paper:rouleau-levin-brains-and-where-else-2026Brains and where else? Mapping theories of consciousness to unconventional embodiments
TL;DR
Rouleau and Levin's 2026 analysis in *Philosophical Transactions of the Royal Society A* (384, issue 2320) demonstrates that the functional and operational principles underlying most contemporary theories of consciousness (ToCs) are not substrate-specific to neural tissue—brains are privileged by convention, not by theoretical necessity. Surveying major current ToCs and mapping their mechanistic requirements against findings from evolutionary biology, developmental bioelectricity, and synthetic bioengineering, the paper shows that algorithms and mechanisms characteristic of neural cognition have ancient pre-neural roots: minds, on this view, preceded brains. The analytical instrument introduced is a systematic substrate-mapping procedure that asks, for each ToC, whether its load-bearing features specifically pick out brains or whether those features are realizable in unconventional embodiments including cells, tissues, organoids, and life-technology chimeras. Notably, several contemporary theorists—responding to advances in AI and organoid bioengineering—have already begun extending their frameworks to synthetic systems, lending empirical traction to the mapping. Published in a theme issue on world models in natural and artificial intelligence (DOI: 10.1098/rsta.2025.0082), the paper argues this implies that the science of consciousness must remain open to inner perspective in unconventional substrates, and that a ToC which cannot account for distributed, pre-neural, or synthetic minds is underdetermined by the biological evidence it purports to explain.
What to take away
- 1. Across every major contemporary ToC surveyed, the functional principles cited as constitutive of consciousness are realizable in non-neural substrates including single cells, tissues, and life-technology chimeras—not exclusively in brains.
- 2. Evolutionary biology and developmental bioelectricity demonstrate that the core algorithms occurring in vertebrate brains have ancient pre-neural origins, supporting the claim that minds preceded brains as an evolutionary matter.
- 3. The paper introduces a substrate-mapping procedure that systematically asks, for each ToC, whether its load-bearing features specifically select neural tissue or are substrate-agnostic, providing a replicable analytical template for evaluating any ToC against unconventional embodiments.
- 4. Published in *Philosophical Transactions of the Royal Society A* volume 384, issue 2320 (DOI: 10.1098/rsta.2025.0082) within the theme issue 'World models in natural and artificial intelligence', the work situates consciousness theory inside the broader discourse on artificial and biological world-modelling.
- 5. Several contemporary theorists have independently begun extending their ToCs to synthetic systems—specifically in response to advances in AI and organoid bioengineering—providing convergent evidence that the field is already moving away from brain-exclusive framings.
- 6. The brain's privileged status in consciousness research is attributed more to disciplinary convention than to any specific theoretical constraint within existing ToCs, a strong claim grounded in the substrate-mapping analysis.
- 7. The paper raises the open question of whether problem-solving competency metrics used in diverse intelligence research—which focus on externally observable behavior in cells and tissues—can be mapped onto the internal-perspective criteria required by ToCs, or whether a new bridging framework is needed.
- 8. A replicable methodological choice is the two-step analysis: (a) identify the minimal mechanistic conditions each ToC posits, then (b) survey whether those conditions are documented in non-neural biological or synthetic systems via the evolutionary and bioelectricity literature.
- 9. The life-technology chimera substrate is treated as a test case alongside organoids, with both representing synthetic bioengineering contexts where ToC applicability can be probed empirically rather than merely philosophically.
- 10. Rouleau and Levin predict that a ToC adequate to the biological evidence must remain open to minds in unconventional embodiments, implying that theories which build neural architecture into their explanatory core are falsifiable by pre-neural and synthetic cognition data.
Peer brief — for seminar discussion
Rouleau and Levin set out to do something deceptively simple: take the most prominent contemporary theories of consciousness and ask whether their load-bearing principles specifically require brains, or whether those principles are realizable in other substrates. The analytical instrument, a substrate-mapping procedure, works in two steps—extract the minimal mechanistic conditions each ToC posits as sufficient or necessary for inner perspective, then consult the evolutionary biology, developmental bioelectricity, and synthetic bioengineering literature to determine whether those conditions are documented outside neural tissue. The paper was published in *Philosophical Transactions of the Royal Society A*, volume 384, issue 2320, in a theme issue on world models in natural and artificial intelligence (DOI: 10.1098/rsta.2025.0082, published 14 May 2026). The load-bearing finding is that, across every ToC examined, the functional and operational principles cited are not confined to neural substrates. Cells, tissues, organoids, and life-technology chimeras satisfy the mechanistic descriptions these theories offer, and the ancient pre-neural roots of the algorithms at issue—established through developmental bioelectricity research—suggest that minds preceded brains rather than being constituted by them. Brains, on this reading, are not theoretically privileged; they are conventionally privileged because the field has historically constrained itself to neural cases. The implication the paper presses is normative and programmatic: the science of consciousness cannot be adequately tested or falsified if it considers only one substrate class. Several contemporary theorists have already moved in this direction, extending their frameworks to AI and organoid systems independently, which the paper treats as convergent corroboration. A critical reader would push back on circularity in the substrate-mapping procedure: it identifies mechanistic conditions as described by each ToC, but those descriptions were themselves formulated with neural systems in mind and may be too abstractly specified to be genuinely substrate-agnostic rather than merely substrate-unspecific. Showing that a condition is not explicitly neural is not the same as showing it is positively satisfied in, say, bioelectric tissue networks. An alternative method that could have sharpened this is a predictive-model approach—deriving concrete, testable signatures that each ToC predicts should differ between neural and non-neural substrates, then checking empirical data against those predictions, rather than relying on the looser criterion of whether mechanistic descriptions are in principle compatible with non-neural instantiation. The paper also advances a hypothesis worth naming: that a ToC which builds neural architecture into its explanatory core is falsifiable by pre-neural and synthetic cognition data. This is a strong and productive prediction, but it depends on accepting that bioelectric problem-solving competency in cells and tissues constitutes evidence about inner perspective—a bridge that, as the paper itself acknowledges, the diverse intelligence literature has not yet fully constructed.
Methods (1)
- Organoid bioengineeringExperimental technology enabling testing of consciousness theories in novel synthetic systems.
Frameworks (1)
- Diverse IntelligenceResearch program studying intelligence at multiple scales and substrates; proposed as relevant to implications of mnemonic improvisation.
Findings (3)
- Several contemporary theorists have explicitly applied their theories to synthetic systems in light of AI and organoid bioengineering developments.
A descriptive finding that some theorists are already extending their frameworks beyond brains.
- The operations and functional principles of most contemporary theories of consciousness are not confined to neural substrates.
Primary empirical result from comparative analysis of major consciousness theories.
- In analysis of current ToCs, the operations and functional principles of most ToCs are not confined to neural substrates.
This is the main empirical result from mapping the operational characteristics of popular theories of consciousness.
Claims (5)
- The focus on brains as substrate of consciousness is driven by convention rather than by the specific content of existing theories of consciousness.
Central empirical claim: authors surveyed major ToCs and found their operations are not confined to neural substrates.
- Most work in diverse intelligence emphasizes externally observable problem-solving competencies in unconventional media.
A characterization of the diverse intelligence field provided by the authors.
- The science of consciousness should remain open to minds in unconventional embodiments.
The normative conclusion of the paper, urging the field to not prematurely exclude non-brain substrates.
- The features emphasized by theories of consciousness are not unique to brains.
The core argument that ToC functional principles do not pick out brains as a privileged substrate for inner perspective.
- Minds may have preceded brains in evolutionary history.
Interpretive claim grounded in evidence from evolutionary biology and developmental bioelectricity.
Hypotheses (1)
- The science of consciousness should remain open to the possibility of minds in unconventional embodiments.
Normative conclusion and forward-looking hypothesis based on theoretical and empirical evidence reviewed.
Questions (1)
- What features of each theory specifically pick out brains as a privileged substrate of inner perspective, or do the features emphasized by the theory occur elsewhere?
The central research question that drives the paper's analysis.
Original abstract (expand)
It is assumed that a useful theory of consciousness (ToC) will explain why consciousness is associated with brains. However, the findings of evolutionary biology, developmental bioelectricity and synthetic bioengineering reveal ancient pre-neural roots of many mechanisms and algorithms occurring in brains: minds may have preceded brains. Most work in the emerging field of diverse intelligence emphasizes externally observable problem-solving competencies in unconventional media, such as cells, tissues and life-technology chimeras. Here, we inquire about the implications of these developments for ToCs. Specifically, we analyse popular current ToCs to ask: What features of each theory specifically pick out brains as a privileged substrate of inner perspective, or do the features emphasized by the theory occur elsewhere? We find that the operations and functional principles of most ToCs are not confined to neural substrates, and that the focus on brains is more driven by convention than by the specific content of existing ToCs. Encouragingly, several contemporary theorists have made explicit efforts to apply their theories to synthetic systems in light of recent technological developments in artificial intelligence and organoid bioengineering. We suggest that the science of consciousness should remain open to minds in unconventional embodiments. This article is part of the theme issue 'World models in natural and artificial intelligence'.
Related work— refs + corpus + external arXiv
Cited / in-corpus / arXiv badges show which signals surfaced each row. Multi-source rows weighted higher.
- Technological Approach to Mind Everywhere: An Experimentally-Grounded Framework for Understanding Diverse Bodies and Mindscitedin corpus2022≈ 84%
- Collective intelligence: A unifying concept for integrating biology across scales and substratescitedin corpus2024≈ 82%
- The computational boundary of a 'self': developmental bioelectricity drives multicellularity and scale-free cognitioncitedin corpus2019≈ 82%
- ≈ 87%
- The biogenic approach to cognitionin corpus2005≈ 87%
- The Machine Consciousness Hypothesisin corpus≈ 87%
- ≈ 87%
- Consciousness in the universecited2013≈ 87%
- ≈ 86%
- ≈ 86%
- ≈ 86%
- Predictive processing as a systematic basis for identifying the neural correlates of consciousnesscited2020≈ 86%
- Consciousness and Complexitycited1998≈ 86%
- Cognition in some surprising placescited2021≈ 86%
- A Theory of Consciousness from a Theoretical Computer Science Perspective: Insights from the Conscious Turing MachineManuel Blum Lenore Blum2022≈ 86%
- ≈ 86%
- ≈ 86%
- ≈ 86%
- ≈ 86%
- ≈ 85%
- ≈ 85%
- On the independence between phenomenal consciousness and computational intelligenceSara Lumbreras Eduardo C. Garrido Merch\'an2022≈ 85%
- Elements of Consciousness and Cognition. Biology, Mathematic, Physics and Panpsychism: an Information Topology PerspectivePierre Baudot2018≈ 85%
- ≈ 85%
- ≈ 85%
- ≈ 85%
- ≈ 85%
- Consciousness is entailed by compositional learning of new causal structures in deep predictive processing systemsV.A. Aksyuk2024≈ 85%
- ≈ 84%
- The brain versus AI: World-model-based versatile circuit computation underlying diverse functions in the neocortex and cerebellumShogo Ohmae and Keiko Ohmae2024≈ 84%
+26 more
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Cross-corpus bridges (12)
same_concept_as · Nomic cosineExternal markdown files that talk about the same concept as this entity.
- aboutblank_kbCan engineering novel embodied minds with cognitive capacities currently unique to biological systems be achieved?questions/can-engineering-novel-embodied-minds-with-cognitive-capacities.md0.852
- aboutblank_kbCan consciousness be attributed to systems beyond brains and neurons?questions/can-consciousness-be-attributed-to-systems-beyond-brains.md0.845
- aboutblank_kbHow can cognition exist at scales beyond the nervous system, and what are the computational principles underlying cellular and genetic information processing?questions/how-can-cognition-exist-at-scales-beyond-the.md0.839
- aboutblank_kbCan consciousness and sentience be achieved by biological substrates other than nervous tissue?questions/can-consciousness-and-sentience-be-achieved-by-biological.md0.838
- aboutblank_kbCan artificial systems be designed to achieve consciousness through bioelectric or similar mechanisms?questions/can-artificial-systems-be-designed-to-achieve-consciousness.md0.832
- aboutblank_kbWhat mechanisms enable basal cognition in non-neural substrates?questions/what-mechanisms-enable-basal-cognition-in-nonneural-substrates.md0.830
- aboutblank_kbCan consciousness or intelligence emerge from or reside in non-physical patterns and excitable media, not just physical substrates?questions/can-consciousness-or-intelligence-emerge-from-or-reside.md0.829
- aboutblank_kbHow can a unified framework account for consciousness across biological, artificial, and hybrid systems?questions/how-can-a-unified-framework-account-for-consciousness.md0.827
- aboutblank_kbIs it possible that sentient systems exist using mechanisms fundamentally different from human neural consciousness?questions/is-it-possible-that-sentient-systems-exist-using.md0.827
- aboutblank_kbWhat are the implications of distributed cognition in biological systems for theories of consciousness?questions/what-are-the-implications-of-distributed-cognition-in.md0.827
- aboutblank_kbHow can we understand consciousness and mind in ways applicable to both biological and artificial systems?questions/how-can-we-understand-consciousness-and-mind-in.md0.824
- aboutblank_kbCan we meaningfully recover and understand the consciousness and cognition of minds with radically different substrates?questions/can-we-meaningfully-recover-and-understand-the-consciousness.md0.824