A professor proposes that behavior emerges through continuous interactions among sensory, sensorimotor, and motor processes rather than a dedicated decision-making mechanism.
There may be a gap between how people believe decisions are made and what actually happens inside the brain, according to Indiana University professor Tom James.
For decades, both scientific theories and everyday thinking have treated decision-making as a separate step between perception and action. Under this traditional view, information moves through a linear sequence from sensing to thinking to acting, with each stage linked to a distinct brain function.
Many research methods, especially those used in model-based cognitive neuroscience, are built around this idea and reinforce it. It also matches our everyday experience. As James puts it, “Our actions feel like they are caused by decisions based on desires, beliefs, and intentions.”
However, James argues that this linear framework, often called the “sandwich model,” does not fit what scientists know about the brain. While researchers have identified neural systems for sensing and movement, there is no comparable brain mechanism that clearly serves as a dedicated decision-making stage.
From Decision-Making to Action Selection
Instead of proposing a separate decision-making center that directs behavior, James argues that actions emerge from the combined activity of sensory, sensorimotor, and motor processes. He prefers the term “action selection,” which reflects an ongoing interaction among the brain, body, and environment rather than a simple step-by-step process. He says this view also requires research methods that can better capture these dynamic interactions.
That does not mean decisions are unreal.
As James explains, “Of course they do. We use this language all the time, and it’s very helpful in terms of describing behavior. The leap, I think, is to say that the brain works by having decision-making or control processes. It produces behavior that is well described in that way. But it doesn’t need a process that does that to make it look that way.”
James, a professor in Indiana University’s Department of Psychological and Brain Sciences, presents these ideas ina study published in the Journal of Cognitive Neuroscience.
Why Decisions May Be Abstract Concepts
To support his argument, James draws on a “physicalist” framework associated with philosophers such as Daniel Dennett. Under this view, only physical processes, including sensory and motor activity, can directly cause physical events. Because decisions are nonphysical concepts, they cannot themselves produce actions or other physical effects.
To illustrate the idea, James offers several analogies.
One compares decisions to Dennett’s description of the self as a center of mass (CoM) or center of gravity. A center of mass is a mathematical concept rather than a physical object. You cannot move an object’s center of mass without moving the object itself. James argues that decisions are similarly abstract and cannot directly influence the physical world.
How Everyday Concepts Can Mislead Science
James also points to the difference between everyday language and detailed scientific explanations. For example, people often say “the university” when describing what happens within an institution. The phrase is a convenient shorthand for the people, buildings, and organizations that make up the university.
Likewise, saying “the university took certain actions during a campus protest” does not explain what actually happened. It leaves out the meetings, phone calls, and individual decisions that produced those actions.
James argues that the same problem applies to decisions. “As mental phenomena, they are defined on too abstract a level for the goals of cognitive neuroscience.” In other words, they do not reveal the specific brain activity responsible for behavior.
What a Simple Robot Reveals About Human Behavior
James extends the argument with an example from robotics.
He describes a robot built with only simple sensory, motor, and sensorimotor components. Even without any ability to make decisions or develop strategies, the robot displays “wall-following” behavior that appears purposeful and goal-directed.
“The robot does not have decisions built into it,” James explains. “It just senses its environment and moves around accordingly. And based on the environment, wall-following turns out to be a good thing. It looks intentional. It looks strategic. It looks like the robot is making decisions. And yet, it is not. The reason we know it is not is that there are no systems built into it to do that.”
Challenging the Central Controller Theory
If a robot without decision-making abilities can still appear to make decisions, James argues it is reasonable to ask whether humans might create the same impression. He believes this explanation is more parsimonious than one based on what he calls “a higher-level, central controller that monitors and regulates sensory and motor processes.”
James also argues that the idea of a central controller creates a philosophical problem that dates back to Descartes.
“Explaining that the brain works by way of a central controller suggests that you haven’t figured out how the brain works, because you’ve just put a person inside your brain,” says James. “Dennett called this idea the Cartesian Theatre. That person inside your brain would need another person inside its brain, which would need a person inside its brain, and so on, in an infinite regress. So the problem is never solved. It’s just passed on.”
The Future of Decision-Making Research
James concludes that testing this alternative view will require new experimental approaches capable of capturing the complex, ongoing interactions among the brain, body, and environment that give rise to what people describe as decision-making.
His own lab has already begun exploring these questions using theories of embodied cognition and ecological psychology. James believes this approach could help cognitive neuroscience better understand not only how behavior emerges but also many other mental and cognitive processes.
Reference: “Sensorimotor Mechanisms of Decisions and Actions” by Thomas W. James, 1 June 2026, Journal of Cognitive Neuroscience.
DOI:10.1162/JOCN.a.2484
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