A concrete electronic-circuit example shows that Integrated Information Theory (IIT) is simultaneously falsified at one level of analysis (finite-state automaton) and unfalsifiable at another (combinatorial state automaton). The authors argue that to avoid being unfalsifiable or already falsified, scientific theories of consciousness must be invariant under changes that leave the inference procedure fixed at a given level in a computational hierarchy.
A mathematical analysis shows that Integrated Information Theory (IIT), a leading theory of consciousness, relies on a measure called Φ that can differ between two physically isomorphic systems—systems identical in size, function, and causal structure—solely due to a permutation of the binary labels representing internal functional states. This means a system with Φ > 0 (deemed conscious) and an isomorphic system with Φ = 0 (a philosophical zombie) can be mathematically identical except for arbitrary labeling. The finding challenges IIT's assumption that feedback is necessary for consciousness and suggests any quantitative theory of consciousness should be invariant under such isomorphisms to avoid epistemological problems.