Abstract:

Understanding the neuronal mechanisms that support consciousness is a fundamental question in neuroscience. Several competing theories have been proposed. To accelerate research, the predictions of these theories must be tested together within a unified framework. This is the objective of COGITATE, an adversarial collaboration on Global Neuronal Workspace Theory (GNWT) and Integrated Information Theory (IIT). This talk focuses on the predictions made by the two theories regarding activation and inter-areal communication when a visual stimulus is consciously perceived. GNW predicts phasic activation in the prefrontal cortex at both stimulus onset and offset, while IIT predicts content-specific sustained activation in the posterior cortex during stimulus presentation. Additionally, GNW anticipates stronger synchronization between the prefrontal and category-selective areas within the ‘ignition’ time window (300-500 ms after stimulus onset), whereas IIT expects sustained synchronization between the early visual cortex and category-selective areas. The results revealed the presence of the predicted sustained alpha/gamma activity in the posterior cortex. Regarding inter-areal communication, content-specific synchronization was found between frontal and early visual areas. By integrating various neuroscientific techniques (MEG, fMRI, intracranial EEG) and testing further theoretical predictions (e.g., decoding of conscious content), we provide evidence that supports or refutes the predictions made by the two theories, thereby contributing to the clarification of how consciousness arises in the human brain.

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