Free Will - to have or not to have?

The question of whether humans possess free will, or are bound by determinism has long been a subject of debate across various fields, from philosophy to neuroscience. With the evolution of our understanding of brain function and decision-making processes, this debate has entered a new realm, one that examines the interplay between deterministic neural mechanisms and the potential for conscious choice. As our knowledge of the brain's intricate workings deepens, it becomes evident that decision-making in the mammalian brain is a complex blend of unconscious regulation, cognitive biases, and, perhaps, elements of free will.

The Deterministic Viewpoint: Predictable Components in a Predictable System

At the core of the deterministic argument is the idea that every component of the universe, including the human brain, is governed by predictable laws of science and mathematics. From this perspective, every decision is the result of a complex interplay of prior influences, experiences, neural structures, and the current state of the brain. This view, strongly supported by neuroscientists like Robert Sapolsky, posits that if we could know every detail about these factors, we could theoretically predict every decision a person might make. This deterministic stance suggests that decision-making is nothing more than a mechanical process, devoid of true free will.

Sapolsky in his new book, extrapolates this idea further, suggesting that when faced with a decision, the brain's response is pre-empted by a series of neurological processes that occur before one is even conscious of making a choice. This aligns with the findings from classic experiments by Benjamin Libet, which demonstrated that neural activity necessary for an action begins before the conscious intention to act. These findings imply that the sensation of making a choice is an illusion; the brain has already set the decision in motion before conscious awareness catches up.

The Complexity Argument: Beyond Mere Determinism

However, the deterministic perspective does not go unchallenged. Critics argue that viewing the brain merely as a predictable, deterministic machine overlooks the complexity inherent in biological systems. While every component within the brain may follow deterministic laws, the interactions between these components can give rise to unexpected, emergent behaviors that cannot be fully predicted or reduced to simple equations.

This complexity is highlighted by the concept of the "homeostatic risk thermostat," a theoretical construct suggesting that individuals maintain a preferred level of risk through an internal regulatory mechanism. This mechanism operates unconsciously, adjusting behavior to balance perceived risks and rewards. This risk thermostat is influenced by neurotransmitters such as dopamine, serotonin, and norepinephrine, which modulate responses to environmental stimuli, thereby adding layers of complexity to decision-making processes that go beyond simple cause-and-effect relationships.

Moreover, complexity science offers a different lens through which to view decision-making. Unlike deterministic systems that are fully predictable given sufficient information, complex systems are characterized by interactions and feedback loops that can lead to unpredictable outcomes. The brain, as a complex adaptive system, processes vast amounts of information, constantly updating its internal model of the world based on new experiences and sensory input. This aligns more closely with a probabilistic, Bayesian framework for decision-making, where the brain continuously refines its predictions and adjusts its behavior based on probabilities rather than certainties.

Bayesian Decision-Making: A Probabilistic Approach

The Bayesian model of decision-making provides an alternative to strict determinism by suggesting that the brain operates as a predictor-corrector mechanism. This model posits that the brain constantly makes predictions about the world based on past experiences and updates these predictions as new information becomes available. This process involves both fast, unconscious decision-making (akin to Kahneman's System 1) and slower, deliberate reasoning (System 2).

Under this framework, decision-making is not about calculating deterministic outcomes but about weighing probabilities and making the best guess based on available data. This probabilistic approach allows for flexibility and adaptability, recognizing that while certain outcomes may be more likely, there is always an element of uncertainty. This aligns with evidence from cognitive psychology and neuroscience, which shows that humans are capable of adjusting their beliefs and decisions in light of new evidence, even if unconsciously.

Cognitive Biases and the Role of the Prefrontal Cortex

Despite this flexibility, both unconscious and conscious decision-making are subject to cognitive biases. These biases are systematic deviations from rational judgment, influenced by heuristics, emotions, and past experiences. For instance, the prefrontal cortex, which is involved in higher-order functions like reasoning and self-control, is also shaped by societal norms, ethical frameworks, and personal experiences. These influences can lead to biases in decision-making, even in processes that are slow and deliberate.

Kahneman’s dual-process theory illustrates this well: System 1, responsible for fast, automatic decisions, is prone to biases because it relies on heuristics and past experiences to make quick judgments. In contrast, System 2, which governs slow, analytical thinking, is less susceptible to bias but still influenced by underlying unconscious processes, including the homeostatic risk thermostat.

Free Will and the Illusion of Control

The deterministic model challenges the traditional notion of free will. If our decisions are influenced by unconscious neural mechanisms, cognitive biases, and probabilistic predictions, is there any room left for free will? Some neuroscientists and philosophers argue that the sense of free will is just that—a sense, a perception constructed by the brain that can be easily disrupted under certain conditions, such as brain damage or neurological disorders.

However, others, like Tom Stafford, argue that this view is too simplistic and overlooks the complexity of human cognition. Stafford suggests that while our decisions are undoubtedly influenced by a myriad of factors, this does not negate the existence of free will. Instead, he proposes a more nuanced understanding: humans are complex biological machines capable of meaningful choice within the constraints of their biology. This perspective maintains that while our decisions are influenced by deterministic processes, the emergent properties of complex systems like the brain allow for a form of constrained agency that could be viewed as free will.

Conclusion: Navigating Between Determinism and Free Will

The debate over free will and determinism in decision-making is far from settled. On one hand, deterministic views rooted in neuroscience suggest that our choices are pre-determined by prior neural activity and external influences. On the other hand, the complexity and adaptability of the brain point towards a model of decision-making that allows for some degree of flexibility and unpredictability, consistent with a probabilistic, Bayesian framework.

Ultimately, the truth may lie somewhere in between. While we may not possess absolute free will in the traditional sense, our decisions are not entirely predetermined either. The interplay between deterministic neural mechanisms and the brain's capacity for complex, adaptive behavior suggests that we have a constrained form of agency—one that is influenced by, but not entirely bound by, the laws of determinism. As our understanding of the brain continues to evolve, so too will our understanding of what it means to choose, to decide, and perhaps, to be free.

References

• Sapolsky, R.M (2024). Determined: The Science of Life Without Free Will, Penguin, Random House, UK.
• Kahneman, D. (2011). Thinking, Fast and Slow. New York: Farrar, Straus and Giroux.
• LeDoux, J. E. (1996). The Emotional Brain: The Mysterious Underpinnings of Emotional Life. New York: Simon & Schuster.
• Panksepp, J. (1998). Affective Neuroscience: The Foundations of Human and Animal Emotions. New York: Oxford University Press.
• Stafford, T. (2019). It's not an illusion, you have free will. It's just not what you think, Mind April 2019.
• Sapolsky, R. M. (2004). Why Zebras Don't Get Ulcers: The Acclaimed Guide to Stress, Stress-Related Diseases, and Coping. New York: Henry Holt and Company.