Schweitzer L, Green L
Pavlov J Biol Sci. 1982 Apr-Jun;17(2):62-8.
The ability of rats to reevaluate previously presented information in light of subsequently provided information was evaluated using a CER (conditioned emotional response) procedure. In Experiment 1, rats suppressed responding to a compound light + tone stimulus that was repeatedly paired with shock. Groups of rats were then presented with only one element of the compound (the tone), either presented alone or paired with shock, for 15 days. During this 15-day period, two control groups received trials with the shock alone or neither stimulus nor shock. All of the rats were then tested with the other element of the compound (the light). Rats that had received the tone paired with shock during the intervening training continued to suppress to the light, whereas rats that had received the tone alone showed rapid extinction of the CER to light. The control groups showed that this effect was not due to the number of shock presentations received. A subsequent experiment also demonstrated that these results were not due to nonspecific stimulus effects. Apparently, a subsequent change in the associative strength of one element results in a similar change to the other element of a previously established compound stimulus.
利用条件性情绪反应（CER）程序评估大鼠根据随后提供的信息重新评估先前呈现信息的能力。在实验1中，大鼠对与电击反复配对的复合光+音调刺激的反应受到抑制。然后将大鼠分组，只呈现复合刺激中的一个元素（音调），单独呈现或与电击配对，持续15天。在这15天期间，两个对照组分别接受单独电击试验或既无刺激也无电击的试验。然后对所有大鼠用复合刺激的另一个元素（光）进行测试。在中间训练期间接受与电击配对的音调的大鼠继续对光产生抑制反应，而只接受音调的大鼠对光的CER迅速消退。对照组表明，这种效应不是由于接受电击呈现的次数。随后的一项实验还表明，这些结果不是由于非特异性刺激效应。显然，一个元素的联想强度随后发生的变化会导致先前建立的复合刺激的另一个元素发生类似的变化。
