Free will is an illusion, right? 

Have you heard that free will is an illusion? Have you heard that this is what neuroscience tells us? I am a neuroscientist, and I am not that sure.

How is free will defined?

It feels natural that while I am typing these words, I am exercising my will. How free am I in my choice of what to write? Is it even a legitimate question to begin with? Philosophers define free will with two principles: 1) I should be the source of my actions; and 2) I should be able to choose to act otherwise or not to act at all.  I agree with these criteria; however, they are not directly testable in experimental settings. What we can do as scientists is ask a participant to act as she chooses and then observe, interview, and record brain activity. Every once in a while, it is useful to acknowledge that what we want to discover is actually very different from what we are observing.

What do neuroscientists think they know about free will?

From a third-person perspective, the act of willing cannot be observed directly. Rather, we can assume that willing is expressed via volitional movements (also known as self-initiated movements or self-paced movements). The empirical approach to studying volition has its roots in experiments by Benjamin Libet in the 1980s. In the series of studies, it was demonstrated that 1-2 seconds before internally generated, spontaneous movement, the brain's electrophysiological records show a prominent decrease in voltage over the central regions. This decrease, however, starts earlier than the time when the participant reports having an urge to move. The conclusion followed that the brain had made a decision and then fed it into consciousness; hence, conscious free will does not exist. And that was what made to the headlines.

What do they actually know?

In reality, it is complicated.

The typical run of Libet’s experiment is the following: participants are asked to attend to their inner lives and look for spontaneous urges to move. Whenever participants feel an urge, they should make a movement. The time of the urge (or decision to move, or intention) is of particular interest. Participants would estimate the time of their conscious decision to move using a clock with a moving dot. The clock has a period of rotation of about 2.5 seconds. Upon the urge or the decision, the participant is supposed to remember the location of the dot and report it after the movement has been performed. 

However, it is not necessarily clear what participants report. For instance, it's quite possible that they are using some logic to come up with time estimates that seem sensible. One string of research attempts to understand how accurate the time reported is. For the latest study, see Bredikhin et al., Neuropsychologia (2023), or Ivanof et al., Scientific Reports (2022).

The Libet experiment itself is rather demanding. As a participant, you have to monitor your inner urges, monitor the clock, and store its position when needed; moreover, you are under pressure to produce spontaneity. Another string of research attempts to estimate the contribution of processes related to all non-volitional activities that accompany the act of volitional movement. For example, Miller et al., Psychological Science (2011).

Lastly, in our everyday lives, we do not really feel urges to move; we just move; we use movement to achieve a goal. And even if I have an urge to eat chocolate, I will reach for a chocolate bar, thus fulfilling an urge to eat chocolate but not an urge to move per se. Some would go as far as to claim that the urge to move, if it exists, occurs on a subpersonal level. Therefore, yet another string of research searches for new experimental paradigms to access volition. This string is my personal favorite; in particular, I admire the work of Prof. Dr. Patrick Haggard in this direction.

Take home

Current evidence from cognitive science does not either confirm or disprove free will. In my opinion, there is a huge gap between the concept of determinism that stems from physics and what we try to measure in experiments with human participants. The best thing we can do is keep sprouting ideas. Although maybe we would rather leave Libet’s paradigm and the buzz around it behind.

September, 2023