The Behavioral and brain sciences
July 22, 2025
François Stockart, Maor Schreiber, Pietro Amerio et al.
20 citations
The scope of unconscious processing remains hotly debated, driven by diverse methods for manipulating and measuring perceptual awareness. Through dialogue among researchers with varied theoretical backgrounds, ten recommendations and nine outstanding issues are provided for designing experimental paradigms, analyzing data, and reporting results. These guidelines aim to evoke discussion about norms in studying unconscious processes and help researchers make informed decisions. While some recommendations may not align with existing approaches and will likely evolve, they are intended to foster a more convergent understanding of the extent and limits of unconscious processing.
Trends in Cognitive Sciences
December 17, 2025
Liad Mudrik, Nathan Faivre, Michael Pitts et al.
5 citations
A major controversy in consciousness science divides sensory and cognitive theories. Reexamining Block's 1995 distinction between phenomenal consciousness (P) and access consciousness (A), the authors argue that P and A are not two different types of consciousness but two necessary conditions for consciousness. This conceptual shift helps resolve unresolved questions about neural mechanisms, functions of consciousness, and its relationship with attention. The proposal motivates selective unification across different classes of theories.
Cambridge University Press eBooks
April 23, 2026
Michael H. Herzog, Aaron Schurger, Adrien Doerig
This paper critically examines quantum theories of consciousness, particularly orchestrated objective reduction (OrchOR), which proposes that proto-conscious events occur throughout the universe but full consciousness arises only at the subcellular level in neuronal microtubules. The authors outline challenges with this approach, arguing that existing theories linking consciousness to neural processes are insufficient and that quantum-based explanations face significant conceptual and empirical difficulties.
Neuroscience of Consciousness
January 1, 2026
Vikas N O'Reilly-Shah, Alessandro Maria Selvitella, Aaron Schurger
The unfolding argument claims that causal structure cannot matter for consciousness because any recurrent neural network can be replaced by a feedforward network with the same input-output behavior. This paper shows a boundary condition: when a network has rapid plasticity—weights that change quickly based on history—the equivalence fails. Mathematical proofs demonstrate that such systems encode information in ways a static feedforward network cannot capture, including history-dependent dynamics, complex temporal encoding, and perturbational instability. The results do not prove that recurrence or plasticity is necessary for consciousness, but they show that the unfolding argument does not block empirical tests of whether these properties matter.
Consciousness and Cognition
February 1, 2022
Michael H Herzog, Aaron Schurger, Adrien Doerig
The authors argue that integrated information theory (IIT) cannot be a scientific theory of consciousness because it relies on pure first-person experience as a foundation, which is not measurable except through reports, brain activity, and their relationship. Science requires measurements and data, not assertions of ground truth independent of data. No experiment based on third-person data can test IIT as a theory of consciousness. The authors contend that IIT's conception of consciousness is fully dissociated from measurable things, implying that both the level and content of consciousness are epiphenomenal and lack causal power. This leads to a form of dissociative epiphenomenalism that undermines trust in reports about first-person experiences, which are the basis for IIT's own axioms, meaning accepting IIT leads to rejecting its axioms.
Neuroscience of Consciousness
January 21, 2022
Aaron Schurger, M. Graziano
Consciousness is inherently subjective, making it difficult to study with objective scientific methods. The search for neural correlates of consciousness (NCCs) has been a productive workaround, focusing on brain activity reliably linked to conscious experience. However, this approach was never meant to explain consciousness, only to sidestep the challenge. The authors argue that most modern accounts of consciousness are not true theories but rather laws that describe what they cannot explain, analogous to Newton's description of gravity. They contend that attention schema theory is an exception, qualifying as an explanatory theory that goes beyond mere description.
Cognitive Neuroscience
July 14, 2020
Adrien Doerig, Aaron Schurger, M. Herzog
Consciousness research has produced many competing theories, ranging from computational to quantum approaches, more than in other natural sciences. This abundance may stem from a lack of clear criteria for how empirical data should constrain such theories. The authors argue consciousness is empirically well-defined and propose a checklist of criteria that empirical theories of consciousness must address. They review 13 influential theories against these criteria, revealing their relative strengths and weaknesses from a strictly empirical perspective.
Consciousness and Cognition
July 1, 2019
Adrien Doerig, Aaron Schurger, K. Hess et al.
Theories that identify consciousness with specific causal structures in the brain, such as those requiring feedback loops, are either false or unscientific. Using theorems from computation theory, the authors demonstrate that causal structure theories—including Information Integration Theory (IIT) and Recurrent Processing Theory (RPT)—cannot be empirically tested because any causal structure can be realized by systems that lack consciousness. This undermines the claim that feedforward systems are never conscious and feedback systems always are. The argument suggests that consciousness research should focus instead on functional explanations, such as global workspace or higher-order theories, which are compatible with diverse neural implementations.
Proceedings of the National Academy of Sciences of the United States of America
April 21, 2015
Aaron Schurger, Ioannis Sarigiannidis, Lionel Naccache et al.
Conscious perception may involve the transient stabilization of distributed cortical networks, corresponding to a global brain-scale decision. Pattern-similarity analyses of MEG/EEG data from participants viewing threshold-level visual stimuli showed a decrease in variability across trials after stimulus onset, followed by a divergence in variability based on subjective report (seen/unseen), with seen trials exhibiting less variability. Within-trial stability alone could classify individual trials as seen or unseen. In patients with disorders of consciousness exposed to auditory stimuli, stability metrics diverged according to clinically diagnosed level of consciousness. Differences in signal strength could not account for these results.
Michael H Herzog, Aaron Schurger, Adrien Doerig
preprint
The authors argue that integrated information theory (IIT) cannot be a scientific theory of consciousness because it relies on pure first-person experience as ground truth, which is not measurable except through reports, brain activity, and their relationship. They contend that science requires testable data, and no experiment based on third-person data can test IIT as a theory of consciousness. The authors further claim that IIT implies consciousness is epiphenomenal—lacking causal power—and that accepting IIT leads to rejecting its own axioms, since reports about first-person experiences, which are the foundation for those axioms, become untrustworthy under the theory.