“…Such inhibitory properties can be tested in a so-called summation test during which the CS+ and the CS-are presented contemporaneously as a compound (Christianson, et al, 2012;Laing & Harrison, 2021). Both animal (Cándido, González, & deBrugada, 2004;Myers & Davis, 2004;Richardson, Michener, Gann, North, & Schachtman, 2020) and human (Grillon & Ameli, 2001;Jovanovic, Kazama, Bachevalier, & Davis, 2012;Jovanovic, et al, 2005;Urcelay, Perelmuter, & Miller, 2008;Wendt, Neubert, Koenig, Thayer, & Hamm, 2015) studies demonstrated that potentiated startle responses elicited by the threat-predicting stimulus (CS+) can be attenuated or inhibited by the co-presence of a safetypredicting stimulus (CS-). Patients suffering from anxiety and stress-related disorders are less prone to identify and therefore to learn about safety (Boddez, Baeyens, Hermans, & Beckers, 2014;Jovanovic, Kazama, Bachevalier, & Davis, 2012;Lissek, et al, 2005).…”