Bohr complementarity in memory retrieval

Abstract

We comment on the use of the mathematical formalism of Quantum Mechanics in the analysis of the documented subadditivity phenomenon in human episodic memory. This approach was first proposed by Brainerd et al. in Brainerd et al. (2013). The subadditivity of probability in focus arises as a violation of the disjunction rule of Boolean algebra. This phenomenon is viewed as a consequence of the co-existence of two types of memory traces: verbatim and gist. Instead of assuming that verbatim and gist trace can combine into a coherent memory state of superposition as is done in the QEM model, we propose to model gist and verbatim traces as Bohr complementary properties of memory. In mathematical terms, we represent the two types of memory as alternative bases of one and the same Hilbert Space. We argue that, in contrast with the QEM model, our model appeals to the one essential distinction between classical and quantum models of reality namely the existence of incompatible but complementary properties of a system. This feature is also at the heart of the quantum cognition approach to mental phenomena. We sketch an experiment that could separate the two models. We next test our model with data from the same word list experiment as the one used by Brainerd et al. While our model entails significantly less degrees of freedom it yields a good fit to the experimental data.