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For centuries, the nature of consciousness has baffled scientists and philosophers alike. The question of what transforms neural activity into the rich, subjective experience of seeing a face, hearing a melody, or feeling the warmth of the sun has not been resolved. Despite decades of research, competing theories have remained largely isolated from each other, which has stalled progress towards a unified understanding of consciousness.
The Cogitate Consortium, a group of researchers from across the globe, including Professor Ole Jensen, Chair of Translation Cognitive Neuroscience from the University of Oxford, set out to change that. The consortium brought together the proponents of two influential theories of consciousness—Global Neuronal Workspace Theory (GNWT), led by Stanislas Dehaene, and Integrated Information Theory (IIT), proposed by Giulio Tononi—for a rigorous empirical test. Their findings have been published in the journal Nature.
Their adversarial collaboration, a model of scientific inquiry famously advocated for by Nobel laureate Daniel Kahneman over 20 years ago, represents a different way of doing science, with scientists having to accept their life’s work may not withstand scrutiny. Rather than seeking to confirm pre-existing beliefs, the experiment was designed so that all predictions, methods, and interpretations were registered in advance, eliminating post-hoc rationalisations, that is attempting to explain or justify the findings afterwards.
Under the guidance of a neutral team of investigators, the Cogitate Consortium designed an ambitious study with more than 250 participants, using a whole set of cutting-edge neuroimaging techniques: functional MRI (fMRI), magnetoencephalography (MEG), and intracranial EEG recordings from epilepsy patients.
The results may not have been quite what the proponents of the theories might have hoped for.
One of IIT’s key predictions failed: the expectation was that there would be sustained synchronisation between several visual areas in the brain. Synchronisation happens when different brain regions coordinate activity of the neurons within those regions over an extended period of time. The IIT theory expects synchronisation between early visual areas (those areas in the brain that deal with colour and shape processing) and mid-level visual areas (those regions of the brain that integrate the basic building block into more complex patterns). However, the synchronisation does not actually occur, which challenges the prediction of IIT.
Equally, GNWT faced challenges. While the prefrontal cortex was activated in response to some aspect of conscious, such as what general category an object belongs to, it was not active to other details people consciously noticed, such as the direction an object faced, or what their specific identity was. In addition, GNWT expects a burst – an “ignition” – of activity when the stimulus disappeared. However, this was not observed in the brain activity, thus challenging the theory’s premise that this ignition is necessary for maintaining conscious awareness.
Corresponding author Lucia Melloni, from the Max Planck Institute for Empirical Aesthetics (MPIEA), sees a deeper lesson in the results: “Real science isn’t about proving you’re right—it’s about getting it right. True progress comes from making theories vulnerable to falsification, not protecting them. This wasn’t about picking a winner; it was about raising the bar for how we test ideas”.
The neuroimaging research crucially incorporated MEG recordings, a technique capable of capturing neuronal activity throughout the entire brain. The MEG recordings were conducted by Professor Ole Jensen at the University of Oxford in collaboration with Huan Luo at Peking University.
Professor Jensen, who works across Oxford’s Departments of Psychiatry and Experimental Psychology, said:
This adversarial collaboration has not only provided crucial understanding of how consciousness emerges in the brain but has also revealed a novel and powerful methodology for conducting science, one that we will undoubtedly incorporate into our future MEG investigations on cognitive and clinical neuroscience. The consortium's work also clearly demonstrates the achievements possible through international collaboration, bringing together the foremost experts worldwide."