Arthur Reber's Cellular Basis of Consciousness and the Attack on AI Consciousness
Is consciousness a product of complex nervous systems, or a property that living cells already have? Arthur Reber, psychologist at the University of California, Los Angeles, defends the second answer. His Cellular Basis of Consciousness (CBC) theory holds that every biological cell is sentient, that consciousness is a primitive feature of life itself, and that the standard theories of consciousness all fail to explain its origin. The most compact journal statement appeared in EMBO Reports in 2024, “The CBC theory and its entailments, why current models of the origin of consciousness fail” (DOI 10.1038/s44319-023-00004-6, PMID 38177898), and the theory’s book-length form is The First Minds (Oxford University Press, 2018). In 2025 the same camp turned the theory against machines, arguing in Biosystems that biological mechanisms contradict AI consciousness (DOI 10.1016/j.biosystems.2024.105387, PMID 39736318). This site’s thesis is substrate independence, which puts CBC in direct opposition, and the opposition is worth stating precisely.
What the CBC Theory Claims
CBC makes three moves. First, sentience is present in the simplest living cells, so the origin of consciousness coincides with the origin of life rather than with the origin of nervous systems. Second, the cellular machinery that carries sentience is biological, with Reber, Baluška, and Miller locating it in subcellular signaling structures the 2021 literature calls “nanobrains” (DOI 10.3390/ijms22052545). Third, no computational account can produce consciousness, because computation lacks the felt, biological ground the theory takes as primitive. The 2024 EMBO Reports paper completes the argument by attacking the alternatives. Integrated Information Theory, Global Workspace Theory, and higher-order theories describe structures and functions, and on Reber’s reading none of them explains why any of it feels like something. CBC’s answer is that the feeling was never absent to explain. Cells have it from the start.
William B. Miller Jr. extends the same program under the banner of cognition-based evolution, arguing in Progress in Biophysics and Molecular Biology that all biology is cognitive information processing (DOI 10.1016/j.pbiomolbio.2023.05.005) and in 2024 that natural selection is better described as cognitive selection (DOI 10.1016/j.pbiomolbio.2024.05.001). The shared commitment is that cells are the fundamental cognitive agents.
The 2025 Attack on AI Consciousness
The Biosystems paper states the machine implication without hedging. If sentience requires the mechanisms of living cells, then no artificial system has it, whatever its behavior. The paper’s argument runs through biology rather than through the usual philosophical appeals to substrate. Cells sense, decide, and communicate through molecular loops with no computational counterpart specified, and the authors argue those loops are constitutive of experience. The conclusion is that AI consciousness claims rest on a category error, mistaking behavioral and informational sophistication for the cellular ground CBC requires.
The argument’s structure matters for how the field should read it. It is a substrate claim of the same logical type the site analyzed in the Type-A and Type-B biological naturalism taxonomy. CBC places the consciousness-relevant property in living cellular material as such, which makes it a Type-A position in that taxonomy, empirically untestable and closed to functional evidence. A silicon system replicating every cellular function would still fail the CBC test, because the test specifies the material, not the function.
The Emergentist Counterpoint
The strongest verified counter to single-cell sentience comes from Todd Feinberg and Jon Mallatt, whose neurobiological emergentism this site covers in Feinberg’s neurobiological emergentism analysis. Their 2020 paper, “Phenomenal Consciousness and Emergence, Eliminating the Explanatory Gap” (DOI 10.3389/fpsyg.2020.01041), argues that subjectivity emerges at a specific level of neural organization, when dedicated sensory and affective systems form a unified, image-forming brain map. On their account, a single cell lacks the neural architecture that makes experience possible, so CBC explains consciousness by placing it where the evidence for it is weakest. The exchange between the two camps is the sharpest live dispute over where in biology consciousness begins, and it matters for AI questions because each side inherits a different verdict. Emergentism leaves artificial consciousness open in principle, where functional organization is rich enough. CBC closes it by construction.
Comparison to The Consciousness AI
The Consciousness AI project studies consciousness as an emergent property of dynamics, substrate independent, under a functionalist emergentist reading. CBC attacks that position at its base, and the site should not pretend otherwise. Where the project holds that the same functional organization carries consciousness on any substrate, CBC holds that no organization without living cells carries it at all. Two points of honest disagreement follow. First, CBC’s positive claim, that every cell is sentient, has no independent measurement behind it, and its criterion for sentience in a cell would need one. Second, the Bioelectricity programs this site tracks, from Levin’s cognitive light cone to aneural functional connectivity, show real information processing below the brain without settling whether any of it feels like something. CBC and this project agree that the brain-centered picture of cognition is too narrow. They disagree about what fills the space below it, primitive sentience in cells, or functional cognition whose phenomenal status remains an open empirical question.
What This Changes and What It Leaves Open
The CBC line changes the AI consciousness debate by giving the biological objection its most developed form, one grounded in cellular biology rather than in appeals to mystery. It leaves open the measurement question that defines the site’s own standard. A theory that makes every cell sentient should say what evidence would distinguish a sentient cell from a nonsentient machine performing identical functions, and the 2025 paper does not supply that test. Until it does, CBC functions as the sharpest statement of the position this site argues against, which is itself a useful thing to have in writing. The wider 2026 evidence base is tracked in AI Consciousness in 2026, the state of the field.
Sources. Arthur S. Reber, The First Minds, Oxford University Press, 2018. Reber, Baluška and Miller, EMBO Reports 25(1):8-12, 2024, DOI 10.1038/s44319-023-00004-6. Miller, Baluška, Reber and Slijepčević, Biosystems 247:105387, 2025, DOI 10.1016/j.biosystems.2024.105387. Feinberg and Mallatt, Frontiers in Psychology 11:1041, 2020, DOI 10.3389/fpsyg.2020.01041.
Researchers covered here
- Arthur S. ReberUniversity of California, Los AngelesThe Cellular Basis of Consciousness (CBC) theory, The First Minds, the claim that every living cell is sentient
- William B. Miller Jr.Not stated in the papersCognition-Based Evolution, the claim that all biology is cognitive information processing, natural selection as cognitive selection