From the Phenomenology to the Mechanisms of Consciousness: Integrated Information Theory 3.0

Abstract

This paper presents Integrated Information Theory (IIT) of consciousness 3.0, which incorporates several advances over previous formulations. IIT starts from phenomenological axioms: information says that each experience is specific – it is what it is by how it differs from alternative experiences; integration says that it is unified – irreducible to non-interdependent components; exclusion says that it has unique borders and a particular spatio-temporal grain. These axioms are formalized into postulates that prescribe how physical mechanisms, such as neurons or logic gates, must be configured to generate experience (phenomenology). The postulates are used to define intrinsic information as “differences that make a difference” within a system, and integrated information as information specified by a whole that cannot be reduced to that specified by its parts. By applying the postulates both at the level of individual mechanisms and at the level of systems of mechanisms, IIT arrives at an identity: an experience is a maximally irreducible conceptual structure (MICS, a constellation of concepts in qualia space), and the set of elements that generates it constitutes a complex. According to IIT, a MICS specifies the quality of an experience and integrated information ΦMax its quantity. From the theory follow several results, including: a system of mechanisms may condense into a major complex and non-overlapping minor complexes; the concepts that specify the quality of an experience are always about the complex itself and relate only indirectly to the external environment; anatomical connectivity influences complexes and associated MICS; a complex can generate a MICS even if its elements are inactive; simple systems can be minimally conscious; complicated systems can be unconscious; there can be true “zombies” – unconscious feed-forward systems that are functionally equivalent to conscious complexes.

Signature of consciousness in the dynamics of resting-state brain activity

“…simulations of resting state brain activity (16,(21)(22)(23)(24), is that signatures of the conscious state lie in the dynamics of spontaneous brain activity. When averaged across a long time period, functional brain activity may appear similar in wakefulness and anesthesia (10,11,25), due to the existence of a backbone anatomical connectivity.…”

Probing the interface theory of perception: Reply to commentaries

“…ITP itself does not answer that question, because ITP is not committed to any particular ontology (e.g., physicalist, dualist, or idealist). If one augments ITP with, say, Seth Lloyd's ontology of qubits and gates, and then adopts, say, Tononi's (Oizumi, Albantakis, & Tononi, 2014) integrated information theory of consciousness, in which the amount and kind of conscious experience depends on the amount and kind of integrated information in a system, then one might get an answer about where perceptual icons are located that physicalists might find congenial, even though the language of spacetime and physical objects has been replaced by the language of qubits and quantum gates. We are not endorsing this ontology, but simply pointing to it as a possibility.…”

What Is Lost During Dreamless Sleep: The Relationship Between Neural Connectivity Patterns and Consciousness

“…Cortical connectivity is central in several theoretical approaches to consciousness (and cortical functioning in general); the most informative of these, in terms of making hypotheses regarding the neural characteristics of levels -as opposed to contents -of consciousness, has been the integrated information theory (IIT), developed by Tononi (2008) and recently revised by Oizumi, Albantakis, and Tononi (2014). According to IIT, consciousness is generated by interactions among brain regions, which must work together as an integrated system (integration), and the ability of the neurons to generate a repertoire of different states (information, or differentiation).…”

“…According to IIT, consciousness is generated by interactions among brain regions, which must work together as an integrated system (integration), and the ability of the neurons to generate a repertoire of different states (information, or differentiation). The thalamocortical system seems to fulfil these conditions, as it has many specialised regions that are also functionally and anatomically connected (Oizumi et al, 2014). The IIT predicts that a state of reduced consciousness (such as deep NREM sleep) should be marked by the brain's inability to integrate information -in other words, by a reduced ability of brain areas to communicate with each other (Tononi, 2008).…”