Negative probabilities and counter-factual reasoning in quantum   cognition
  In this paper we discuss quantum-like decision-making experiments using negative probabilities. We do so by showing how the two-slit experiment, in the simplified version of the Mach-Zehnder interferometer, can be described by this formalism. We show that negative probabilities impose constraints to what types of counter-factual reasoning we can make with respect to (quantum) internal representations of the decision maker. 
J. Acacio de Barros and Gary Oas
physics.data-an quant-ph