A Scientist’s Defense of Free Will

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Synopsis

Why scientists should not jump to the unwarranted conclusion that free will is just an illusion.

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.

Amen.

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?

 

 

References :

Benjamin Libet 1983 Article : Time of Conscious Intention to Act in Relation to Onset of Cerebral Activity (Readiness-potential) The Unconscious Initiation of a Freely Voluntary Act

Benjamin Libet 1993 Article : Unconscious cerebral initiative and the role of conscious will in voluntary action.

Chun Siong Soon Article : Unconscious determinants of free decisions in the human brain

P.W. Anderson Article : More is Different: Broken symetry and the nature of the hererchical structure of science

 Robert B. Laughlin A Different Universe: Reinventing Physics from the Bottom Down

Laughlin's  Interview : Laughlin on the Future of Carbon and Climate

Tags: brain, consciousness, free will, libet experiment, mahir ozdemir, neursoscience

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