In these experiments, the methodology of the original studies was followed as closely as possible. All studies involved contextual fear conditioning, followed one day later by brief (i.e., 2, 3, or 5 min) unreinforced re-exposure to the conditioned context and systemic injection of MDZ (1.5 or 3 mg/kg) or saline (SAL), and retention testing one day later.

↵¹Exact replication of Alfei et al. (2015) and Ferrer Monti et al. (2017).

↵²Exact replication of Stern et al. (2012).

↵³Exact replication of Espejo et al. (2016) and Ortiz et al. (2015).

The table indicates whether the experimenter and the lab in which the replication study was performed were the same as in the published, original study. The results show that the amnestic effect could not be replicated when the study was performed in a different lab or by another researcher, despite adherence to the experimental protocol of the original studies. These findings illustrate that the success of treatment may depend on subtle between-study differences, and the underlying causes of these failures to replicate remain unknown. Obtained power for our sample sizes, shown in the last column, was calculated using the smallest effect size (Hedges’ g) that was observed in the original studies (α = 0.05; d = 1.71 in Alfei et al., 2015; 1.31 in Stern et al., 2012; 2.91 in Espejo et al., 2016; see Table 2). A complete description of our replication attempts involving contextual fear can be found in Schroyens et al. (2019a,b). Appendix A (Tables A.1 and A.2) of Schroyens et al. (2019a) contains a detailed overview of experimental parameters for the conceptual and exact replication attempts, respectively. Experiment NSARG01 is described in Schroyens et al. (2019b).