Consciousness and the Wigner's friend problem
arXiv Preprint Archive February 18, 2004 Bernard d'Espagnat
Decoherence theory is widely seen as a major advance toward solving the quantum measurement problem, but its consistency is challenged when a sentient being observes the outcome. The Broglie-Bohm model suggests that even simple systems might possess a form of proto-consciousness, though their internal states of consciousness are not predictive. As systems grow larger, decoherence makes these internal states increasingly predictive, so for macroscopic systems they can be identified with the predictive states of consciousness used in observational predictions. Extending this idea to standard quantum mechanics leads to two conceptually distinct solutions, both relying on generalized internal states of consciousness that may be non-predictive.