Wheeler Daniel S, Miller Ralph R
Department of Psychology, Binghamton University, State University of New York, Binghamton, NY 13902-6000, USA.
J Exp Psychol Anim Behav Process. 2007 Jul;33(3):349-59. doi: 10.1037/0097-7403.33.3.349.
Preexposure of a cue without an outcome (X-) prior to compound pairings with the outcome (XZ-->O) can reduce overshadowing of a target cue (Z). Moreover, pairing a cue with an outcome (X-->O) before compound training can enhance its ability to compete with another cue (i.e., blocking). Four experiments were conducted in a conditioned bar-press suppression preparation with rats to determine whether spacing of the X- or X-->O trials would differentially affect reduced overshadowing and blocking. Experiment 1a showed that reduced overshadowing was larger with massed trials than with spaced trials. Experiment 1b found that blocking was larger with spaced trials than with massed trials. Experiments 2a and 2b indicated that these effects of trial spacing were both mediated by the associative status of the context at test. The results are interpreted in the framework of contemporary learning theories.
在与结果（XZ→O）进行复合配对之前，先对无结果的线索（X-）进行预暴露，可以减少目标线索（Z）的遮蔽效应。此外，在复合训练之前将线索与结果（X→O）配对，可以增强其与另一个线索竞争的能力（即阻断）。在大鼠的条件性压杆抑制实验中进行了四项实验，以确定X-或X→O试验的间隔是否会对减少遮蔽效应和阻断产生不同影响。实验1a表明，集中试验的减少遮蔽效应比间隔试验更大。实验1b发现，间隔试验的阻断效应比集中试验更大。实验2a和2b表明，试验间隔的这些效应均由测试时情境的联想状态介导。结果在当代学习理论的框架内进行了解释。
