- The largest consciousness study ever found neither leading theory was correct.
- Neither IIT's posterior synchronization nor GNWT's prefrontal ignition appeared in the data.
- Conscious perception linked most strongly to posterior sensory brain regions.
Can theories of consciousness explain how our sense of being arises? Perhaps, but it's not straightforward.
Christof Koch has now lost the same bet twice.
In 1998, the neuroscientist wagered philosopher David Chalmers that science would identify the "neural correlates of consciousness" within 25 years. In June 2023, Koch conceded and paid with a case of fine Portuguese wine. Then he doubled down, extending the wager to 2048.
The results that cost Koch his bet came from a seven-year experiment he helped design. The Cogitate Consortium, spanning 12 laboratories and 256 participants, set out to settle which of two dominant theories better explains how brains generate conscious experience.
Neither theory won.
Key figure
256
participants across 12 labs in the largest adversarial study ever conducted into theories of consciousness.
The Theories That Were Tested
Two frameworks have dominated consciousness research for decades.
Integrated Information Theory (IIT), developed by Giulio Tononi at the University of Wisconsin, proposes that consciousness emerges from interconnected brain regions sharing information in specific patterns. The more integrated the information, the richer the experience.
Global Neuronal Workspace Theory (GNWT), championed by Stanislas Dehaene at the Collège de France, argues that consciousness arises when information reaches a threshold and broadcasts across the brain's prefrontal cortex like an announcement over a loudspeaker.
What are the other theories of consciousness?
Beyond the two tested here, over twenty theories compete to explain awareness. Higher-Order Theories propose consciousness requires the brain to monitor its own mental states. Recurrent Processing Theory focuses on feedback loops within sensory areas. Predictive Processing suggests consciousness emerges when the brain's expectations clash with reality.
Both theories make specific predictions about what brain activity should look like during conscious perception.
What the Data Actually Showed
The Cogitate team designed experiments where both theories predicted different outcomes. Participants viewed images while researchers recorded brain activity using EEG, fMRI, and intracranial electrodes.
IIT predicted synchronization between posterior brain regions. It didn't appear.
GNWT predicted a sudden "ignition" in the prefrontal cortex when participants became conscious of a stimulus. That ignition was absent.
The prefrontal cortex did decode what category of image participants saw. It could not decode the specific orientation, as GNWT predicted.
"The theories are just too different in their assumptions and explanatory goals, and the available experimental methods too coarse, to enable one theory to conclusively win out over another," said Anil Seth, a professor of cognitive and computational neuroscience at the University of Sussex.
The result validates concerns raised in a 2023 letter signed by over 100 researchers questioning whether IIT in particular was falsifiable. The Cogitate data suggests it may be more falsifiable than critics thought, just not in the way its proponents hoped.
Consciousness May Be Closer to Sensation Than Thought
One finding did emerge consistently. Conscious perception correlated most strongly with activity in posterior sensory regions of the brain, not the prefrontal areas that GNWT emphasizes.
Koch himself distinguishes between intelligence and consciousness this way: intelligence is about doing, consciousness is about being. The Cogitate results hint that being may emerge from how the brain processes the world directly, not from how it thinks about that processing.
Theories of consciousness try to explain what causes consciousness, and how it emerges from how our brain work. (Science Reader)
The question itself is not new.
In 1643, Princess Elisabeth of Bohemia challenged Descartes to explain how an immaterial mind could move a physical body. Nearly four centuries later, 256 participants and three imaging modalities have confirmed the question remains open.
A 2024 study in the New England Journal of Medicine found that roughly one in four patients diagnosed as vegetative showed signs of hidden awareness when tested with specific methods. Understanding where consciousness arises could eventually help clinicians detect this covert consciousness.
Neither Theory Is Dead
More on consciousness
Scientists Can Now Rewrite Memories in Living Brains
Researchers have figured out how to implant false memories, delete real ones, and swap emotional responses between events - in mice.
→More than twenty theories of consciousness exist. Cogitate tested two.
Both camps are already revising their frameworks. Tononi's team argues the experiments tested peripheral predictions rather than IIT's core claims. Dehaene's supporters note that the study used relatively simple stimuli.
"True progress comes from making theories vulnerable to falsification, not protecting them," said Lucia Melloni, co-senior author from the Max Planck Institute for Empirical Aesthetics.
Koch remains undeterred. "Unravelling this mystery is the passion of my entire life," he told reporters. The new 2048 deadline gives him time to watch the theories evolve.
The bet continues.
Sources
- Primary Research: Cogitate Consortium (2025). "Adversarial testing of global neuronal workspace and integrated information theories of consciousness." Nature
- Additional Context:
- Landmark experiment sheds new light on the origins of consciousness (Allen Institute via EurekAlert)
- Rethinking Consciousness: When Science Puts Itself to the Test (Max Planck Institute for Empirical Aesthetics)
- Princess Elisabeth and Descartes (MIT Press Reader)
Fact Check: Claim-by-Claim Verification Verified
Limits and uncertainties
Core findings are clearly supported by the primary Nature paper and institutional releases from Allen Institute and Max Planck. Neither IIT nor GNWT won outright, validating adversarial testing but leaving field open with 20+ theories. Results rely on specific visual stimuli; revisions ongoing by Tononi and Dehaene teams. Claims like Koch's bets add narrative but are accurately reported. Readers should note methods tested predictions, not full theories, advancing science without hype.
Bottom line
The article accurately reports the Cogitate study's challenge to IIT and GNWT, highlighting posterior brain activity in consciousness. This rigorous test pushes neuroscience forward without overclaiming victory for any side. Progress continues with open data and new collaborations.
Fact-checked by Perplexity Sonar Pro on 2026-01-21
