Where Does Consciousness Live? A Landmark Study Challenges the Leading Theories
Determining precisely where consciousness originates within the brain continues to pose one of the most fascinating and challenging puzzles for neuroscientists. Unlike many phenomena explored by science, consciousness itself is fundamentally inaccessible through direct external observation. A groundbreaking new study offers fresh clues, challenging existing theories and opening avenues for new understanding.
Scientists attempting to understand consciousness have gravitated toward two predominant frameworks: Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT). Anil K. Seth, neuroscientist and professor of Cognitive and Computational Neuroscience at the University of Sussex., explained to Scientific American that these models are fundamentally distinct, built on different assumptions, and potentially define consciousness in divergent ways.
To rigorously test these competing theories against one another, researchers formed the Cogitate Consortium, a collaboration spanning 12 laboratories worldwide. The ambitious project’s purpose was straightforward yet daunting: evaluate each theory’s predictions through an extensive brain-imaging study.
A global team of neuroscientists examined brain activity in 256 individuals across laboratories in the United States, Europe, and China. While participants viewed images of faces and everyday objects, researchers carefully tracked their brains’ electrical and magnetic signals along with changes in blood flow to identify active areas.
The full results were recently published in the journal Nature and provided intriguing but inconclusive outcomes, sparking more questions than definitive answers.
GNWT imagines the brain as a theater. Most mental activity happens backstage—unconscious, behind the curtains. But when a stimulus is important enough, it’s “spotlighted” and pulled onto the main stage, where it becomes part of conscious awareness. This theory points to the frontal regions of the brain, such as the prefrontal cortex, as crucial hubs. It suggests consciousness emerges when information is broadcast widely across the brain, allowing different cognitive systems (like memory, vision, or language) to access and process it.
IIT, on the other hand, isn’t about spotlighting—it’s about webs of connection. This theory proposes that consciousness arises from how richly information is integrated across a system. The more interconnected and differentiated the brain’s activity is—especially in the posterior, sensory-heavy regions—the more vivid and complex the conscious experience. IIT even offers a mathematical measure for this integration, called phi (Φ), though critics argue it’s hard to test in real brains.
In the Cogitate Consortium’s experiment, participants engaged in tasks involving visually rotated faces and letters, requiring conscious perception. Utilizing three advanced imaging methods—functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and intracranial EEG—the study sought robust evidence supporting either theory
Ultimately, neither model received unequivocal support from the data. “The fact that you didn’t see that is something that I think is a significant challenge,” said Seth, who wasn’t involved in the new study. The frontal activity GNWT anticipated when stimuli vanished from consciousness was largely absent, while IIT’s expected posterior neural synchrony was similarly elusive.
“It was always understood that a single experiment [wasn’t] going to refute a specific theory,” Seth said, acknowledging the nuance in scientific exploration. “You’re probably not going to change the minds of the proponents of each theory, but it’s more allowing the community as a whole to sort of alter their consensus about what’s going on.”
Christof Koch, a cognitive scientist at the Allen Institute in Seattle and a co-author of the Cogitate study, acknowledged the complexity of these results.
“Where are the neuronal footprints of consciousness in the brain? Very crudely put, are they in the front of the cortex—the outermost layer of the brain—such as the prefrontal cortex, as predicted by the Global Neuronal Workspace Theory?” Koch asked, noting this area is critical for uniquely human cognitive functions like planning and social interactions. “Or are the footprints in the back regions of the cortex, the posterior cortex?” Koch continued. Koch has helped in developing later versions of the IIT.
“Here, the evidence is decidedly in favor of the posterior cortex. Either information pertaining to the conscious experience couldn’t be found in the front or it was far weaker than in the back. This supports the idea that while the frontal lobes are critical to intelligence, judgment, reasoning, etc., they are not critically involved in seeing, in conscious visual perception.”
However, the researchers did not observe enough sustained connections in the posterior cortex to fully support the Integrated Information Theory, indicating that neither theory comprehensively explains the mechanism behind consciousness.
In June 2023, The Cogitate Consortium provided a progress report on the experiment, acknowledging that there was no clear winner yet and pledging to continue the study. IIT faced significant scrutiny when over 100 scholars criticized it as “pseudoscience,” highlighting the theory’s abstract nature and perceived lack of falsifiability.
Later that year, this controversy became a flashpoint, reflecting deeper tensions within the neuroscience community about how consciousness theories should be formulated and empirically tested. Critics specifically expressed discomfort with IIT’s potential implications, such as its alignment with panpsychism—the philosophical idea that consciousness may exist even in nonliving entities. The argument came to a head in Nature Neuroscience last month.
This public confrontation has sparked important conversations about scientific rigor, the precision required in consciousness research, and how theories must become testable in practical, empirical terms. Seth views this moment as indicative of a discipline at a critical juncture:
“Everyone has their own theory. And that’s not a great state of affairs. So I think there’s this feeling that, indeed, the theories need to become a bit more precise.”
As Scientific American acknowledged, confrontations like this are not unprecedented in science. In 1919, Einstein’s general theory of relativity famously confronted Newtonian gravity during a solar eclipse, eventually emerging triumphant. Koch and other researchers see similar value in the current adversarial approach—an essential step forward in understanding how consciousness emerges from neural processes. By systematically confronting different models with robust experimental designs, the scientific community can gradually uncover deeper truths about consciousness.
This type of research promises far more than just theoretical clarity. A better understanding of consciousness could profoundly impact the treatment and diagnosis of patients with severe brain injuries or disorders of consciousness and even optimize the administration of general anesthesia.
“I observe your behavior. I observe your brain if I do an intracranial electroencephalography study. But I don’t ever observe your experience,” said Robert Chis-Ciure, a postdoctoral researcher studying consciousness at the University of Sussex in England.
“There are people that are taken away from life-support intervention because they are deemed as not being ‘there.’ The stakes are too high to not tackle the problem head-on.”
Moumita Basuroychowdhury is a Contributing Reporter at The National Digest. After earning an economics degree at Cornell University, she moved to NYC to pursue her MFA in creative writing. She enjoys reporting on science, business and culture news. You can reach her at moumita.b@thenationaldigest.com.