The experiments of Benjamin Libet. Do we have free will?

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Free will problem​

The issue of free will is the most burning issue in all spheres of science - from philosophy to biology. Each scientist or philosopher, in one way or another, offers more and more new positions regarding this concept.

Arthur Schopenhauer, for example, proposed to consider a person as an executor of the blind "World Will", classical psychoanalysis, based on the ideas of the latter, developed this into a whole system, humanistic psychological theories, as opposed to the views of psychoanalysts (oh yes, even behaviorists) consider a person to be an independent being.

But suddenly, at some point, will ceases to be a concept of pure logical abstraction and turns into a measurable electrical potential. The concept of will is no longer just an object of abstract reasoning or humanitarian theories, but all thanks to the controversial and controversial experiment of Benjamin Libet, which he conducted in 1973.

A bit of history​

Benjamin Libet (1916-2007) - a pioneer of research in the field of neurosciences, it was thanks to a series of his experiments that the problem of free will reached a different level. Libet's idea for the experiment arose after he got acquainted with the results of studies by the German neurophysiologists Hans Helmut Kronhuber and Lüder Decke from the University of Freiburg, published by them in 1964.

According to these studies, voluntary hand movements are preceded by changes in the electrical activity of the motor cortex (they conducted an experiment very similar to the one that Libet later did). The signal was recorded using electrodes from the parietal part of the skull and appeared about a second before the start of the action (to be precise, 800 ms). It has been called the premotor potential or readiness potential.

These discoveries caused great excitement and controversy in the scientific community of the time, and Nobel laureate Sir John Carew Eccles (John Carew Eccles) even suggested that a conscious desire (will) should be ahead of a voluntary action by about 1 second. It happened in the late 1970s. at one of the discussions on the problem of free will, in which Libet took part. As Michael Brooks writes, it was then that Libet began to think about how to test Ackles' hypothesis empirically.

How did the experiment go?​

And, as you might guess, Libet found a solution that later became a milestone in the history of neuroscience. As part of his experiment, the scientist decided to use an oscilloscope (it is usually used to measure the evoked potential, and the readiness potential (hereinafter PG) is one of the methods for measuring the evoked potential). On the round screen of the oscilloscope, the point of light ran like a clock hand, only 25 times faster, and the screen itself looked like an ordinary dial with divisions of 5, 10, 15 ... 55 seconds.

The subject, in turn, had to follow the point of light, and, as soon as he had a desire to bend the wrist, remember where the point of light was at that moment. Accurate readings of the time of arm muscle contraction were taken using an electromyogram (EMG) - in other words, electrodes were attached to the arm.

What did the experiments show?​

Without going into details, Libet's experiments showed the following:
- first the potential for readiness appeared;
- then, after about 350 ms, the subject consciously made the decision to move his brush (this was recorded by the time on the dial in front of him);
- after about 100 ms, there was a signal from the wrist of the hand.

What does it mean? So this is the following: our perception of life is delayed by almost half a second and, as Libet himself said: "we make all quick decisions unconsciously." It doesn't seem like much fun yet, does it? Kind of like an experiment proved that we do not have and never had free will? Then, in the 80s, these data caused a furor, and some scientists even considered them proof of our lack of free will.

But, oddly enough, Libet himself did not think so. Of course, in his opinion, “consciousness cannot initiate action,” but free will exists, since after realizing the desire, a person still has 100 ms to “veto” the impulse. That is, we do not consciously make decisions, our unconscious does it for us, but the role of free will and consciousness is to implement or not to implement the incipient urge. These findings forced Libet to conduct yet another series of experiments to confirm the presence or absence of the ability to veto an action. During the experiments, the participants were instructed to plan an action at a certain point, but then not to take it. In these experiments, the action was not performed, but still a PG appeared, indicating that it was freely planned, but was interrupted.

It is important to understand this: PG precedes only free conscious actions. In the case of uncontrolled or automatic behavior, such as Tourette's syndrome or an unexpected reaction to a stimulus, PG does not appear. Curiously, even such complex actions as writing and speaking are preceded by PG, perhaps we can assume that our unconscious in some incomprehensible way gives most of the meanings that then emerge in our consciousness.

Criticism of experiments​

Most often, Libet is criticized for the fact that in the course of his experiments he uses the concepts urge, wanting, wish, decision interchangeably. According to Alfred Mele (professor of philosophy at Florida State University), this leads to confusion. “Most people recognize that deciding to do something is different from having the urge or desire to do something. For example, you may have the urge to yell at an annoying coworker, but decide not to. And you may want a second serving of dessert, but decide to stick with one, ”says Mele.

This is how Mele defines a decision: a decision is a conscious formation of intention in a situation of uncertainty, a free choice of an option of action. And it is worth agreeing that in this vein, the decision and the desire or motivation are far from the same, and between these concepts there is a huge gap. The main conclusion that Mele makes in the course of his reflections is this: the decision cannot be unconscious, since the participation of consciousness is necessary for its adoption.

In this situation, freedom of will is not threatened, even if we understand it in terms of Libet, but it is important to note the following: Mele and Libet have fundamentally different positions regarding this concept. Mele adheres to the compatibilist position, its essence lies in the fact that the physicochemical determination of mental processes does not prevent the subject from having free will. Libet, on the other hand, adheres to the position of incompatibilism (within the framework of this position, it is believed that free will is incompatible with determinism and has metaphysical grounds).

In the end, the distinction between impulses and desires on the one hand and decisions on the other looks quite convincing. One can only wonder if Libet didn't think about it when he was hatching the idea of the experiment, because it's almost obvious that decision and desire are not the same. It seems that in order to possess the skills of such a subtle terminological distinction, one must have a philosophical base, which Libet did not possess. But what if not everything is so simple, and the scientist intentionally decided not to distinguish between terms, understanding the complexity of the conceptual distinction between motives, desires, intentions and decisions? Be that as it may, these experiments have become the basis for a lot of controversy, assumptions and the impetus for a whole series of studies, which is important in itself.