  Could there be a quantum superposition of consciousness, as in the Wigner's
friend thought experiment? The integrated information theory (IIT) of
consciousness has turned this into a well-defined question. According to IIT,
consciousness is a measurable physical quantity given by integrated information
($\Phi$), such that the amount of consciousness in a system corresponds to its
amount of $\Phi$. We use the most recent IIT formalism (IIT4.0) to analyze the
simplest non-zero $\Phi$ system known as a feedback dyad. We then propose a
circuit that puts the dyad into a superposition of states which, according to
IIT, would correspond to a superposition of conscious states. We refer to this
as "Schr\"odinger's dyad". We therefore show that either IIT is false or the
simple dyad is conscious and can easily be put into a superposition of
conscious states. We then identify the simplest possible consciousness-collapse
model, which predicts that this superposition is unstable and collapses at a
rate determined by a measure of difference between the superposed conscious
states. Our analysis will enable us to make a number of key observations about
the general structure of integrated information theory (IIT2.0, IIT3.0, IIT4.0,
and QIIT) and the general structure of consciousness-collapse models.
