Integrated Information Theory

Integrated information theory (IIT) attempts to provide a framework capable of explaining why some physical systems (such as human brains) are conscious, why they feel the particular way they do in particular states (e.g. why our visual field appears extended when we gaze out at the night sky), and what it would take for other physical systems to be conscious (Are other animals conscious? Might the whole Universe be?). https://en.wikipedia.org/wiki/Integrated_information_theory Espoused by Erik Hoel.

IIT was proposed by neuroscientist Giulio Tononi in 2004. The latest version of the theory, labeled IIT 3.0, was published in 2014. However, the theory is still in development

Rather than try to start from physical principles and arrive at consciousness, IIT "starts with consciousness" (accepts the existence of our own consciousness as certain) and reasons about the properties that a postulated physical substrate would need to have in order to account for it.

IIT moves from phenomenology to mechanism by attempting to identify the essential properties of conscious experience (dubbed "axioms") and, from there, the essential properties of conscious physical systems (dubbed "postulates").

Axioms: essential properties of experience

the most recent and complete statement of the axioms is as follows:

Intrinsic existence: Consciousness exists:

Composition: Consciousness is structured: each experience is composed of multiple phenomenological distinctions

nformation: Consciousness is specific:

Integration: Consciousness is unified: each experience is irreducible

Exclusion: Consciousness is definite, in content and spatio-temporal grain

Postulates: properties required of the physical substrate

Intrinsic existence: To account for the intrinsic existence of experience, a system constituted of elements in a state must exist intrinsically (be actual):

Composition: The system must be structured

Information: The system must specify a that is the particular way it is: a specific set of specific —thereby differing from other possible ones (differentiation).

Integration: The cause-effect structure specified by the system must be unified

Exclusion: The cause-effect structure specified by the system must be definite

Mathematics: formalization of the postulates

For a visual illustration of the algorithm, see the supplementary material of the paper describing the PyPhi toolbox.

Neuroscientist Christof Koch, who has helped to develop later versions of the theory, has called IIT "the only really promising fundamental theory of consciousness". Technologist and Koch's ex-student Virgil Griffith says "IIT is currently the leading theory of consciousness." However, his answer to whether IIT is exactly the right theory is ‘Probably not’.

Philosopher David Chalmers, famous for the idea of the hard problem of consciousness, has expressed some enthusiasm about IIT. According to Chalmers, IIT is a development in the right direction, whether or not it is correct.

Neuroscientists Björn Merker, David Rudrauf and Philosopher Kenneth Williford co-authored a paper criticizing IIT on several grounds.

Neuroscientist Michael Graziano, proponent of the competing attention schema theory, rejects IIT as pseudoscience. He claims IIT is a "magicalist theory" that has "no chance of scientific success or understanding".

A peer-reviewed commentary by 58 scholars involved in the scientific study of consciousness rejects these conclusions about logic gates as “mysterious and unfalsifiable claims” that should be distinguished from “empirically productive hypotheses”.

Influential philosopher John Searle has given a critique of theory saying "The theory implies panpsychism" and "The problem with panpsychism is not that it is false; it does not get up to the level of being false. It is strictly speaking meaningless because no clear notion has been given to the claim."