In this paper, we discuss the implications for the determinateness and intersubjective consistency of conscious experience in two gedanken experiments from quantum mechanics (QM). In particular, we discuss Wigner's friend and the delayed choice quantum eraser experiment with a twist. These are both cases (experiments) where quantum phenomena, or at least allegedly possible quantum phenomena/experiments, and the content/efficacy of conscious experience seem to bear on one another. We discuss why these two cases raise concerns for the determinateness and intersubjective consistency of conscious experience. We outline a 4D-global constraint-based approach to explanation in general and for QM in particular that resolves any such concerns without having to invoke metaphysical quietism (as with pragmatic accounts of QM), objective collapse mechanisms or subjective collapse. In short, we provide an account of QM free from any concerns associated with either the standard formalism or relative-state formalism, an account that yields a single 4D block universe with determinate and intersubjectively consistent conscious experience for all conscious agents. Essentially, the mystery in both experiments is caused by a dynamical/causal view of QM, e.g., time-evolved states in Hilbert space, and as we show this mystery can be avoided by a spatiotemporal, constraint-based view of QM, e.g., path integral calculation of probability amplitudes using future boundary conditions. What will become clear is that rather than furiously seeking some way to make dubious deep connections between quantum physics and conscious experience, the kinds of 4D adynamical global constraints that are fundamental to both classical and quantum physics and the relationship between them, also constrain conscious experience. That is, physics properly understood, already is psychology.
Micheal David Silberstein