Wilkinson G M, Lovibond P F, Siddle D A, Bond N
School of Psychology, University of New South Wales, Sydney, Australia.
Biol Psychol. 1989 Apr;28(2):89-104. doi: 10.1016/0301-0511(89)90092-6.
Safety signal learning in human subjects was investigated using a conditioned inhibition procedure with a shock unconditioned stimulus (US). The conditioned stimulus (CS) duration, and thus the CS-US interval, varied randomly from 20 to 50 s. Conditioning was assessed by change in tonic skin conductance level (SCL). Experiment 1 demonstrated reliable learning of a conditioned inhibition (A+/AB-) discrimination, in terms of both self-reported shock expectancy and change in SCL, in subjects who were able to report correctly the stimulus contingency. There was, however, no evidence of transfer of inhibitory properties from the safety signal B to a separately trained excitor. Experiment 2 compared two groups in which the safety signal was either fear-relevant (picture of snake or spider) or fear-irrelevant (flower or mushroom). As in previous research, there was no effect of fear-relevance on safety-signal learning. The results are discussed in terms of preparedness theory and excitatory conditioning with fear-relevant stimuli.
利用带有电击无条件刺激（US）的条件性抑制程序，对人类受试者的安全信号学习进行了研究。条件刺激（CS）的持续时间，以及CS-US间隔，在20到50秒之间随机变化。通过静息皮肤电导水平（SCL）的变化来评估条件作用。实验1表明，在能够正确报告刺激偶然性的受试者中，就自我报告的电击预期和SCL的变化而言，对条件性抑制（A+/AB-）辨别有可靠的学习。然而，没有证据表明抑制特性从安全信号B转移到了单独训练的兴奋刺激物上。实验2比较了两组，其中安全信号要么与恐惧相关（蛇或蜘蛛的图片），要么与恐惧无关（花或蘑菇）。与之前的研究一样，恐惧相关性对安全信号学习没有影响。根据准备理论以及与恐惧相关刺激的兴奋性条件作用对结果进行了讨论。
