As the first author of the paper I would like to straighten out that we did not manipulate or measure dopamine in this study (we conducted it in a Science Museum in Amsterdam, so we used purely behavioral measures). Also note that the notion of hippocampal dopamine underlying the effects of novelty comes from a robust literature in animals (mostly studies that do use pharmacological manipulations and neuroscientific measures). The formulation of "dopamine projecting to the hippocampus" dates back to an influential theory by Lisman & Grace 2005, which is why this wording is still prevalent in the literature.