Antonio Damasio and Hanna Damasio (2022), Brain 145(7):2231–2235, an Essay — DOI 10.1093/brain/awac194
Key takeaways
- What consciousness is. It occurs when the contents of mind are “spontaneously identified as belonging to a specific owner”: our own organism, located in its body. It “should not be confused with the mere integration of images, or with the scale of that integration, or with the attention accorded to some images in detriment of others.”
- Sensing is not minding. Bacteria and plants sense and respond, with no nervous system and no representations. Minds are streams of mapped images built by nervous systems: mostly exteroceptive, and a less dominant interoceptive stream of homeostatic feelings.
- The hypothesis. The continuous flow of homeostatic feelings, salient (hunger, pain, malaise) or close to equilibrium (feelings of existence), identifies the mind with its organism. Each feeling “is itself spontaneously and automatically conscious”, and feelings “lend” consciousness to exteroceptive images, which need feelings present to be conscious. Feelings were “the inaugural phenomena of consciousness”, selected because they gave overt, not only covert, guidance of life regulation.
- The mechanism. Interoceptive axons are not myelinated, make frequent non-synaptic contacts and lack a systematic blood–brain barrier (Table 1), so viscera and circulating molecules act directly on the neurons that map them. Map and object “commingle”, which no exteroceptive map can do with a landscape. That is why feelings are “hybrid”.
- Loss of consciousness. Small lesions of the posterior brainstem (nucleus tractus solitarius, parabrachial nucleus, periaqueductal grey), where body signals are first integrated, cause coma, while “even extensive lesions of the cerebral cortex may not”. General anaesthetics act on the membrane-level “sensing and detecting” below feeling, which is why they also halt plant activity.
Standing in the record
Filed on 2026-10-03 at the owner’s request. No anthology topic holds a theory of consciousness grounded in interoception, and the essay carries no instruction for machine-learning practice. Its last claim, that consciousness “cannot be found in inanimate objects, regardless of how complex they may be”, bears on machine consciousness only as a denial.
It is the readable form of LIT-387. The Damasios’ Neural Computation paper (2023, Deferred, unread) has an abstract that states this essay’s opening summary nearly sentence for sentence: the identification of contents with an owner, the two kinds of homeostatic feeling, the inaugural-phenomena claim, the two-way interaction and the hybrid. The Neural Computation paper was received in January 2022, before this essay, so the two are parallel statements, not one building on the other. A reader of this essay has the thesis of LIT-387, but not whatever argument or evidence that paper adds. The same authors also published “Homeostatic Feelings and the Emergence of Consciousness” (Journal of Cognitive Neuroscience 36(8), 2024), which the record does not hold.
It carries forward Damasio and Carvalho (2013), LIT-388 (NOTE-330), to
consciousness. That paper made feeling the felt read-out of interoceptive
maps, placed the first whole-body maps in the upper brainstem and proposed
unmyelinated fibres as the root of sentience. This essay keeps all three
and adds two things: that feelings are what make any content conscious,
and that the unmyelinated, barrier-free physiology makes feeling a hybrid of
body and map rather than a map. It does not cite the 2013 paper (it cites
Carvalho and Damasio’s 2021 Bioessays synthesis and Parvizi and Damasio on
brainstem coma), so no extends is declared.
It rivals IIT 3.0, LIT-445. The essay names “integration of information” (citing Tononi et al. 2016) among the processes that prominent solutions study in place of subjectivity, and says consciousness should not be confused with the integration of images. IIT identifies consciousness with integrated information in any physical substrate; this essay ties it to living bodies with nervous systems and denies it to inanimate objects of any complexity. Each account excludes the other’s, and neither tests the other.
It rivals the global neuronal workspace, LIT-631. The essay puts Dehaene’s Consciousness and the Brain with the solutions that target attention instead of subjectivity, and makes three claims the workspace review opposes: consciousness is not attentional selection; extensive cortical lesions may spare it while small brainstem lesions abolish it, where the review ties the level of consciousness to frontal-parietal hubs and their long-range connections; and general anaesthetics act at the membrane-level sensing below feeling, where the review argues their common action is to disconnect the workspace. The review is about access by its own stipulation; the essay is about the identification of contents as one’s own. They are rival accounts of what is lost in coma and under anaesthesia.
How it bears on what else the record holds:
- THEORY-045 (felt affect as the experience of the body’s regulatory state) is sourced from Barrett (LIT-542) and Damasio and Carvalho. This essay supports its clause that such feeling is present “throughout waking experience”: feelings of existence are “generated continuously in the awake state”. On the theory’s open question, map or prediction, the essay says nothing about prediction; its answer is a third option, that the feeling is partly constituted by the body state it maps.
- THEORY-090 (subcortical alarm consciousness) cites LIT-388 for its subcortical clause. This essay adds the clinical form of that claim: posterior brainstem lesions cause coma and extensive cortical lesions may not. On the function clause it does not choose between alarm and THEORY-101’s common currency: feelings give “knowledge” that guides regulation overtly, and its examples (pain, hunger, well-being permitting exploration) are corrections, not overrides or trade-offs.
- Barrett (LIT-542) is not mentioned. Where Barrett makes feeling a prediction issued by cortex, this essay makes it a hybrid built from the brainstem down.
- Chalmers’s “Facing Up” (LIT-406) is the essay’s first reference, cited for the notion that the problem “cannot be solved, at least within the realm of biology”. The essay states its biological answer without engaging Chalmers’s argument.
- Seth (LIT-135) and this essay both tie consciousness to the regulation of a living body; Seth argues through prediction, this essay through the physiology of interoceptive fibres.
- Plants (LIT-193). The essay classes plant sensing as sensing without minding, and cites Baluška et al. on anaesthetics halting plant activity as evidence that anaesthetics act below feeling, not as evidence that plants feel.