Barnet R C, Grahame N J, Miller R R
Department of Psychology, State University of New York, Binghamton 13902-6000.
J Exp Psychol Anim Behav Process. 1993 Jul;19(3):215-30.
Responding to a conditioned stimulus (CS) is impaired if the CS is trained in the presence of excitatory local context cues. Four lick suppression experiments with rats explored whether this local context effect arises from the influence of excitatory cues that precede or that follow a reinforced target CS. Pretrained nontarget stimuli served as local context cues that occurred (a) immediately before and after the target CS trial, (b) immediately before or after the target CS trial, or (c) only before or after the target CS trial with varying intervals between the nontarget stimulus and target CS. Results indicated similar control over responding to the target CS by the preceding and following nontarget cues. This outcome implies a symmetrical window of memory integration (local time horizon) for a Pavlovian CS. Possible mechanisms underlying the detrimental effect of embedding a CS in an excitatory local context are discussed.
如果条件刺激（CS）是在兴奋性局部情境线索存在的情况下进行训练的，那么对该条件刺激的反应就会受损。用大鼠进行的四项舔舐抑制实验探究了这种局部情境效应是否源于强化目标条件刺激之前或之后的兴奋性线索的影响。预先训练的非目标刺激作为局部情境线索，它们出现的情况如下：（a）在目标条件刺激试验之前和之后立即出现；（b）仅在目标条件刺激试验之前或之后立即出现；（c）仅在目标条件刺激试验之前或之后出现，且非目标刺激与目标条件刺激之间的间隔时间各不相同。结果表明，之前和之后的非目标线索对目标条件刺激反应的控制作用相似。这一结果意味着巴甫洛夫条件刺激存在一个对称的记忆整合窗口（局部时间范围）。文中还讨论了将条件刺激置于兴奋性局部情境中产生有害影响的潜在机制。
