Brennan J F
Dev Psychobiol. 1979 Jan;12(1):27-37. doi: 10.1002/dev.420120104.
Three experiments examined age-related differences in extinction of active avoidance in rats through manipulation of the stimulus context. In Experiment I, 36 weanlings and 36 adults acquired comparable avoidance levels to a tonal conditioned stimulus (CS), and novel stimuli consisting of either the presence of a naive rat or a light were presented during 2 tests in extinction. Results indicated more pronounced disruption of extinction in the pups, compared to adults, with the animate novel stimulus having the greater effect. Eighteen pups of 22 days of age and 18 adults in Experiment II were trained to avoid shock with a CS consisting of simultaneous tone and light onset. During extinction responses did not terminate 1 of the CS elements, but rather produced continuation of either the tone or light for an additional 5 sec. Continuation of the tonal element resulted in greater disruption of extinction trials than the light in the adults, although the pups had faster, but nondifferential, extinction rates. A 3rd experiment presented 36 pups and adults with either 0-, 5-, or 10-sec delays of tonal CS reactivation after extinction responses. Both 5- and 10-sec delays resulted in increased numbers of extinction trials in the adults, but the pups failed to respond differentially to any of the delay intervals. Results of all of the experiments were considered in light of species-specific behaviors in avoidance extinction relative to environmental and associative saliencies between ages.
三项实验通过对刺激情境的操控，研究了大鼠主动回避消退中与年龄相关的差异。在实验一中，36只幼鼠和36只成年鼠对音调条件刺激（CS）获得了相当的回避水平，并且在两次消退测试期间呈现了由一只未接触过实验的大鼠出现或一道光组成的新刺激。结果表明，与成年鼠相比，幼鼠的消退受到更明显的干扰，有生命的新刺激产生的影响更大。实验二中，18只22日龄的幼鼠和18只成年鼠被训练通过由音调与光同时出现组成的CS来避免电击。在消退过程中，反应并未终止CS的一个元素，而是使音调或光再持续5秒。对于成年鼠，音调元素的持续导致消退试验受到的干扰比光更大，尽管幼鼠的消退速度更快，但没有差异。第三个实验在消退反应后向36只幼鼠和成年鼠呈现音调CS重新激活的0秒、5秒或10秒延迟。5秒和10秒的延迟都导致成年鼠的消退试验次数增加，但幼鼠对任何延迟间隔都没有差异反应。所有实验的结果都根据与年龄相关的环境和联想显著性在回避消退中的物种特异性行为进行了考量。
