Leung Hiu Tin, Reeks Leanne M, Westbrook R Frederick
School of Psychology, University of New South Wales, Sydney, Australia.
J Exp Psychol Anim Behav Process. 2012 Oct;38(4):394-406. doi: 10.1037/a0030201.
A series of experiments used rats to compare and contrast the effects of subjecting an already extinguished target conditioned stimulus (CS) to additional extinction in compound with either another extinguished or a nonextinguished CS. Exposure to either compound restored responding and their extinction deepened the loss of fear responses (freezing) to the target relative to a CS given equivalent extinction in isolation. This deepening was greater to the target extinguished in compound with the nonextinguished than with the extinguished CS. Summation tests showed that the target suppressed responding to an excitor or an excitatory context when it had been extinguished in compound with a nonextinguished but not with an extinguished CS. The results were interpreted to mean that additional extinction in compound with another extinguished CS resulted in the target acquiring the additional inhibition required to more fully oppose its original excitation. In contrast, additional extinction in compound with a nonextinguished CS resulted in the target acquiring not only the additional inhibition required to oppose its original excitation but also that of the nonextinguished CS, thereby converting the target into a net inhibitor.
一系列实验使用大鼠来比较和对比，使已经消退的目标条件刺激（CS）与另一个已消退或未消退的CS复合进行额外消退的效果。暴露于任何一种复合刺激都会恢复反应，并且相对于单独给予同等消退的CS，它们的消退加深了对目标的恐惧反应（僵住）的丧失。与未消退的CS复合消退的目标相比，与已消退的CS复合消退的目标，这种加深程度更大。总和测试表明，当目标与未消退的CS而非已消退的CS复合消退时，它会抑制对刺激物或兴奋性情境的反应。结果被解释为意味着，与另一个已消退的CS复合进行额外消退，导致目标获得了更充分对抗其原始兴奋所需的额外抑制。相比之下，与未消退的CS复合进行额外消退，导致目标不仅获得了对抗其原始兴奋所需的额外抑制，还获得了未消退的CS的额外抑制，从而使目标转变为净抑制剂。
