Opinion – Luciano Melo: The human brain is rational, yes; free will exists

Physiologist Benjamin Libet wanted to understand how the brain commands bodily movements. In 1983, he recruited volunteers for a survey and instructed them to flex their wrists or move their fingers whenever they wished. Participants had electrodes on their scalps, so brain activity was continuously monitored. They should look at a computer screen that displayed a dot around a clock bezel. As soon as they felt like moving, they should record the exact position occupied by the point.

When analyzing the data, a surprise, the scientist discovered that the brain was getting ready to perform the movement before there was a conscious desire to do so. The researcher’s conclusion: the brain initiation of a spontaneous voluntary act begins unconsciously. Some technicians thought that there was proof of the inexistence of free will.

However, Libet himself chose not to agree with this premise. He argued that a conscious veto that aborts spontaneously initiated actions would be possible. And he continued: we humans can act with independence, freedom of choice and, there is evidence in sight, that consciousness can control some brain processes.

Despite these warnings, the neuroscientist was no longer in control of the unfolding of his experiment. The concepts that the brain decides before the Self decides and that consciousness is a by-product and, at the same time, a puppet of instinctive brain mechanisms, had already jumped the laboratory frontiers.

These ideas were co-opted by a folk neuroscience, but capable of influencing prominent thinkers. As the psychologist John Kihlstrom of the University of California recalls, when he quotes the passage from the book Homo Deus, written by the historian and writer Yuval Harari, author of “Sapiens”: “science ends liberalism, arguing that individual freedom is just a fictional tale, invented by a set of biochemical algorithms”.

And also when he mentions the psychologist Daniel Wegner, who in the work “The Illusion of the Conscious Will” wrote: “the brain creates both action and thought, but leaves the person to infer that the thought created the movement”. Search YouTube, in newspaper search engines, you will see that Benjamin Libet’s experiment is pop.

But between us, doesn’t it seem an exaggeration to generalize that there is no free will from the study of such trivial gestures as the shaking of fingers or wrists? Now, purposeless movements are quite different from complicated actions in complex contexts.

Also remember, in 1983, technology to investigate the brain was in its infancy. Forty years have passed and innovations have been incorporated into the neurosciences. This fact created spaces for new, more robust experiments to properly review the experience of the point on the clock. Scientists then noticed that the intention to move comes before neural activity, which Libet considers to be preparatory to movement.

But there is an icing on the cake, the discovery of neurotechnology researcher Kramay Patel, from the University of Toronto. He demonstrated how human volition can modify the activity of a single brain neuron. In one of his scientific investigations, patients were instructed to vertically move a red square displayed on a computer screen, using mental commands. The position of the square depended exclusively on the electrical activity of a single brain neuron, connected directly to an electrode that had been surgically placed.

Participants were not instructed on how to move the red polygon, but they were able to learn on their own. So they modulated the activity of the neuron to make the square go up or down. Proof that consciousness can control some brain processes, that reason can command the brain.

Patel does not wish to prove whether or not free will exists. Instead, he values ​​developing the brain-machine interface, a matter that is simpler than saying whether reason moves us, or whether, on closer inspection, we are mere beasts dressed in superficial sophistication. I hope your experiment will help to develop new therapies, but also that it will leapfrog laboratory boundaries and become a topic for folk neuroscience.

References

1. Libet B, Wright EW, Gleason CA. Preparation- or intention-to-act, in relation to pre-event potentials recorded at the vertex. Electroencephalogr Clin Neurophysiol. 1983 Oct 1;56(4):367–72; 2. Neafsey EJ. Conscious intention and human action: Review of the rise and fall of the readiness potential and Libet’s clock. Conscious Cogn. 2021 Sep 1;94:103171; 3. Rubin DB, Paulk AC. Neuron, control thyself! Brain. 2021 Dec 1;144(12):3550–1; 4. Patel K, Katz CN, Kalia SK, Popovic MR, Valiante TA. Volitional control of individual neurons in the human brain. Brain. 2021 Dec 1;144(12):3651–63; 5. Kihlstrom JF. Time to lay the Libet experiment to rest: Commentary on Papanicolaou (2017). Psychol Conscious Theory Res Pract. 2017;4(3):324–9