Cooper J A, Sagar H J, Tidswell P, Jordan N
Department of Clinical Neurology, University of Sheffield, UK.
Brain. 1994 Jun;117 ( Pt 3):517-29. doi: 10.1093/brain/117.3.517.
Studies of cognition and motor control have independently suggested that patients with Parkinson's disease show deficits in both attentional control and the preprogramming of movement. However, few studies have examined directly the involvement of cognitive processes in the origin of their slowed response. We examined the performance of 100 Parkinson's disease patients on simple reaction time (SRT) and a series of go/no-go cross-modality choice reaction time (CRT) tasks, in which motor response was constant; correct positive responses required attention to a progressively increasing number of dimensions of visual and auditory stimuli. The results showed that Parkinson's disease patients became increasingly impaired in response speed as choice complexity increased. Slowed response speed in Parkinson's disease involved two factors: (i) a 'perceptuomotor' factor which was constant across conditions and independent of choice complexity. Depression affected this factor selectively and independently of confounding associations with impoverished motor control; (ii) a 'cognitive-analytical' factor, which played an increasingly important role as complexity of choice increased. The characteristics of the relationship between response latency and cognitive complexity indicate that the deficit was due to a constant proportional slowing in cognitive speed across all SRT and CRT conditions. A cognitive deficit affecting the monitoring of stimulus-response compatibility may contribute to delayed response in Parkinson's disease. This cognitive-analytical deficit is present in early, untreated cases and, in contrast to perceptuomotor processes, is weakly related to depression.
对认知和运动控制的研究分别表明，帕金森病患者在注意力控制和运动预编程方面均存在缺陷。然而，很少有研究直接考察认知过程在其反应迟缓根源中的作用。我们对100名帕金森病患者进行了简单反应时（SRT）以及一系列执行/不执行跨模态选择反应时（CRT）任务的测试，其中运动反应保持不变；正确的阳性反应需要关注视觉和听觉刺激中越来越多的维度。结果显示，随着选择复杂性的增加，帕金森病患者的反应速度越来越受损。帕金森病患者反应速度减慢涉及两个因素：（i）一个“感知运动”因素，在各种条件下保持不变且与选择复杂性无关。抑郁选择性地影响这一因素，且与运动控制受损的混杂关联无关；（ii）一个“认知分析”因素，随着选择复杂性的增加发挥着越来越重要的作用。反应潜伏期与认知复杂性之间关系的特征表明，这种缺陷是由于在所有SRT和CRT条件下认知速度持续成比例减慢所致。影响刺激 - 反应相容性监测的认知缺陷可能导致帕金森病患者反应延迟。这种认知分析缺陷在早期未经治疗的病例中就已存在，并且与感知运动过程不同，它与抑郁的关联较弱。
