Backward evaluative conditioning has been shown to result in assimilative effects where backward conditional stimuli (CS) acquire the valence of the unconditional stimulus (US) or in contrast effects where backward CSs acquire valence opposite to the US. The current experiments were designed to assess whether the nature of evaluative backward conditioning varies as a function of US offset predictability, manipulated by varying US duration (fixed vs. variable), US-CS overlap (overlap vs. no overlap), and the presence of a forward conditioning CS. Experiment 1 employed backward conditioning only (US_Pleasant-CS₁; US_Unpleasant-CS₂) whereas Experiment 2 employed concurrent forward and backward conditioning (CS₃-US_Pleasant-CS₁; CS₄-US_Unpleasant-CS₂). Backward CS assimilation effects emerged in both experiments and did not differ as a function of US duration. Presence of a forward CS reduced backward conditioning, in particular in the no US-CS overlap condition. These findings provide no support for the notion that the nature of backward CS evaluations varies as a function of US offset predictability and indicate that concurrent forward conditioning can modulate the extent of backward conditioning and the effect of US-CS overlap.

研究表明，向后评估条件会导致同化效应，其中向后条件性刺激（CS）获得无条件刺激（US）的效价，或者与之相反，在向后条件性刺激（CS）获得与美国相反的效价的情况下。当前的实验旨在评估评估后向调节条件的性质是否随美国补偿的可预测性而变化，可以通过改变美国持续时间（固定vs.可变），US-CS重叠（重叠vs.不重叠）以及是否存在来控制前向CS的概念。实验1仅采用了反向条件（US _Pleasant -CS ₁； US_不愉快-CS ₂），而实验2采用了并发的正向和反向条件（CS _3）-US_宜人-CS ₁ ; CS _4-美国_不愉快-CS ₂）。在这两个实验中均出现了向后CS同化效果，并且没有随美国历时变化而变化。前向CS的存在减少了后向条件，特别是在没有US-CS重叠的情况下。这些发现不支持后向CS​​评估的性质随US偏移量可预测性而变化的观点，并表明同时进行的前向调节可以调节后向调节的程度和US-CS重叠的影响。