# Consciousness

What warrants attributing experience across unfamiliar organisms or substrates? Covers proposed indicators, competing theories, and the limits of transferring evidence between humans, animals and machines.

## Theories and discriminating tests

- **Comparing consciousness theories** - Compares higher-order, workspace, recurrent/predictive and integrated-information approaches. Differences concern explanatory targets as well as proposed mechanisms, complicating empirical comparisons between theories. [Seth and Bayne 2022](<https://www.nature.com/articles/s41583-022-00587-4> "Theories of consciousness; Nat. Rev. Neurosci.").
- **Adversarial consciousness tests** - Preregistered visual tests in 256 people challenge sustained posterior synchrony and offset ignition predictions, while supporting others from integrated-information and workspace theories. The tests concern specified neural implementations. [Cogitate Consortium et al. 2025](<https://www.nature.com/articles/s41586-025-08888-1> "Adversarial testing of global neuronal workspace and integrated information theories of consciousness; Nature").

## Indicators beyond familiar brains

- **Cortical organoid activity** - Developing cortical organoids produce nested oscillations dependent on excitatory and inhibitory signaling. Selected electrical features resemble preterm EEG; the study measures network maturation, not subjective experience. [Trujillo et al. 2019](<https://doi.org/10.1016/j.stem.2019.08.002> "Complex oscillatory waves emerging from cortical organoids model early human brain network development; Cell Stem Cell").
- **Animal consciousness profiles** - Organizes evidence along perceptual richness, evaluative richness, integration within and across time, and self-consciousness. Species can differ along several dimensions; the proposed profiles are hypotheses requiring comparative tests. [Birch et al. 2020](<https://doi.org/10.1016/j.tics.2020.07.007> "Dimensions of Animal Consciousness; Trends Cogn. Sci.").
- **AI consciousness indicators** - Derives candidate indicators from neuroscientific theories and examines AI architectures against them. These are theory-dependent assessment criteria; satisfying them is not a validated test of subjective experience. [Butlin et al. 2023](<https://arxiv.org/abs/2308.08708v3> "Consciousness in Artificial Intelligence: Insights from the Science of Consciousness; arXiv").
- **Organoid sentience criteria** - Birch proposes brainstem-like regulation of needs, arousal and sleep-wake cycles as a warning threshold for organoid oversight. This precautionary criterion is theory-dependent, not an experimentally validated test of experience. [Birch 2024](<https://doi.org/10.1093/9780191966729.003.0012> "Neural Organoids; The Edge of Sentience, Oxford University Press (book chapter)").

## Open questions

- Which observations discriminate competing explanations rather than satisfy several theories at once?
- Which proposed indicators remain justified when the biological or computational implementation changes?

## Related topics

- [Hyperorganism](https://hyperorganism.github.io/)
- [Basal cognition](https://hyperorganism.github.io/basal-cognition/) - Behavioral capacities have operational tests that do not automatically establish experience.
- [DishBrain and its interpretation](https://hyperorganism.github.io/biohybrid-systems/#living-actuators-and-neural-interfaces) - The claim, critique and reply distinguish measured game performance from disputed uses of sentience.
- [Recognizing life](https://hyperorganism.github.io/recognizing-life/) - Life detection and consciousness attribution require different evidence.