Context can influence the number of responses elicited by a discrete, appetitive conditioned stimulus (CS) but can context control when a CS elicits a response? To test this fundamental question, we gave male, Long-Evans rats Pavlovian conditioning sessions in which the same auditory conditioned stimulus (CS, 30 s, 15 trials/session) was presented in 2 different physical contexts on alternating days, according to a within-subjects design. In one context, called the early context, alcohol (15% ethanol, 0.2 ml/trial) was delivered from the onset of the 5th second until the termination of the 10th second of the 30 s CS. In the second late context, alcohol was delivered from the onset of the 25th second until the termination of the 30th second of the same CS. In a comparison of the last session of training, the probability of making a conditioned response during the first four seconds of the CS was significantly higher in the early context than in the late context. This result shows that context can signal when an unconditioned stimulus occurs in relation to a CS and highlights a role for context in controlling precisely timed alcohol-seeking responses.

中文翻译：

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上下文控制对酒精预测条件刺激的反应时间

上下文可以影响由离散的、食欲条件刺激 (CS) 引起的反应数量，但是当 CS 引起反应时，上下文可以控制吗？为了测试这个基本问题，我们对雄性 Long-Evans 大鼠进行巴甫洛夫条件反射训练，其中相同的听觉条件刺激（CS，30 秒，15 次试验/训练）在交替的日子里在 2 个不同的物理环境中呈现。 ——学科设计。在一种称为早期背景的情况下，酒精（15% 乙醇，0.2 毫升/次）从第 5 秒开始直到 30 秒 CS 的第 10 秒结束。在第二个晚期上下文中，酒精从第 25 秒的开始到同一 CS 的第 30 秒结束。对比上一期训练，在 CS 的前四秒内做出条件反应的概率在早期上下文中明显高于晚期上下文。该结果表明，当与 CS 相关的无条件刺激发生时，上下文可以发出信号，并突出了上下文在控制精确定时的寻求酒精反应中的作用。