phi (integrated-information measure)

Compiled with AI assistance and selectively reviewed. Please consult the cited passages; the books remain the authoritative source. About this companion

Editorial synthesis · provisional

Definition

Phi is IIT’s proposed quantity of irreducible integration within a system’s causal organization. RB2 explains high values through differentiation combined with integration, contrasting them with decomposable, weakly interacting parts. The measure belongs to Tononi’s theoretical framework; this proposal supplies no newly calculated brain value, universal consciousness threshold or equivalence with functional-information rarity, data volume, emotional intensity or moral importance.

Explanation

The direct exposition introduces the symbol and contrasts integrated differentiated organization with relatively independent elements. A camera may handle many bits without the causal integration IIT requires. These comparisons convey the theory’s rationale; they are not local computations of Phi for the human brain, cerebellum or a particular artificial system.

Quantity is distinguished from quality: a causal structure’s particular organization is proposed to correspond to what an experience is like. RB2’s suggestion that arousal or attention might correlate with Phi is explicitly tentative language, not a demonstrated identity between stronger emotion and greater consciousness. No equation converting physiological intensity into Phi is invented.

The author records disputes over IIT and limits the identity claim. AB’s function-relative information discussion concerns a different measure and comparison space; lexical information overlap does not make it Phi. The proposal consequently retains a theoretical quantity with its own evidential burden and supplies neither a consciousness certificate nor a claim about ethical standing.

Scope and attribution

Keep the local theoretical exposition without inventing a version-independent formula, numeric threshold or measured result.

RB2 — The Real Book, Volume II: Becoming Is Being

The theoretical integration quantity differs from qualitative structure and tentative arousal correlations.

Occurrence locators: 28, 29, 30, 32, 33, 34, 38.

Background used in the editorial explanation

Named theories and mechanisms are distinguished from neighboring background, homonyms and the author’s own synthesis. Reproduced AI passages retain their separate voice.