Just across the street from the Mensa is the Bernstein Center for Computational Neuroscience (BCCN), where Professor John-Dylan Haynes’ group has conducted a remarkable experiment questioning the nature of conscious thoughts and intentions involved in our decisions [1] (Check out by Filip Morys).
Is free will just an illusion? This has been an old philosophical debate starting even before the term neuroscience was coined. The free will argument rests on the assumption that we consciously generate our own thoughts. The traditional counterargument against the free will proponent is philosophical materialism. Materialists claim that mental states can only change due to a change in brain activity, which is a physical system constrained by the laws of physics. Neuroscience studies reach beyond solely supporting the materialists’ argument. Even if we think of our minds as immaterial souls, this should not change how we view our volition. It does not matter whether unconscious activities are physical or divine in nature; they are still unconscious [2,3].
A bereitschaftspotential is detected before a subject consciously makes a decision
The shocking results of Dr. Haynes’ group are not an anomaly, but consistent with a history of similar experiments. In 1983, the prominent physiologist Benjamin Libet used EEG to show that a certain cortical motor activity known as Bereitschaftspotential is detected 300 milliseconds before a subject consciously decides to move. Recently, scientists from Harvard University have provided more compelling evidence using direct recording methods. Recording the activity of just 256 neurons in the motor cortex is sufficient to predict up to 80% of a subject’s voluntary decisions 700 milliseconds before being consciously aware of it [4]. These findings seem very difficult to reconcile with the common sense conception of free will. Every day, I think I make a conscious decision about my lunch - where and what I eat. Most probably, before I feel as if I am deciding, my neurons have already determined what I will do. You can imagine a fancy experiment where a mobile fMRI is fixed on my head and connected to a computer at the BCCN. If a researcher can know the place and type of food I am going to decide on 7 seconds before I consciously decide, how can I still think that I have free will? This applies not only to deliberate decisions, but also spontaneous intentions that pop up such as having tea after lunch. Why not coffee? I just do not know. I consciously witness my thoughts but I cannot influence them.
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In response to this support for determinism, philosophers’ approaches have been divided into two main streams in the free will-determinism debate [2,3]. Incompatibilists like Sam Harris think that free will is incompatible with determinism. If our intentions and decisions are predetermined unconsciously as shown by findings from neuroscience research, then free will is merely an illusion. For Harris, believing in free will and determinism is paradoxical, like claiming, “A puppet is free as long as he loves his strings” [2]. On the other hand, compatibilists such as prominent philosopher Daniel Dennett assume no contradiction between free will and determinism; neuroscientific findings do not by any means invalidate this compatibility [4]. The compatibilist view prompts me to think of Pinocchio in the famous novel “The Adventures of Pinocchio” by Carlo Collodi. Pinocchio is a wooden puppet turned into a real boy. He consciously makes decisions. However, Pinocchio is determined by his wooden nature and by the fact that his nose grows when he lies.
The debate is lead by two parties, the incompatibilists and the compatibilists
Despite their different opinions, Dennett agrees with Harris that we do not consciously access at least part of our neural processes involved in making decisions. However, these unconscious neurophysiological processes are still our own as much as other conscious neural processes. We have to avoid setting up a dichotomy between our conscious self and other aspects of our brain's neurophysiology. As conscious beings, we really deliberate, decide and act, even if part of this process is cooked up unconsciously. This does not entail any incoherence in the concept of free will. I might not know why I intended to drink a cup of tea after lunch; I only witness my thoughts consciously, but I can also interfere with them unconsciously by continuing to remind myself. It is only the stage when my brain is evaluating different inputs in order to make a choice that I cannot influence. You might be partially unconscious of your brain processes while being in control of your actions. When driving a car you are in control even if you are not attentive to details. You know that your unconscious intentions will generally make the right decisions to get you home safely. It is this reflexive repetitive nature of our thinking that maintains an indirect control over our brains’ decisions [3].
The complexity of the free will debate reflects the enigmatic nature of how we perceive ourselves as conscious, mindful, and rational beings in a world consisting of mindless, unconscious, and unperceptive physical matter. The notion of free will is easy to accept intuitively, as we feel a genuine authorship of our own thoughts, and this feeling is what gives life some of its sweet, and sometimes sour, taste.
[1] Soon et al, Nature Neurosci, 2008
[2] Harris, Free will, 2012
[3] Dennett, Freedom evolves, 2003
[4] Fried et al, Neuron, 2011
By Mostafa Nashaat Abdelhamid, PhD Alumni Berlin School of Mind and Brain
this article originally appeared 2014 in CNS Volume 7, Issue 1, Mind and Brain
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