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.
The idea that consciousness causes the collapse of the quantum wave function, once taken seriously by physicists such as John von Neumann and Eugene Wigner but now widely dismissed, is revisited by combining integrated information theory—a mathematical theory of consciousness—with continuous spontaneous localization, an account of quantum collapse dynamics. Simple versions of this combined theory are falsified by the quantum Zeno effect, but more complex versions remain compatible with empirical evidence. Versions of the theory can in principle be tested by experiments with quantum computers. The conclusion is not that consciousness-collapse interpretations are clearly correct, but that there is a research program here worth exploring.