Everything in its right place: a case report of reduplicative paramnesia with therapeutic and theoretical considerations.

Introductions: Reduplicative paramnesia (RP) is a rare and poorly understood phenomenon in which a person believes the place they are in has been replicated and exists in two places at once. There is minimal extant theoretical work addressing possible cognitive mechanisms subtending RP. Method: We present a new case of RP and discuss the therapeutic and theoretical implications of this case for the management and understanding of this phenomenon. Using the hypothetico-deductive approach to a neuropsychological case, we examine the phenomenon in the light of one and two-factor approaches to understanding the genesis of delusions. Results: The individual discussed in this case showed some evidence of relatively efficient incorporation of new evidence (belief updating) despite concurrently maintaining a delusional belief system. Conclusion: This case raises novel challenges for the two-factor account of neurological delusions.