Urushihara Kouji, Miller Ralph R
Department of Psychology, Health Sciences University of Hokkaido.
J Exp Psychol Anim Behav Process. 2010 Apr;36(2):281-95. doi: 10.1037/a0016773.
Three lick suppression experiments with rats investigated backward blocking in first-order conditioning. As has been suggested in prior studies, the experiments demonstrated that backward blocking is difficult to obtain in conventional first-order conditioning situations. However, the authors demonstrate here that backward blocking is observed in first-order conditioning if the target cue's behavioral control is weak at the time of elemental training of the blocking cue. The target cue's behavioral control was weakened through forward blocking of the target cue by a third cue (Experiment 1), conducting compound and elemental training with backward temporal relationships to the unconditioned stimulus (Experiment 2), and extinguishing the target cue following compound training (Experiment 3). The results of these experiments suggest that weak control of behavior by the blocked cue at the time of elemental training of the blocking cue is a critical determinant of whether blocking can be observed. Prior failures to detect backward blocking in first-order conditioning are seemingly due to a difficulty in decreasing the response-eliciting potential of a cue by indirect means such as associative inflation of a competing cue.
三项针对大鼠的舔舐抑制实验研究了一阶条件反射中的逆向阻断现象。正如先前研究所表明的那样，这些实验证明在传统的一阶条件反射情境中很难实现逆向阻断。然而，作者在此证明，如果在对阻断线索进行基本训练时目标线索的行为控制较弱，那么在一阶条件反射中就能观察到逆向阻断。通过用第三个线索对目标线索进行前向阻断（实验1）、与无条件刺激建立反向时间关系进行复合和基本训练（实验2）以及在复合训练后消除目标线索（实验3），目标线索的行为控制被削弱。这些实验结果表明，在对阻断线索进行基本训练时，被阻断线索对行为的弱控制是能否观察到阻断的关键决定因素。之前在一阶条件反射中未能检测到逆向阻断，似乎是由于难以通过诸如竞争线索的联想膨胀等间接手段来降低线索引发反应的潜力。
