COGITATE Study: Landmark Experiment Tests Competing Theories of Consciousness — Neither Passes Unscathed

In one of the most ambitious experiments ever mounted in consciousness science, the COGITATE collaboration — a multi-laboratory international project — set out to test two of the leading theories of consciousness against one another. The result, published across a series of papers in 2024 and 2025, did not deliver a clear winner. Instead, it revealed that both theories, while capturing important aspects of conscious experience, fell short of a complete explanation — challenging the field to deepen its theoretical foundations.

The Adversarial Collaboration Protocol

COGITATE, short for Collaboration on the Comparison of Integrated and Global Theories of Experiential States, was designed as an adversarial collaboration — a research methodology in which proponents of competing theories agree on a set of experimental predictions in advance, then conduct neutral, third-party experiments to adjudicate between them. The project pitted the Global Neuronal Workspace Theory (GNWT), championed by Stanislas Dehaene and Jean-Pierre Changeux, against Integrated Information Theory (IIT), developed by Giulio Tononi and Christof Koch.

Over 20 laboratories across six countries contributed to the project, using a shared experimental protocol that included visual masking, attentional blink paradigms, and no-report paradigms designed to dissociate conscious perception from task-related cognitive processes.

What the Experiments Found

Neither theory emerged unscathed. GNWT had predicted that conscious perception would reliably correlate with late and widespread activation in frontoparietal networks. The COGITATE data showed this signature present in many — but not all — conscious trials, while also detecting it in some unconscious trials, undermining the claim that it constitutes a specific marker of consciousness.

IIT, by contrast, predicted that the posterior cortical hot zone — particularly the temporo-parietal-occipital junction — would show high integrated information (phi) during conscious states. While the data confirmed elevated phi during conscious perception, the correlation was weaker than the theory's proponents had predicted, and the computational demands of measuring phi in real time proved a significant practical limitation.

Implications for the Field

'The COGITATE results have been sobering for both camps,' said Dr. Lucia Melloni, the project's coordinating investigator at the Max Planck Institute for Empirical Aesthetics. 'But they have also been incredibly productive. We now know more precisely what each theory explains well and where it falls short.'

The study has galvanized a new wave of theoretical work. Researchers are now exploring hybrid models that incorporate elements of both GNWT and IIT, as well as turning to alternative frameworks such as Higher-Order Thought Theory and Predictive Processing approaches.

Sources:

Melloni et al., COGITATE collaboration papers, Nature Human Behaviour (2024-2025); Dehaene & Changeux, GNWT reviews; Tononi et al., IIT 4.0 framework. — Editorial Dept.

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