Do we genuinely possess free will – are we the executors or spectators of our own actions?

One of the most debated questions in biology concerns whether human behavior is genetically determined or shaped by experience, with a focus on the relative significance of biology compared to culture and environment. Experts argue that most human behaviors can be explained by brain function, genetics, and evolutionary processes. This viewpoint raises concerns that attributing behavior solely to biology negates the ability to hold others accountable for their actions.

Advancements in neurobiology now allow us to monitor and analyze brain activity in real time, providing a valuable tool for investigating the concept of free will. In the 1980s, Benjamin Libet conducted groundbreaking research focusing on identifying the functional potential in the cerebral cortex when individuals made seemingly arbitrary decisions about movement. It was discovered that this potential arises approximately half a second before the subjects became consciously aware of their decision. These findings supported philosophical theories suggesting that consciousness merely serves a regulatory role, while the energy required for movement originates in the unconscious. Subsequent experiments demonstrated that human decisions can be predicted based on bioelectrical potentials in the brain before they are consciously made.

Under certain brain-related conditions, individuals are unable to fully control their actions. While the existence of such conditions does not directly refute the presence of free will, studying them, as in the aforementioned studies, aids in developing models that illustrate how the brain generates our experiences of freedom. For instance, individuals with Tourette syndrome and related disorders perform involuntary movements and sounds, known as tics, despite preferring to avoid them. Tics are described as semi-voluntary or "unwanted" because they are not entirely involuntary: they can be experienced as a desired response to an unwanted preceding urge. Tics are perceived as an irresistible urge that must ultimately be expressed. People with Tourette syndrome can sometimes delay tics, but this often results in a later, more intense manifestation. Sustained control (from seconds to occasionally entire hours) merely postpones and intensifies the subsequent tic expression. In the alien hand syndrome, the affected limb performs purposeful behaviors without conscious intent. Consequently, the affected limb appears to exhibit "its own will." The sense of control does not arise in conjunction with the overt execution of an intended action, although the sense of bodily ownership is preserved. This phenomenon correlates with a weakening of the readiness potential, manifesting over time through the emergence of a readiness potential recorded on the scalp hundreds of milliseconds before the overt occurrence of a spontaneous, voluntary movement. Using fMRI to examine the temporal dimension of cortical activation networks associated with voluntary movement in humans, a sequential activation process "from predecessor to successor" is observed, beginning in the so-called supplementary motor area (SMA) on the medial surface of the frontal lobe and extending to the primary motor cortex, followed by the parietal lobe. Thus, the sense of control appears to normally arise alongside this ordered sequential activation network, encompassing premotor associative centers along with the primary motor cortex. In particular, the supplementary motor area on the medial surface of the frontal lobe seems to activate before the primary motor cortex, likely in connection with the preparatory premotor process. In a recent fMRI study, alien movements were characterized by relatively isolated activation of the primary motor cortex on the opposite side of the alien hand, whereas voluntary movements of the same body part were accompanied by activation of motor associative centers related to the premotor process. The standard neurological explanation is that the perceived will reported by the speaking left hemisphere does not correspond to the actions performed by the non-speaking right hemisphere, suggesting that these hemispheres may have independent volition. Similarly, one of the most significant symptoms of schizophrenia is the delusion of being controlled by an external force. Schizophrenics sometimes report that, despite acting in the world, they do not initiate or desire certain actions they undertake. This is sometimes likened to being controlled by someone else. Although the neural mechanisms underlying schizophrenia are not yet clear, there is an influential hypothesis that a failure of brain systems involved in comparing motor commands and feedback from the body (proprioception) leads to the associated hallucinations and control illusions. The question of free will is so complex that it cannot be definitively answered whether we possess it. In certain states, it may be severely disrupted, yet the Libet experiment unequivocally highlights that even if free will exists, it is an illusion, and we are merely observing our pre-defined actions.