Halliday R, Gregory K, Naylor H, Callaway E, Yano L
University of California, San Francisco.
Acta Psychol (Amst). 1990 Feb;73(1):35-54. doi: 10.1016/0001-6918(90)90057-m.
Several studies have shown that d-amphetamine (DAMP) speeds mean reaction time (RT). However, the use of mean RT may obscure important aspects of the drug response. Therefore we applied the Poisson-Erlang (PE) stochastic model of choice reaction time proposed by Pieters (1985) to the RT distribution. This model proposes that the RT distribution is generated by two states: Processing (P) and Distraction (D). RT represents the sum of the time spent in each of these states. P is the time taken to complete a set of cognitive operations which are required to give a correct response. D represents the time taken by all other activities. RTs were collected using a task (SERS) in which stimulus and response complexity each had two levels, easy and hard. Subjects were tested pre- and postdrug. Drug conditions were: placebo, 10 mg d-amphetamine (DAMP), 4 mg of the dopamine agonist, pimozide, and a combination of DAMP and pimozide (COMBO). Parameters of the model were derived using methods described by Pieters. Four measures were analyzed: Processing Time (PT); Mean Time per distraction (XTD); Distraction Rate (DR); and Total Distraction Time per trial (TDT). Mean RT is also presented. Analyses of the effects of task conditions on the parameters of the model were made using the predrug sessions. Mean RT was increased by both stimulus and response complexities as was PT. TDT was increased by the task conditions. The PE measures did not change over days. DAMP speeded mean RT. However, this effect did not interact with the task factors. DAMP speeded processing and reduced distraction. Processing was speeded only in the hard response condition, distraction time was reduced only in the easy response condition. The results indicate that the PE model can be successfully applied to fast RT tasks. More importantly, the parameters of the model revealed important pharmacological effects that were not apparent in mean RT. DAMP speeds cognitive operations related to motor preparation and reduces the effects of distraction. Consistent with past studies there are no indications that DAMP interacted with stimulus processing. The distraction effect appears to be mediated by an increase in the rate of distraction and a decrease in the average time of these distractions.
多项研究表明，右旋苯丙胺（DAMP）可加快平均反应时间（RT）。然而，使用平均反应时间可能会掩盖药物反应的重要方面。因此，我们将皮特斯（1985年）提出的选择反应时间的泊松 - 埃尔朗（PE）随机模型应用于反应时间分布。该模型提出，反应时间分布由两种状态产生：处理（P）和干扰（D）。反应时间代表在每种状态下所花费时间的总和。P是完成一组给出正确反应所需认知操作所花费的时间。D代表所有其他活动所花费的时间。使用一种任务（SERS）收集反应时间，其中刺激和反应复杂性各有两个水平，即简单和困难。在用药前和用药后对受试者进行测试。药物条件为：安慰剂、10毫克右旋苯丙胺（DAMP）、4毫克多巴胺激动剂匹莫齐特以及DAMP和匹莫齐特的组合（COMBO）。模型参数使用皮特斯描述的方法得出。分析了四项指标：处理时间（PT）；每次干扰的平均时间（XTD）；干扰率（DR）；以及每次试验的总干扰时间（TDT）。还给出了平均反应时间。使用用药前阶段的数据对任务条件对模型参数的影响进行了分析。平均反应时间以及处理时间随着刺激和反应复杂性的增加而增加。总干扰时间因任务条件而增加。PE指标在不同天数间没有变化。DAMP加快了平均反应时间。然而，这种效应与任务因素没有相互作用。DAMP加快了处理速度并减少了干扰。仅在困难反应条件下处理速度加快，仅在简单反应条件下干扰时间减少。结果表明，PE模型可以成功应用于快速反应时间任务。更重要的是，模型参数揭示了平均反应时间中不明显的重要药理学效应。DAMP加快了与运动准备相关的认知操作并减少了干扰的影响。与过去的研究一致，没有迹象表明DAMP与刺激处理相互作用。干扰效应似乎是由干扰率的增加和这些干扰的平均时间的减少介导的。
