Uri Maoz had a passion for conducting human research during his PhD studies. His focus was on a niche area of computational neuroscience: investigating how the brain signals our arms to move and how this motion is perceived by our gray matter.
When his professor requested him to give a lecture for undergraduates, Maoz expected explicit guidance or at least some PowerPoint slides. But to his surprise, he was given complete freedom to educate on any topic as long as it was pertinent to the students. “I could have explored human brain enhancement,” he mentions. “Cyborgs or anything like that.”
However, that intriguing and somewhat sci-fi theme wasn’t what came to him spontaneously. His idea, which he recalls with enthusiasm: “What can neuroscience reveal about the nature of free will?”
The question of how—or even if—people make decisions (like what topic to cover in an undergrad lecture) had been on his mind since he read an article in his twenties proposing that … perhaps they don’t. This inquiry might lead to further ones: Had he truly chosen to read that article? How could he know if he was genuinely responsible for his life choices or merely experiencing an illusion of control?
“From that point, there was no going back,” states Maoz, now a professor at Chapman University in California. He completed his PhD in human movement, but afterward he delved deeper into the neural processes behind how desires and beliefs translate into actions—from lifting an arm to deciding whom to invite for dinner on a Friday night.
Today, Maoz plays a key role in the effort to (in a sense) elucidate the workings of that neural chain. His research has challenged and reinterpreted foundational neuroscience studies, bridging the gap between empirical science and philosophical discussions regarding free will. Above all, he has managed to expose new facets of the ongoing debate.
Machines and magic tricks
The notion of free will appears simple, yet it lacks a universally agreed-upon definition. One common perspective is that it represents the capability to make our own decisions and act purposefully—that we are in charge of our lives. However, physicists might pose questions about whether the universe operates in a deterministic manner and if human choices can occur within such a framework.
That’s a matter for physicists, according to Maoz. What neuroscientists can achieve is to explore what happens in the brain when individuals make decisions. “And that’s our goal: to comprehend how our wishes, desires, beliefs translate into actions,” he explains.
By the time Maoz completed his PhD in 2008, research into this question had been underway for decades. A pivotal study from the 1960s indicated that a hand movement—something one seems to intentionally decide—was preceded by the emergence of an electrical signal in the brain known as the “readiness potential.”
Building on that finding, in the 1980s, neuroscientist Benjamin Libet conducted the experiment that initially sparked Maoz’s interest in the topic—widely viewed until recently as a significant challenge to the idea of free will.
An electrical impulse in our brains can illuminate only so much about whether we are truly the creators of our own destinies.
“He simply had people sit still, and whenever they felt inclined, they would go like this,” Maoz says, mimicking wrist movements. Libet would then inquire where a moving dot appeared on a screen at the moment they first felt the impulse to flick. He discovered that the readiness potential not only emerged before they moved their hand but also before they reported feeling the urge to move—or, as interpreted by Libet, before they were aware they were going to move.
Subsequent studies have reaffirmed this observation, showing that the readiness potential shows up a second or two—and potentially, as fMRI suggests, up to 10 seconds—before participants claim to have made a conscious decision. “It implies we are basically passengers in a self-driving vehicle,” remarks Maoz. “The unconscious biological mechanism does all the navigating, while our conscious mind sits in the driver’s seat and takes the credit.”
Maoz originally approached his own investigations with variations of Libet’s methodology. He collaborated with epilepsy patients who had electrodes implanted in their brains for medical reasons and could forecast which hand they would lift before they did.
However, some of the studies inspired by Libet troubled him. “All these outcomes pertained to wholly arbitrary choices. Raise your hand whenever you feel like it,” he states. “Why? There’s no reason.” Such a decision differs significantly from, for instance, opting to end a romantic relationship. Imagine telling someone they weren’t in charge of that decision.
The field was neglecting significant choices, he argues—those that genuinely shape individual lives.
Maoz began inviting philosophers to refine his approach. They would challenge him to grapple with the differences in meaning among concepts such as intention, desire, and urge. While neuroscientists have often grouped these ideas together, philosophers dissect them: Desire is a longing that may not lead to action; urge denotes immediacy and compulsion; and intention encompasses committing to a plan. (Maoz has concentrated on intention specifically—including, recently, the potential intentions of AI.)
In 2017, he facilitated his inaugural free-will conference, gathering many philosophers interested in autonomy. “Thank you all for coming,” he recalls stating at the meeting’s commencement. “As if you had a choice.” One day, the group took a trip on a lake. While they enjoyed shrimp, someone quipped their fear that the boat might sink, resulting in the demise of everyone in the field.
The remark didn’t induce existential dread in Maoz. Rather, he thought that since the entire field was present, why not rally them to apply for a research grant? “He simply envisions what the next step should be, and possesses an exceptional capability to make it a reality,” notes Liad Mudrik, a neuroscientist at Tel Aviv University and a regular collaborator.
This capability is rare among scientists, asserts Chapman colleague Aaron Schurger, with whom Maoz co-directs the Laboratory for Understanding Consciousness, Intentions, and Decision-Making (LUCID, fittingly). “I genuinely believe that Uri is kind of at the confluence of this field right now because he’s exceptionally skilled at uniting people around these significant ideas,” he states.
Donations and interruptions
Maoz has recently advanced one of the major concepts that have consistently captured his attention: the varying dynamics of trivial versus important decisions in the brain. In collaboration with Mudrik, he has analyzed the neural differences between selections and choices—terms they use to differentiate random decisions and those that impact your life and evoke emotions.
Readiness potential? Their analyses didn’t detect it prior to the choices. In 2019, Maoz and his team published a paper measuring electrical activity in individuals’ brains as they pressed a key to select one of two nonprofits to which to donate $1,000—indeed, actual funds. They compared this activity with instances when the same group randomly pressed a key to donate $500 each to two nonprofits. The team observed readiness potential for the arbitrary choice, but not for the $1,000 decision.
They concluded that Libet’s findings do not pertain to significant decisions, implying that readiness potential may not truly indicate that one’s brain makes a choice before one is aware of it. “Had Libet chosen to focus on deliberate decisions, perhaps the entire discussion regarding neuroscience disproving free will as an illusion would have been averted,” Mudrik suggests.
Maoz’s work has inspired others to reevaluate Libet’s findings. “It has greatly enriched my thinking,” remarks Bianca Ivanof, a psychologist whose dissertation examined Libet’s approaches. They discover that readiness potential is identified at different intervals based on how the rotating-dot experiment is structured, complicating the ability to compare and interpret outcomes.
Maoz has also continued to gather data on the subject. For instance, last year, he utilized an EEG to monitor electrical signals in individuals’ brains as they prepared to press a space bar on a keyboard. At random intervals, he interrupted their preparation with an audible tone and inquired about their intentions. He found no correlation between readiness potential and whether they intended to press the key—evidence suggesting that the potential does not indicate the buildup of either conscious or unconscious plans. However, the team did identify a signal in another brain region when participants reported they were preparing to move.
So … that’s free will? Regrettably, Maoz would likely respond Well, not exactly. An electrical impulse in our brains can reveal only a limited amount regarding whether we are indeed the designers of our own fates. Perhaps the ambiguous data from neurons is precisely the issue. “I don’t believe it can be reduced to a yes-or-no question,” Maoz asserts. It’s conceivable that our less significant choices aren’t made mindfully while the more substantial ones are; we may possess the conscious ability to alter an intended action, but only under certain brain states.
Neuroscientists probably cannot ascertain, independently, if free will truly exists. Yet they can, according to Maoz, analyze how semantically distinct decision-making elements—desires, urges, intentions, wishes, beliefs—manifest within our brains and transform into actions. “That’s something we are indeed making strides on,” he states, “and I believe that will aid in understanding what we do control.” It may also help us reconcile with what we cannot.
Sarah Scoles is a freelance science journalist and author based in southern Colorado.
