Matthew MacKinnon MD

MindfulnessMD

Illusion of Choice: The Myth of Free Will

What does the neuroscience of free will tell us about this core assumption?

Posted Aug 28, 2016

Redd Angelo | Unsplash.com
Source: Redd Angelo | Unsplash.com

Before we begin I want you to wink.

Did you choose to wink your left or your right eye? Or did you choose at all?

If I asked you to explain the sequence of events that led to your wink you would likely tell me that you first heard and understood my request, then chose the eye that you were going to wink, and finally told your eyelid to close and open. The continuity of this reasoning is very pleasing to your sense of self because it reinforces the notion of free will.

Merriam-Webster’s Dictionary1 defines free will as “the ability to choose how to act.” The notion of free will is encapsulated in your subjective experience of having consciously chosen either the left or the right eye to wink. Although the existence of free will is treated as a self-evident fact by most, neuroscientific research suggests that there may be a more complex explanation to your wink and to the notion of free will than there appears at first glance.

Source: Steven Wei | Unsplash.com

Libet et al.2 authored a study in the early 1980s that has served as an academic foundation for years of subsequent research into the question of free will. I essentially replicated the experimental design when I asked you to arbitrarily choose an eye to wink. Libet et al. used an arm raise as their voluntary action, but the design was similar.

Findings from Libet’s experiment demonstrated that the conscious experience of having chosen a particular arm to raise occurred nearly 500 milliseconds after neural mechanisms involved in arm raising had already begun the process.2

Haggard and Eimer3 updated this experimental design and showed that the conscious experience of having initiated a voluntary action coincided not with the neural preparation for the action, but instead occurred later during the actual execution of the action. In other words, Haggard and Eimer showed that your brain chose which eye to wink before both your eye winked and before you had the conscious experience of having made a choice between left and right.

Finally, in a similar experimental design Soon et al.4 used fMRI technology to predict a participant’s action a staggering 8 seconds before an action was performed.

Source: Dino Reichmuth | Unsplash.com

Does all of this mean that we don’t have any free will? Not necessarily.

In his 2008 article in the journal Nature Reviews Neuroscience, Dr. Patrick Haggard5 suggested that the same neural networks involved in planning motor actions may also “plan” the experience of conscious intention. In our eye wink scenario, Dr. Haggard’s theory would suggest that the conscious experience of free will is the contemporary of the physical wink and not the initial choice of laterality.

So how would a neuroscientist describe the sequence of events leading up to your wink?

First, your comprehension of my request to wink triggered preparatory activity in your pre-supplemental motor area (pre-SMA) as well as in a group of related brain structures that make up a sort of volitional circuit in the brain.5,6 Because the choice of which eye to wink was largely arbitrary, your choice of left or right was likely a result of baseline random neural activity or maybe a habitual preference for laterality (maybe you most frequently wink with your right eye).

Let’s imagine for a moment that you did in fact go on to wink with your right eye. In that case, the pre-SMA and its associated structures generated both the neurological map for the planned movement (winking your right eye) and the outline of the conscious experience of intention (“I did this”). This information was then communicated to the motor cortex as well as to parts of the prefrontal cortex.6

The prefrontal cortex used this behavioral map to predict an expected action (“I’m going to wink my right eye”), while the motor cortex signaled the right eyelid to close and open.6 Your somatosensory cortex then received feedback from the body indicating that the predicted action had indeed occurred.6

It is at this point that you have the conscious experience of, “I chose to wink with my right eye.” The human brain is a logical machine and it seeks to establish linear causation regardless of the temporal reality. The fact that your prediction aligned with the actual action is interpreted by your brain to mean that your conscious thought caused the action. In reality, your thought, “I chose to wink my right eye,” is nothing more than a retroactive inference generated in an attempt to transmute a largely unconscious process into a conscious one.5

Angela Benito | Unsplash.com
Source: Angela Benito | Unsplash.com

Obviously, the decision to wink is far more complex when viewed through the eyes of a neuroscientist. But does any of this science matter if our subjective experience tells us that we are making a conscious, free choice?

I would suggest that the truth of our neural inner workings offers significant advantage over a blind faith in a linear notion of free will. We too often treat reality as an immovable fact. It is as if the world were ice and we were unable to see the liquid state inherent to its form.

Reality is as flexible and as pliable as the mind that we use to perceive it. The self-doubts, anxieties, and judgments that so often dominate our consciousness can be restructured using the same mental tools that our brain employs to retroactively insert the perception of free will.

Whether it be by psychotherapy, pharmacotherapy, or through a combination thereof, the utility of the brain’s inferential mechanisms extend far beyond generating a sense of free will. For example, behavioral activation (a form of therapy) works by creating the target healthy behavior before the thoughts obstructing the healthy behavior change.7 Because of the inferential function of the mind, enough repetition of the behavior causes the brain to generate the explanation, “I’m performing happy behaviors, therefore, I must be happy.” And just like with free will, we are inclined to believe our mind’s inductive reasoning.

Obviously, the complexities of sadness, anxiety, and other mental ills cannot be summed up in just a few paragraphs. I do not wish to suggest that cognitive restructuring is easy, rather, it is my hope that by revealing the plasticity of the human brain we can begin to dissolve the hopelessness that arises from a belief in mental rigidity.

References

  1. Merriam-Webster I. The Merriam-Webster Dictionary.; 2016.
  2. Libet B, Gleason CA, Wright EW, Pearl DK. Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act. Brain J Neurol. 1983;106 (Pt 3):623-642.
  3. Haggard P, Eimer M. On the relation between brain potentials and the awareness of voluntary movements. Exp Brain Res. 1999;126(1):128-133. doi:10.1007/s002210050722.
  4. Soon CS, Brass M, Heinze H-J, Haynes J-D. Unconscious determinants of free decisions in the human brain. Nat Neurosci. 2008;11(5):543-545. doi:10.1038/nn.2112.
  5. Haggard P. Human volition: towards a neuroscience of will. Nat Rev Neurosci. 2008;9(12):934-946. doi:10.1038/nrn2497.
  6. MacKinnon M. Neuroscience. Neuraptitude.org. http://neuraptitude.org/category/biology/neuroscience/. Published 2016.
  7. Dimidjian S, Hollon SD, Dobson KS, et al. Randomized trial of behavioral activation, cognitive therapy, and antidepressant medication in the acute treatment of adults with major depression. J Consult Clin Psychol. 2006;74(4):658-670. doi:10.1037/0022-006X.74.4.658.

To learn more about the inner workings of the human brain visit Neuraptitude.org

More Posts