Blocking of conditioned suppression with 1 or 10 compound trials

It is generally agreed that the Kamin blocking effect provides a differential test of the model of classical conditioning proposed by Rescorla and Wagner (1972), on the one hand, and the models proposed by Mackintosh (1975) and Pearce and Hall (1980), on the other. Specifically, if the blocking effect occurs with 1 compound trial, Rescorla and Wagner are supported. Experiment 1 showed that prior training with one element of a simultaneous compound stimulus prevented the added element from becoming conditioned with 10 compound trials when compared with a nonpretrained (Kamin) control. A pseudoconditioning control, which received no compound training, showed substantial suppression only on the first trial. A contextual conditioning control, which received unsignaled shock prior to compound training, was suppressed, suggesting a failure of conditioning to contextual cues. Experiment 2 demonstrated 1-compound-trial blocking using a simultaneous presentation of the compound elements. The importance of this support for the Rescorla-Wagner model is discussed in the light of other supportive studies and those which support alternative models of classical conditioning.     

广枣提取液对小鼠免疫功能和运动耐力的影响

观察了广枣提取液对小鼠免疫功能、运动耐力的影响。结果表明：广枣提取液可明显增加小鼠耐缺氧时间，延长小鼠负重游泳时间，降低运动后小鼠血乳酸水平，显著提高其心肌组织中SOD活力；同时明显增加小鼠脾脏／体重、胸腺／体重比值，增强小鼠对巨噬细胞的吞噬能力．提高小鼠的细胞免疫、体液免疫功能。提示广枣提取液具有显著促进小鼠免疫功能及显著提高小鼠运动耐力的功效。     

Acquisition and extinction of conditioned nicotine analgesic tolerance

These studies demonstrated the acquisition and extinction of conditioned tolerance to the analgesic effect of nicotine in rats. In Experiment 1, distinctive environmental cues were either paired or unpaired with nicotine. Following acquisition, the paired group was more tolerant to nicotine than the unpaired and saline groups. Conditioned tolerance was extinguished in the paired group after placebo sessions in the distinctive environment. Experiment 2 examined whether the distinctive environment functioned as a CS or as an occasion setter for injection cues. After acquisition, exposure to the distinctive environment, with or without placebo injections, resulted in extinction. This demonstrates that the distinctive environment served as a CS, not as an occasion setter for injection cues.