Giulio Tononi

University of Wisconsin-Madison

Integrated information Consciousness is intrinsic causal power, measured as integrated information

Position on AI consciousness

Tononi holds that most current AI is ruled out, because feedforward networks have near zero phi however capable they are, and that a simulation of a conscious brain would not be conscious, since the simulation's causal structure is the computer's rather than the thing simulated.

Giulio Tononi built the only major theory of consciousness that works backwards. Rather than examining brains and inferring what consciousness is, integrated information theory starts from properties experience is taken to have, that it exists, is structured, specific, unified and definite, and derives what a physical substrate must be like to have them. The quantity phi measures the result, how much a system’s cause and effect structure exceeds the sum of its parts.

The derivation has consequences most people find surprising and Tononi accepts. Feedforward networks have near zero phi however capable they are, so most current AI is ruled out. A simulation of a conscious brain would not be conscious, because the simulation’s causal structure is that of the computer rather than of the thing simulated. And simple systems with the right connectivity can score very high, which Scott Aaronson turned into the sharpest objection the theory has faced.

Tononi’s response to that objection is the most revealing thing about the theory. He did not dispute the mathematics. He accepted that the system in question is conscious and argued that our intuitions about which things have experience are unreliable. That is internally consistent, and it detaches the theory from independent checks, which is why phi remains uncomputable in practice and contested in principle.

Known for. Integrated information theory and the quantity phi

Coverage on this site

Research Papers and Preprints

Articles and Commentary

Before the Frameworks, There Were Shows How Classic Television Invented the AI Consciousness Problem March 2026

Related researchers

Giulio Tononi is listed with the other integrated information theorists, who hold that consciousness is intrinsic causal power, measured as integrated information. The theory family behind that position is set out in the index of consciousness theories. Every researcher covered on this site is indexed in the directory of consciousness researchers.