Odum A L, Schaal D W
West Virginia University, USA.
J Exp Anal Behav. 2000 Sep;74(2):229-43. doi: 10.1901/jeab.2000.74-229.
Changes produced by drugs in response patterns under fixed-interval schedules of reinforcement have been interpreted to result from changes in temporal discrimination. To examine this possibility, this experiment determined the effects of morphine on the response patterning of 4 pigeons during a fixed-interval 1-min schedule of food delivery with interpolated temporal discrimination trials. Twenty of the 50 total intervals were interrupted by choice trials. Pecks to one key color produced food if the interval was interrupted after a short time (after 2 or 4.64 s). Pecks to another key color produced food if the interval was interrupted after a long time (after 24.99 or 58 s). Morphine (1.0 to 10.0 mg/kg) decreased the index of curvature (a measure of response patterning) during fixed intervals and accuracy during temporal discrimination trials. Accuracy was equally disrupted following short and long sample durations. Although morphine disrupted temporal discrimination in the context of a fixed-interval schedule, these effects are inconsistent with interpretations of the disruption of response patterning as a selective overestimation of elapsed time. The effects of morphine may be related to the effects of more conventional external stimuli on response patterning.
在固定间隔强化程序下，药物引起的反应模式变化被解释为是由时间辨别能力的变化所致。为检验这种可能性，本实验确定了吗啡对4只鸽子在固定间隔1分钟食物投递程序且穿插有时间辨别试验时反应模式的影响。总共50个间隔中有20个被选择试验打断。如果间隔在短时间（2秒或4.64秒后）被打断，啄一种颜色的按键会得到食物。如果间隔在长时间（24.99秒或58秒后）被打断，啄另一种颜色的按键会得到食物。吗啡（1.0至10.0毫克/千克）在固定间隔期间降低了曲率指数（一种反应模式的度量），并降低了时间辨别试验中的准确性。短和长样本持续时间后准确性均受到同等程度的干扰。尽管吗啡在固定间隔程序背景下扰乱了时间辨别，但这些效应与将反应模式扰乱解释为对经过时间的选择性高估不一致。吗啡的效应可能与更传统的外部刺激对反应模式的影响有关。
