Brown R G, Jahanshahi M, Marsden C D
Medical Research Council Human Movement and Balance Unit, National Hospital for Neurology and Neurosurgery, London, UK.
Brain. 1993 Aug;116 ( Pt 4):869-85. doi: 10.1093/brain/116.4.869.
Reaction time paradigms provide a set of methods for assessing aspects of the planning and execution of voluntary movements in Parkinson's disease. Attention has focused mainly on the issue of programming of responses, employing a combination of simple reaction time (SRT) and choice reaction time (CRT) paradigms. The first part of the present study replicated an earlier finding in which patients showed a disproportionate slowing in CRT compared with SRT. The main aim of the study was to investigate the possible role of response choice, a key stage prior to motor programming in this CRT deficit. Two factors were manipulated: (i) response uncertainty and (ii) stimulus-response compatibility. The patients showed a normal increase in reaction time with increasing uncertainty in the compatible conditions, and a normal response to stimulus-response compatibility in the two-choice task. However, the two groups showed qualitatively different patterns of interaction between the two experimental factors, with only the patients showing a disproportionate slowing with incompatible stimulus-response relationships in the four-choice task. The data were interpreted in terms of Hasbroucq et al.'s (1990) list-rule model of stimulus-response compatibility effects, which suggested that the patients and controls were using different strategies for dealing with incompatible stimulus-response relationships. The use of different strategies makes it impossible to determine whether or not the processing of the patients is impaired in Parkinson's disease, although further research is suggested to clarify the question. However, the present data suggest that any impairment in response choice is unlikely to contribute to the slowing in CRT in Parkinson's disease under conditions of high stimulus-response compatibility.
反应时间范式提供了一组用于评估帕金森病中自主运动计划和执行方面的方法。注意力主要集中在反应编程问题上，采用简单反应时间（SRT）和选择反应时间（CRT）范式的组合。本研究的第一部分重复了早期的一项发现，即与SRT相比，患者在CRT中表现出不成比例的减慢。该研究的主要目的是调查反应选择的可能作用，反应选择是运动编程之前的一个关键阶段，在这种CRT缺陷中。操纵了两个因素：（i）反应不确定性和（ii）刺激 - 反应兼容性。在兼容条件下，随着不确定性的增加，患者的反应时间正常增加，并且在二选一任务中对刺激 - 反应兼容性有正常反应。然而，两组在两个实验因素之间表现出质的不同的相互作用模式，只有患者在四选一任务中对不兼容的刺激 - 反应关系表现出不成比例的减慢。根据哈斯布鲁克等人（1990年）的刺激 - 反应兼容性效应列表规则模型对数据进行了解释，该模型表明患者和对照组在处理不兼容的刺激 - 反应关系时使用了不同的策略。使用不同的策略使得无法确定帕金森病患者的处理是否受损，尽管建议进一步研究以澄清这个问题。然而，目前的数据表明，在高刺激 - 反应兼容性条件下，反应选择的任何损害都不太可能导致帕金森病中CRT的减慢。
