5-Min Science: Researchers Test Competing Consciousness Theories
- BioSource Faculty
- May 20
- 6 min read
Updated: Aug 1

Introduction
In the Scientific American article, "Where Does Consciousness Come From? Two Neuroscience Theories Go Head-to-Head," Allison Parshall (2025) reports on the landmark Cogitate Consortium study comparing two dominant theories of consciousness: Global Neuronal Workspace Theory (GNWT) and Integrated Information Theory (IIT).
The Scientific American article explores how this adversarial collaboration sought to directly test competing models using brain imaging. Complementing this, Carl Zimmer’s New York Times coverage (2025) broadens the context by showing that GNWT and IIT are only two among at least 29 identified theories of consciousness, including Adaptive Resonance Theory, Dynamic Core Theory, and First Order Representational Theory, illustrating the field’s theoretical fragmentation.
The Challenge of Studying Consciousness
Parshall emphasizes the inherent scientific difficulty of studying consciousness, which is not directly observable. Techniques like intracranial electroencephalography (EEG), which records brain activity from inside the skull, provide neural data but no access to subjective experience. Robert Chis-Ciure of the University of Sussex explains that while behaviors and brain states can be measured, the private nature of awareness itself makes empirical investigation uniquely challenging.
The Competing Theories
Parshall and Zimmer outline GNWT and IIT’s distinct approaches. GNWT, developed by Stanislas Dehaene, views consciousness as arising when prefrontal regions globally broadcast sensory information, akin to spotlighting stimuli on a cognitive “stage.” IIT, developed by Giulio Tononi, defines consciousness in terms of informational complexity and integration, asking what kind of physical system (brain or otherwise) could generate a unified, coherent experience. Both theories produce testable neural predictions, which the Cogitate Consortium aimed to evaluate.
The Cogitate Consortium Study
Zimmer details how Lucia Melloni and 41 other scientists launched the Cogitate Consortium in 2018 to overcome the usual pattern of scientists only defending their own models. They implemented adversarial collaboration, where rival camps work with neutral researchers to design shared experiments. Eight labs across the U.S., Europe, and China tested 267 participants using three brain-imaging methods: intracranial electrodes (in epilepsy patients), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG). Tasks included video games requiring conscious perception, such as catching colored disks or identifying blurred faces.
Findings That Challenge Both Theories
Published in Nature, the Cogitate results challenged both GNWT and IIT. GNWT’s predicted prefrontal “ignition” signal when stimuli disappeared was largely absent; IIT’s predicted posterior network synchrony was also unsupported. All three imaging modalities converged: both theories provided partial but incomplete explanations. Oscar Ferrante of the University of Birmingham summarized this bluntly to Zimmer: “both theories are incomplete,” reinforcing that neither framework yet captures the full neural basis of conscious experience.
Peer Review Conflicts and Criticism
Zimmer reports that Hakwan Lau (Sungkyunkwan University), a consciousness theorist and formal reviewer, criticized the Cogitate paper for insufficiently specifying where in the brain predictions would be tested. Lau publicly posted his critique and co-authored an open letter signed by 124 scientists under the name “IIT-Concerned,” which labeled IIT pseudoscience due to its lack of falsifiability and its expansive claims, including the possibility that plants or computer chips could possess minimal consciousness. This controversy intensified debates about IIT’s scientific legitimacy.
Philosophical Stakes and Scientific Disputes
Parshall and Zimmer both note the broader philosophical tensions. While critics accuse IIT of overreaching into metaphysical claims like panpsychism—the idea that consciousness pervades all matter—Tononi’s team defended the theory in Nature Neuroscience, accusing critics of zeal without sufficient empirical counterarguments. Anil Seth, quoted by both authors, emphasizes that adversarial collaborations like Cogitate can clarify weaknesses in current models even if they do not decisively settle theoretical disputes, gradually moving the field toward sharper, more testable hypotheses.
The Broader Landscape of Consciousness Research
Zimmer expands the discussion by noting that a 2021 survey identified at least 29 distinct theories of consciousness. This underscores that, far from converging, the field remains theoretically splintered. Joel Snyder (University of Nevada) expressed skepticism to Zimmer that the Cogitate study had narrowed this theoretical sprawl, and Lau argued that the study’s findings had not meaningfully shifted the landscape. Instead, the field faces the ongoing challenge of refining and pruning competing models.
Practical Importance Beyond Theory
Parshall highlights the clinical relevance of consciousness research, particularly in assessing awareness in coma, brain injury, and anesthesia patients, where critical decisions about life support hinge on determining conscious presence. Chis-Ciure underscores the ethical stakes, warning that avoiding the hard problem of consciousness risks life-or-death consequences for vulnerable patients.
Conclusion
Together, Allison Parshall’s Scientific American reporting and Carl Zimmer’s New York Times coverage offer a rich, multifaceted view of consciousness research today. While the Cogitate Consortium’s unprecedented adversarial collaboration revealed the incompleteness of both GNWT and IIT, it also exemplified a more rigorous, cooperative scientific approach. Yet the field remains divided, with dozens of competing theories and active public disputes. Despite theoretical impasses, pursuing a scientifically grounded understanding of consciousness continues, driven by intellectual curiosity and urgent clinical need.
Key Takeaways
The Cogitate Consortium’s large-scale adversarial collaboration tested two major theories of consciousness—GNWT and IIT—but found that neither offered a complete explanation, revealing critical gaps in both frameworks.
Beyond GNWT and IIT, at least 29 distinct theories of consciousness exist, highlighting the theoretical fragmentation and lack of convergence in the field, as emphasized in Zimmer’s reporting.
The Cogitate study used an unprecedented combination of intracranial EEG, fMRI, and MEG across 267 participants, applying rigorous experimental designs to assess conscious perception during visual tasks.
The study’s publication sparked major controversy, including a public critique by Hakwan Lau and 124 scientists labeling IIT pseudoscience, reflecting deep philosophical and empirical tensions over how consciousness theories should be tested.
Despite theoretical disputes, consciousness research has immediate ethical and clinical importance, guiding decisions in cases like coma, anesthesia, and severe brain injury, where assessing residual awareness has life-or-death implications.
Glossary
adversarial collaboration: a research approach where rival scientific camps work together with neutral investigators to design experiments that fairly test their competing predictions.
adaptive resonance theory: one of several competing theories of consciousness, proposing that learning and perception arise from dynamic matching of neural patterns.
anesthesia: a medically induced state of unconsciousness or insensitivity, used during surgical or medical procedures.
brain-imaging techniques: methods such as fMRI, EEG, and MEG that allow researchers to visualize and measure brain activity noninvasively or invasively.
Carl Zimmer: a science journalist at The New York Times who reported on the Cogitate Consortium’s consciousness study and the broader theoretical landscape.
Christof Koch: a cognitive neuroscientist and prominent advocate of integrated information theory in consciousness research.
cognitive psychology: the branch of psychology studying mental processes like attention, perception, memory, and language.
Cogitate Consortium: a multi-lab, multi-country research collaboration launched in 2018 to directly test competing consciousness theories using adversarial methods.
coma: a state of prolonged deep unconsciousness typically caused by brain injury or medical conditions.
consciousness: the subjective experience of awareness, sensations, thoughts, and perceptions that define being awake and responsive.
dynamic core theory: a theory proposing that consciousness arises from rapidly integrated and differentiated neural processes within a central core of the brain.
electroencephalography (EEG): a method for recording electrical activity in the brain using scalp or intracranial electrodes.
falsifiability: a fundamental criterion for scientific validity, requiring that a theory’s claims can, in principle, be disproven by empirical evidence.
first order representational theory: a consciousness model suggesting that mental states are conscious because they represent external stimuli directly.
functional magnetic resonance imaging (fMRI): a brain imaging method that measures blood flow changes associated with neural activity.
Global Neuronal Workspace Theory (GNWT): a theory proposing that consciousness emerges when sensory information is globally broadcast across the brain, especially through frontal regions.
Hakwan Lau: a neuroscientist who publicly criticized the Cogitate study and co-authored the “IIT-Concerned” open letter challenging the scientific validity of IIT.
ignition: in GNWT, the process by which specific neural activation patterns reach global awareness, typically associated with frontal brain regions.
information theory: the mathematical study of information transmission, processing, and complexity, foundational to integrated information theory.
Integrated Information Theory (IIT): a theory positing that consciousness arises from the degree of integrated and differentiated information within a system, not tied to specific brain regions.
intracranial electrodes: devices inserted inside the skull to directly measure electrical brain signals, often used in clinical epilepsy treatment.
Lucia Melloni: a neuroscientist who co-led the Cogitate Consortium’s design and execution of the adversarial collaboration study.
magnetoencephalography (MEG): a brain imaging technique that records magnetic fields generated by neural electrical activity.
Oscar Ferrante: a neuroscientist at the University of Birmingham involved in the Cogitate Consortium, emphasizing the incompleteness of current consciousness theories.
panpsychism: the philosophical view that consciousness is a fundamental property pervading all matter, including nonliving systems.
posterior brain regions: brain areas toward the back of the head, including the parietal and occipital lobes, implicated in sensory integration and visual processing.
pseudoscience: claims or theories presented as scientific but lacking empirical testability, falsifiability, or adherence to scientific standards.
Stanlislas Dehaene: a cognitive neuroscientist and originator of global neuronal workspace theory.
subjective experience: the private, first-person perspective of awareness and feeling, central to the study of consciousness.
synchrony: the coordinated firing or activation of neural networks, predicted by IIT as a marker of integrated conscious processing.
visual perception tasks: experimental tasks designed to measure conscious awareness of visual stimuli, such as detecting blurred faces or catching moving disks.
Reference
Cogitate Consortium., Ferrante, O., Gorska-Klimowska, U. et al. (2025). Adversarial testing of global neuronal workspace and integrated information theories of consciousness. Nature. https://doi.org/10.1038/s41586-025-08888-1
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