A quantum circuit called a 'Schrödinger's dyad' could place a minimal system into a superposition of states that differ in their associated conscious states, as described by Integrated Information Theory (IIT). The authors prove a structural constraint on standard collapse dynamics: if too few collapse operators govern the system, collapse rates cannot depend solely on qualitative differences between experiences. Avoiding this limitation requires many commuting operators, leading to a rapid proliferation of collapse terms even for simple systems. This complexity challenges claims that IIT-based collapse theories are especially experimentally tractable, and the difficulty extends to any theory distinguishing experiences using rich internal organization.
A quantum superposition of consciousness, as in Wigner's friend thought experiment, may be possible under integrated information theory (IIT). IIT treats consciousness as a measurable quantity, integrated information (Φ), so a system's consciousness equals its Φ. Using the latest IIT formalism (IIT4.0), the authors analyze the simplest nonzero-Φ system, a feedback dyad, and propose a circuit putting it into a superposition of states. This would correspond to a superposition of conscious states, called "Schrödinger's dyad." Either IIT is false or the dyad is conscious and easily superposed. The simplest consciousness-collapse model predicts this superposition is unstable, collapsing at a rate determined by differences between the superposed conscious states.