Response Rates Track the History of Reinforcement Times
Response Rates Track the History of Reinforcement Times
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DOI：
10.1037/a0023079
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发表时间：
2011-07-01
期刊：
影响因子：
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通讯作者：
Pincham, Hannah L.
中科院分区：
文献类型：
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作者：
Harris, Justin A.;Gharaei, Saba;Pincham, Hannah L.
当条件反射涉及条件刺激（CS）和非条件刺激（US）之间的一致的时间关系时，条件反射在试验内的表达在US相对于CS的通常时间达到峰值。在这里，我们检查的时间轮廓的反应在调节与变量CS-US间隔。我们条件刺激均匀分布或指数分布的随机CS-US间隔。在前一种情况下，指定范围内的每个CS-US间期的频率是均匀的，但US的瞬时概率（风险函数）在试验期间随着时间的推移而增加;对于后一种分布，短CS-US间期比长间期更频繁，但US的瞬时概率在试验期间的时间内是恒定的。我们报告说，在一个杂志的方法范例，大鼠的反应率保持稳定，随着时间的推移，在CS时，CS-US间隔均匀分布，而他们的反应率下降时，CS-US间隔呈指数分布。换句话说，CS期间的响应曲线与US时间的频率分布相匹配，而不是CS期间US的瞬时概率。这些结果是不一致的实时关联模型，预测关联强度跟踪的瞬间概率的美国，但可能提供支持的时间模型的条件反射，条件反射的反应是绑在记忆中的时间强化。
When conditioning involves a consistent temporal relationship between the conditioned stimulus (CS) and unconditioned stimulus (US), the expression of conditioned responses within a trial peaks at the usual time of the US relative to the CS. Here we examine the temporal profile of responses during conditioning with variable CS-US intervals. We conditioned stimuli with either uniformly distributed or exponentially distributed random CS-US intervals. In the former case, the frequency of each CS-US interval within a specified range is uniform but the momentary probability of the US (the hazard function) increases as time elapses during the trial; with the latter distribution, short CS-US intervals are more frequent than longer intervals, but the momentary probability of the US is constant across time within the trial. We report that, in a magazine approach paradigm, rats' response rates remained stable as time elapses during the CS when the CS-US intervals were uniformly distributed, whereas their response rates declined when the CS-US intervals were exponentially distributed. In other words, the profile of responding during the CS matched the frequency distribution of the US times, not the momentary probability of the US during the CS. These results are inconsistent with real-time associative models, which predict that associative strength tracks the momentary probability of the US, but may provide support for timing models of conditioning in which conditioned responding is tied to remembered times of reinforcement.