknowable. The free-will function might not be definable as an equation or algorithm, but would be what theoretical computer scientists call an oracle.
Argument #2: Quantum Contextuality and Nonlocality
Another connection to free will hinges on the phenomenon of entanglement. Does the spookily coordinated behavior of quantum particles reflect a nonlocal connection between them or, alternatively, some built-in cheat sheet that allows them to arrange their answers in advance? In the 1960s the Irish physicist John Bell devised an experiment to decide between these possibilities.
Free Will May Just Be the Brain's 'Background Noise,' Scientists Say
It's a question that has plagued philosophers and scientists for thousands of years: Is free will an illusion?
Now, a new study suggests that free will may arise from a hidden signal buried in the "background noise" of chaotic electrical activity in the brain, and that this activity occurs almost a second before people consciously decide to do something.
Though "purposeful intentions, desires and goals drive our decisions in a linear cause-and-effect kind of way, our finding shows that our decisions are also influenced by neural noise within any given moment," study co-author Jesse Bengson, a neuroscientist at the University of California, Davis, wrote in an email to Live Science. "This random firing, or noise, may even be the carrier upon which our consciousness rides, in the same way that radio static is used to carry a radio station."
This background noise may allow people to respond creatively to novel situations, and it may even give human behavior the "flavor of free will," Bengson said. [The 10 Greatest Mysteries of the Mind]
Predetermined or random
Sir Isaac Newton's laws of classical mechanics suggested the universe was deterministic, with an inevitable effect for every cause. By Newtonian logic, a "freely" made decision is completely predetermined by the actions that precede it.
But quantum physics revealed that subatomic particles' behavior is inherently unpredictable. As a result, physical forces like gravity and electromagnetism can't completely dictate the future based on past events, thus leaving a tiny window for free will to operate through the random behavior of subatomic particles.
Still, many philosophers doubted that the random behavior of miniscule particles could translate to free will, because quantum effects don't hold much sway at larger scales.
Experiments performed in the 1970s also raised doubts about human volition. Those studies, conducted by the late neuroscientist Benjamin Libet, revealed that the region of the brain that plans and executes movement, called the motor cortex, fired prior to people's decision to press a button, suggesting this part of the brain "makes up its mind" before people's' conscious decision making kicks in.
To understand more about conscious decision making, Bengson's team used electroencephalography (EEG) to measure the brainwaves of 19 undergraduates as they looked at a screen and were cued to make a random decision about whether to look right or left. [10 Surprising Facts About the Human Brain]
When people made their decision, a characteristic signal registered that choice as a wave of electrical activity that spread across specific brain regions.
But in a fascinating twist, other electrical activity emanating from the back of the head predicted people's decisions up to 800 milliseconds before the signature of conscious decision making emerged.
This brain activity wasn't strictly a signal at all — it was "noise," part of the brain's omnipresent and seemingly random electrical firing. In fact, neuroscientists usually consider this background noise meaningless and subtract it when trying to figure out the brain response to a specific task, said Rick Addante, a neuroscientist at the University of Texas at Dallas who was not involved in the research.
In other words, some hidden signal in the background noise of the brain seemed to determine people's conscious decisions before they made them.
"That's what's wild about it; it's not all noise," Addante told Live Science. "The question then becomes, what is it, and what is the information that it contains?"
The new study doesn't prove or disprove free will, Addante said.
"If there's something else occurring before our conscious awareness that's contributing to our decision, that raises the question about the extent of our free will," Addante said. On the other hand, the findings might open the door to free will by suggesting it rides on, but isn't quite the same as, the random background noise in our brains, he said.
But Ali Mazaheri, a neuroscientist at the University of Amsterdam in the Netherlands, sees the results as a blow to true free will.
The findings suggest that previous biases in the firing of the brain's sensory processing systems add up, leading people to decisions that the conscious brain later follows, said Mazaheri, who was not involved in the study.
But if free will is an illusion, why does it feel so real?
Though that's still a mystery, one theory is that life would be too depressing without the illusion of choice, making it hard for humans to survive and reproduce.
"The idea is that you have the illusion of free will as an artifact to be able to get through life," Mazaheri told Live Science.
The new findings were published in April in the Journal of Cognitive Neuroscience.
Humans have debated the issue of free will for millennia. But over the past several years, while the philosophers continue to argue about the metaphysical underpinnings of human choice, an increasing number of neuroscientists have started to tackle the issue head on — quite literally. And some of them believe that their experiments reveal that our subjective experience of freedom may be nothing more than an illusion. Here's why you probably don't have free will.
Indeed, historically speaking, philosophers have had plenty to say on the matter. Their ruminations have given rise to such considerations as cosmological determinism (the notion that everything proceeds over the course of time in a predictable way, making free will impossible), indeterminism (the idea that the universe and our actions within it are random, also making free will impossible), and cosmological libertarianism/compatibilism (the suggestion that free will is logically compatible with deterministic views of the universe).
Now, while these lines of inquiry are clearly important, one cannot help but feel that they're also terribly unhelpful and inadequate. What the debate needs is some actual science — something a bit more...testable.
And indeed, this is starting to happen. As the early results of scientific brain experiments are showing, our minds appear to be making decisions before we're actually aware of them — and at times by a significant degree. It's a disturbing observation that has led some neuroscientists to conclude that we're less in control of our choices than we think — at least as far as some basic movements and tasks are concerned.
At the same time, however, not everyone is convinced. It may be a while before we can truly prove that free will is an illusion.
Neuroscientists first became aware that something curious was going on in the brain back in the mid 1960s.
German scientists Hans Helmut Kornhuber and Lüder Deecke discovered a phenomenon they dubbed "bereitschaftspotential" (BP) — a term that translates to "readiness potential." Their discovery, that the brain enters into a special state immediately prior to conscious awareness, set off an entirely new subfield.
After asking their subjects to move their fingers (what were self-initiated movements), Kornhuber and Deecke's electroencephalogram (EEG) scans showed a slow negative potential shift in the activity of the motor cortex just slightly prior to the voluntary movement. They had no choice but to conclude that the unconscious mind was initiating a freely voluntary act — a wholly unexpected and counterintuitive observation.
Needless to say it was a discovery that greatly upset the scientific community who, since the days of Freud, had (mostly) adopted a strictly deterministic view of human decision making. Most scientists casually ignored it.
But subsequent experiments by Benjamin Libet in the 1980s reinforced the pioneering work of Kornhuber and Deecke. Similarly, Libet had his participants move their fingers, but this time while watching a clock with a dot circling around it. His data showed that the readiness potential started about 0.35 seconds earlier than participants' reported conscious awareness.
He concluded that we have no free will as far as the initiation of our movements are concerned, but that we had a kind of cognitive "veto" to prevent the movement at the last moment; we can't start it, but we can stop it.
From a neurological perspective, Libet and others attributed the effect to the SMA/pre-SMA and the anterior cingulate motor areas of the brain — an area that allows us to focus on self-initiated actions and execute self-instigated movements.
Modern tools show the same thing
More recently, neuroscientists have used more advanced technologies to study this phenomenon, namely fMRIs and implanted electrodes. But if anything, these new experiments show the BP effect is even more pronounced than previously thought.
For example, a study by John-Dylan Haynes in 2008 showed a similar effect to the one revealed by Libet. After putting participants into an fMRI scanner, he told them to press a button with either their right or left index fingers at their leisure, but that they had to remember the letter that was showing on the screen at the precise moment they were committed to their movement.
The results were shocking. Haynes's data showed that the BP occurred one entire second prior to conscious awareness — and at other times as much as ten seconds. Following the publication of his paper, he told Nature News:
The first thought we had was 'we have to check if this is real.' We came up with more sanity checks than I've ever seen in any other study before.
The cognitive delay, he argued, was likely due to the operation of a network of high-level control areas that were preparing for an upcoming decision long before it entered into conscious awareness. Basically, the brain starts to unconsciously churn in preparation of a decision, and once a set of conditions are met, awareness kicks in, and the movement is made.
In another study, neuroscientist Itzhak Fried put aside the fMRI scanner in favor of digging directly into the brain (so to speak). To that end, he implanted electrodes into the brains of participants in order to record the status of individual neurons — a procedure that gave him an incredibly precise sense of what was going on inside the brain as decisions were being made.
His experiment showed that the neurons lit up with activity as much as 1.5 seconds before the participant made a conscious decision to press a button. And with about 700 milliseconds to go, Fried and his team could predict the timing of decisions with nearly 80% accuracy. In some scenarios, he had as much as 90% predictive accuracy.
Different experiment, similar result.
Fried surmised that volition arises after a change in internally generated fire rates of neuronal assemblies cross a threshold — and that the medial frontal cortex can signal these decisions before a person is aware of them.
"At some point, things that are predetermined are admitted into consciousness," he told Nature, suggesting that the conscious will might be added on to a decision at a later stage.
And in yet another study, this one by Stefan Bode, his detailed fMRI experiments showed that it was possible to actually decode the outcome of free decisions for several seconds prior to it reaching conscious awareness.
Specifically, he discovered that activity patterns in the anterior frontopolar cortex (BA 10) were temporally the first to carry information related to decision-making, thus making it a prime candidate region for the unconscious generation of free decisions. His study put much of the concern about the integrity of previous experiments to rest.
But not everyone agrees with the conclusions of these findings. Free will, the skeptics argue, is far from debunked.
Back in 2010, W. R. Klemm published an analysis in which he complained about the ways in which the data was being interpreted, and what he saw as grossly oversimplified experimentation.
Others have criticized the timing judgements, arguing about the short timeframes between action and movement, and how attention to aspects of timing were likely creating distortions in the data.
It's also possible that the brain regions being studied, namely the pre-SMA/SMA and the anterior cingulate motor areas of the brain, may only be responsible for the late stages of motor planning; it's conceivable that other higher brain systems might be better candidates for exerting will.
Also, test subjects — because of the way the experiments were set up — may have been influenced by other "choice-predictive" signals; the researchers may have been measuring brain activity not directly related to the experiment itself.
The jury, it would appear, is still out on the question of free will. While the neuroscientists are clearly revealing some important insights into human thinking and decision making, more work needs to be done to make it more convincing.
What would really settle the issue would be the ability for neuroscientists to predict the actual outcome of more complex decisions prior to the subject being aware of it themselves. That would, in a very true sense, prove that free will is indeed an illusion.
Furthermore, neuroscientists also need to delineate between different types of decision-making. Not all decisions are the same; moving a finger or pressing a button is very different than contemplating the meaning of life, or preparing the words for a big speech. Given the limited nature of the experiments to date (which are focused on volitional physical movements), this would certainly represent a fruitful area for inquiry.
Blurring science, philosophy, and morality
Moreover, there's also the whole issue of how we're supposed to reconcile these findings with our day-to-day lives. Assuming we don't have free will, what does that say about the human condition? And what about taking responsibility for our actions?
Daniel Dennett has recently tried to rescue free will from the dustbin of history, saying that there's still some elbow room for human agency — and that these are still scientific questions. Dennett, acknowledging that free will in the classic sense is largely impossible, has attempted to reframe the issue in such a way that free will can still be shown to exist, albeit under certain circumstances.
There's still a lot of naïve thinking by scientists about free will. I've been talking about it quite a lot, and I do my best to undo some bad thinking by various scientists. I've had some modest success, but there's a lot more that has to be done on that front. I think it's very attractive to scientists to think that here's this several-millennia-old philosophical idea, free will, and they can just hit it out of the ballpark, which I'm sure would be nice if it was true.
It's just not true. I think they're well intentioned. They're trying to clarify, but they're really missing a lot of important points. I want a naturalistic theory of human beings and free will and moral responsibility as much as anybody there, but I think you've got to think through the issues a lot better than they've done, and this, happily, shows that there's some real work for philosophers.
Dennett, who is mostly responding to Sam Harris, has come under criticism from people who complain that he's being epistemological rather than scientific.
Indeed, Sam Harris has made a compelling case that we don't have it, but that it's not a problem. Moreover, he argues that the ongoing belief in free will needs to come to an end.
A person's conscious thoughts, intentions, and efforts at every moment are preceded by causes of which he is unaware. What is more, they are preceded by deep causes — genes, childhood experience, etc. — for which no one, however evil, can be held responsible. Our ignorance of both sets of facts gives rise to moral illusions. And yet many people worry that it is necessary to believe in free will, especially in the process of raising children.
Harris doesn't believe that the illusoriness of free will is an "ugly truth," nor something that will forever be relegated to philosophical abstractions. This is science, he says, and it's something we need to come to grips with. "Recognizing that my conscious mind is always downstream from the underlying causes of my thoughts, intentions, and actions does not change the fact that thoughts, intentions, and actions of all kinds are necessary for living a happy life — or an unhappy one, for that matter," he writes.
But as Dennett correctly points out, this is an issue that's far from being an open-and-shut case. Advocates of the "free will as illusion" perspective are still going to have to improve upon their experimental methods, while also addressing the work of philosophers, evolutionary biologists — and even quantum physicists.
Why, for example, did humans evolve consciousness instead of zombie-brains if consciousness is not a channel for exerting free will? And given the nature of quantum indeterminacy, what does it mean to live in a universe of fuzzy probability?
There's clearly lots of work that still needs to be done.
Neuroscience of free will, a part of neurophilosophy, is the study of the interconections between free will and neuroscience.
As it has become possible to study the human living brain, researchers have begun to watch decision making processes at work. Findings could carry implications for our sense of agency, moral responsibility, and our understanding of consciousness in general. One of the pioneering studies in this domain was designed by Benjamin Libet, while other studies have attempted to predict participant actions before they make them. Taken together, these various studies show that at least some actions - like moving a finger - are initiated unconsciously at first, and enter consciousness afterward. Unconscious processes (e.g. habits or training) are the prime movers in such cases.
Some areas of the human brain implicated in mental disorders that might be related to free will. Area 25 refers to Brodmann's area 25, related to long-term depression.
The field remains highly controversial. There is no consensus among researchers about the significance of findings, their meaning, or what conclusions may be drawn. It has been suggested that consciousness mostly serves to cancel certain actions initiated by the unconscious. On this model, consciousness is understood to have "veto" power over our behavior. However even the act of "vetoing" has been shown to be unconsciously initiated in some cases. An action like running a red light may be initiated, then vetoed in miliseconds, all unconsciously. The precise role of consciousness in decision making therefore remains unclear.
Thinkers like Daniel Dennett or Alfred Mele worry about the language used by researchers. They explain that "free will" means many different things to different people (e.g. some notions of free will are dualistic, some not). Dennett insists that many important and common conceptions of "free will" are compatible with the emerging evidence from neuroscience.