Decision-Making: What If the Brain Took More Than One Route?

Our thoughts and decisions appear to follow a logical thread, a well-defined trajectory dictated by the brain’s stable organization. For decades, neuroscience has sought to map this organization, identifying specialized networks that activate depending on the task at hand. When we make a decision, whether by scanning a set of visual elements or analyzing a complex situation, we instinctively assume that our brain follows a single strategy, engaging the same neural circuits each time. But what if this assumption is flawed? What if, instead of a predetermined pathway, our brain had multiple routes to reach the same conclusion?

This very question is at the heart of a recent study published in Nature Communications, which challenges the idea of a uniform neural activation for a given cognitive task. Led by Johan Nakuci and his colleagues, the research reveals that decision-making relies on multiple distinct brain configurations, some involving regions previously thought to be inactive during tasks requiring sustained attention. Among the most surprising discoveries is a particularly intriguing phenomenon: the involvement of the Default Mode Network (DMN), a brain network traditionally associated with daydreaming and spontaneous thought, in executing a perceptual task.

This finding disrupts our understanding of cognitive function and raises fundamental questions about neural flexibility. The brain does not merely execute tasks mechanically by activating a predetermined pattern; rather, it adapts its response, alternating between different pathways to reach the same result. This variability, long considered mere noise in neuroscience studies, could, in fact, be one of the cornerstones of human cognition.

One decision, many roads: The brain’s hidden flexibility

Our understanding of the brain has been built on the premise that each cognitive task activates a specific network of brain areas, forming a sort of “neural signature.” This model has been largely supported by functional brain imaging (fMRI), which visualizes blood oxygenation changes in different brain regions. However, by closely examining neural activations related to perceptual decision-making tasks, researchers discovered that the brain does not rely on a single route but instead employs multiple distinct configurations to accomplish the same task.

Far from being an anomaly, this diversity in activation can be explained by the concept of functional degeneracy, a principle suggesting that different brain structures can perform the same function. Until now, this theory has primarily been used to understand the brain’s adaptability following injury. However, this study demonstrates that even in healthy individuals, various neural circuits can be engaged to produce the same cognitive response.

The study conducted by Nakuci and his team involved three separate experiments focusing on perceptual discrimination tasks. In the first experiment, fifty participants were asked to identify the dominant color in a cloud of dots. The second and third experiments required participants to make decisions about the motion of stimuli. Throughout each trial, fMRI recorded brain activations to examine the neural patterns underlying decision-making.

Rather than relying solely on conventional data analysis, the researchers took an innovative approach by applying an advanced classification method known as modularity-maximization clustering. This technique identifies distinct subgroups of brain activations at the level of individual trials. Their findings revealed that for the same task, brain activity did not follow a single model but clustered into three distinct patterns in the first two experiments and two in the third.

The hidden player: how the default mode network shapes decisions

The most surprising discovery involved one of these activation subgroups, a specific pattern in which the Default Mode Network (DMN) was heavily recruited. This network, typically associated with introspection, spontaneous thought, and mind-wandering, has traditionally been considered “deactivated” during tasks requiring focused attention. Yet, the results show that a particular subtype of perceptual decision-making is precisely driven by its activation.

Why would a network associated with introspection be involved in something as precise as a visual decision? The researchers suggest that this activation pattern reflects an alternative cognitive strategy, one in which certain decisions rely more on a global, intuitive evaluation of the stimulus rather than a detailed, methodical analysis. This phenomenon is reminiscent of how an experienced musician instinctively plays a melody without consciously breaking down each note.

Flexibility over rigidity: a new perspective on cognition

These findings challenge the classical dichotomy between attentional networks and introspective networks. Rather than being rigid, the brain’s architecture appears to be far more dynamic than previously thought. This research could have major implications, particularly in understanding individual differences in decision-making. Do some people naturally favor an intuitive approach while others lean toward more analytical reasoning?

The results also suggest that brain flexibility could play a crucial role in complex decision-making contexts, such as medical diagnosis, crisis management, or even driving. If different neural strategies coexist, understanding the factors that influence their activation could help us better tailor our choices to different situations.

This study sheds light on an overlooked facet of the brain: its ability to mobilize multiple distinct strategies to reach the same outcome. Long dismissed as mere experimental variability, this diversity in activation may actually reflect a fundamental principle of brain function.

With advances in technology and artificial intelligence, it may one day be possible to predict which brain configuration will be favored in a given context. These prospects open up fascinating avenues for research on how our brain selects its cognitive strategies and the factors that shape these choices.

The brain’s infinite possibilities

Far from being a machine with fixed patterns, the human brain exhibits an unexpected flexibility, capable of reorganizing its activity based on circumstances. This study brilliantly illustrates the complexity and adaptability of our neural networks, highlighting a fundamental phenomenon: there is no single way to accomplish a cognitive task, only multiple paths leading to the same destination.

Every decision we make is the result of a delicate balance between different cerebral strategies, an interplay between analysis and intuition, between logic and perceptual fluidity. This intricate web of neural activations is more than just a scientific curiosity; it holds the key to understanding our own cognitive processes and the profound richness of human thought.

Reference

Nakuci, J., Yeon, J., Haddara, N., Kim, J.-H., Kim, S.-P., & Rahnev, D. (2025). Multiple brain activation patterns for the same perceptual decision-making task. Nature Communications, 16, 1785.