# Integrated information theory (IIT) 4.0: Formulating the properties of phenomenal existence in physical terms

arXiv: https://arxiv.org/abs/2212.14787 · HTML: https://mlsanity.com/paper/2212.14787/

## Key facts

- Cited by 21 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 30 Dec 2022.

## Built on by (most cited first, 21 of 21)

- [Causal Semantic Communication for Digital Twins: A Generalizable Imitation Learning Approach](https://mlsanity.com/paper/2304.12502/) (2023)
- [Is artificial consciousness achievable? Lessons from the human brain](https://mlsanity.com/paper/2405.04540/) (2024)
- [Dissociating Artificial Intelligence from Artificial Consciousness](https://mlsanity.com/paper/2412.04571/) (2024)
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- [Preliminaries to artificial consciousness: a multidimensional heuristic approach](https://mlsanity.com/paper/2403.20177/) (2024)
- [A Disproof of Large Language Model Consciousness: The Necessity of Continual Learning for Consciousness](https://mlsanity.com/paper/2512.12802/) (2025)
- [Minimal Computational Preconditions for Subjective Perspective in Artificial Agents](https://mlsanity.com/paper/2602.02902/) (2026)
- [Report on Candidate Computational Indicators for Conscious Valenced Experience](https://mlsanity.com/paper/2404.16696/) (2024)
- [The Epistemic Asymmetry of Consciousness Self-Reports: A Formal Analysis of AI Consciousness Denial](https://mlsanity.com/paper/2501.05454/) (2024)
- [Can "consciousness" be observed from large language model (LLM) internal states? Dissecting LLM representations obtained from Theory of Mind test with Integrated Information Theory and Span Representation analysis](https://mlsanity.com/paper/2506.22516/) (2025)
- [Artificial Consciousness as Interface Representation](https://mlsanity.com/paper/2508.04383/) (2025)
- [Consciousness in Artificial Intelligence? A Framework for Classifying Objections and Constraints](https://mlsanity.com/paper/2511.16582/) (2025)
- [Body-Grounded Perspective Formation and Conative Attunement in Artificial Agents](https://mlsanity.com/paper/2605.16728/) (2026)
- [AI and Consciousness](https://mlsanity.com/paper/2510.09858/) (2025)
- [Toward IIT-Inspired Consciousness in LLMs: A Reward-Based Learning Framework](https://mlsanity.com/paper/2601.22786/) (2026)
- [Hidden Coalitions in Multi-Agent AI: A Spectral Diagnostic from Internal Representations](https://mlsanity.com/paper/2605.06696/) (2026)
- [Intrinsic Computational Functionalism and Simulated Consciousness](https://mlsanity.com/paper/2606.15348/) (2026)
- [Perspective Latents as an Architectural Condition for Causal Emergence in Active Inference Agents](https://mlsanity.com/paper/2607.20708/) (2026)
- [Categorical AI phenomenology: A first-person approach](https://mlsanity.com/paper/2608.20420/) (2026)
- [Gradland: On Phenomenal Experience, Differentiated Across Many Dimensions](https://mlsanity.com/paper/2609.09306/) (2026)
- [A Mathematical Model of Motivated Emotional Mind - Cognitive Embodied System](https://mlsanity.com/paper/2609.20437/) (2026)

## Abstract (arXiv)

This paper presents Integrated Information Theory (IIT) 4.0. IIT aims to account for the properties of experience in physical (operational) terms. It identifies the essential properties of experience (axioms), infers the necessary and sufficient properties that its substrate must satisfy (postulates), and expresses them in mathematical terms. In principle, the postulates can be applied to any system of units in a state to determine whether it is conscious, to what degree, and in what way. IIT offers a parsimonious explanation of empirical evidence, makes testable predictions, and permits inferences and extrapolations. IIT 4.0 incorporates several developments of the past ten years, including a more accurate translation of axioms into postulates and mathematical expressions, the introduction of a unique measure of intrinsic information that is consistent with the postulates, and an explicit assessment of causal relations. By fully unfolding a system's irreducible cause-effect power, the distinctions and relations specified by a substrate can account for the quality of experience.