Romaniuk C B, Williams D A
Department of Psychology, University of Winnipeg, Manitoba, Canada.
J Exp Psychol Anim Behav Process. 2000 Oct;26(4):454-61. doi: 10.1037//0097-7403.26.4.454.
Five conditioned suppression experiments examined the extent to which an appetitively motivated lever-press response can be punished by different components of a backward conditioned stimulus (CS). Using a 0-s unconditioned stimulus (US)-CS interval, Experiments 1 and 2 showed that the initial 3 s of a normally 30-s backward CS served as a more effective punisher than the CS as a whole. Experiment 3 found no such effect if the US-CS interval were 3 s rather than 0 s. Experiments 4A and 4B found that if the US-CS interval were 0 s, the initial part of the backward CS acquired excitatory properties although the CS as a whole passed a summation test for conditioned inhibition. By contrast, the 3-s US-CS interval supported inhibitory conditioning across the whole duration of the backward CS. Taken together, these findings support a modified version of Wagner's sometimes opponent process model, which suggests that different components of a backward CS become either excitatory or inhibitory depending on the components' temporal proximity to the US.
五项条件性抑制实验考察了由正向条件刺激（CS）的不同成分对受食欲驱动的杠杆按压反应进行惩罚的程度。实验采用0秒的非条件刺激（US）-CS间隔，实验1和2表明，通常为30秒的正向CS的最初3秒作为惩罚比整个CS更有效。如果US-CS间隔为3秒而非0秒，实验3未发现此效应。实验4A和4B发现，如果US-CS间隔为0秒，正向CS的起始部分获得了兴奋性特性，尽管整个CS通过了条件性抑制的总和测试。相比之下，3秒的US-CS间隔在正向CS的整个持续时间内都支持抑制性条件作用。综上所述，这些发现支持了瓦格纳有时的对立过程模型的修正版本，该模型表明正向CS的不同成分根据其与US的时间接近程度而变得具有兴奋性或抑制性。
