“…The ambiguity, however, should have been reduced by the fact that the observers were familiar with the demonstrators and thus more likely to be sensitive to their We find the low level of contingency knowledge and its impact on conditioning measures interesting (as it highlights the role of the observer's attention and the observational stimulus quality), but not surprising, given that the role of contingency knowledge has been described for various conditioning protocols and conditioning measures (e.g. Baeuchl et al, 2019;Tabbert et al, 2006Tabbert et al, , 2011Weidemann et al, 2016). While skin conductance response has been reported as a measure reflecting contingency learning (Sevenster et al, 2014), a potentiation of the acoustic startle reflex has been claimed to be a specific index of fear acquisition, not requiring contingency awareness (Hamm & Vaitl, 1996;Hamm & Weike, 2005) and generally considered to be more valence-specific and less dependent on attention (Lang et al, 1990; although see Mertens & De Houwer, 2016).…”