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

Larissa Albantakis; Leonardo Barbosa; Graham Findlay; Matteo Grasso; Andrew M Haun; William Marshall; William G P Mayner; Alireza Zaeemzadeh; Melanie Boly; Bjørn E Juel; Shuntaro Sasai; Keiko Fujii; Isaac David; Jeremiah Hendren; Jonathan P Lang; Giulio Tononi

doi:10.1371/journal.pcbi.1011465

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

PLoS Comput Biol. 2023 Oct 17;19(10):e1011465. doi: 10.1371/journal.pcbi.1011465. eCollection 2023 Oct.

Authors

Larissa Albantakis¹, Leonardo Barbosa^{1

2}, Graham Findlay^{1

3}, Matteo Grasso¹, Andrew M Haun¹, William Marshall^{1

4}, William G P Mayner^{1

3}, Alireza Zaeemzadeh¹, Melanie Boly^{1

5}, Bjørn E Juel^{1

6}, Shuntaro Sasai^{1

7}, Keiko Fujii¹, Isaac David¹, Jeremiah Hendren^{1

8}, Jonathan P Lang¹, Giulio Tononi¹

Affiliations

¹ Department of Psychiatry, University of Wisconsin, Madison, Wisconsin, United States of America.
² Fralin Biomedical Research Institute at VTC, Virginia Tech, Roanoke, Virginia, United States of America.
³ Neuroscience Training Program, University of Wisconsin, Madison, Wisconsin, United States of America.
⁴ Department of Mathematics and Statistics, Brock University, St. Catharines, Ontario, Canada.
⁵ Department of Neurology, University of Wisconsin, Madison, Wisconsin, United States of America.
⁶ Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
⁷ Araya Inc., Tokyo, Japan.
⁸ Graduate School Language & Literature, Ludwig Maximilian University of Munich, Munich, Germany.

Abstract

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 concerning both the presence and the quality of experience, and permits inferences and extrapolations. IIT 4.0 incorporates several developments of the past ten years, including a more accurate formulation of the axioms as 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.

Copyright: © 2023 Albantakis et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brain*
Consciousness
Information Theory*
Models, Neurological

Grants and funding

This project was made possible through the support of a grant from Templeton World Charity Foundation (TWCF0216, G.T.). In addition, this research was supported by the David P White Chair in Sleep Medicine at the University of Wisconsin-Madison, by the Tiny Blue Dot Foundation (UW 133AAG3451; G.T.), and by the Natural Science and Engineering Research Council of Canada (NSERC; RGPIN-2019-05418; W.M.). L.A. also acknowledges the support of a grant from the Templeton World Charity Foundation (TWCF-2020-20526, L.A.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.