Cognition and the basal ganglia. Separating mental and motor components of performance in Parkinson's disease.
Cognition and the basal ganglia. Separating mental and motor components of performance in Parkinson's disease.
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认知和基底神经节。
DOI：
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
F. J. Friedrich
中科院分区：
文献类型：
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作者：
R. Rafal;M. Posner;J. Walker;F. J. Friedrich
皮质下痴呆症的核心概念是，反应潜伏期的增加是由于思维过程的减慢，这是区分该综合征的原因。“迟缓”一词被用来描述帕金森氏症患者的思维迟缓，这意味着(1)反应潜伏期的延长不是严格意义上的运动，而是由于信息处理的迟缓，以及(2)精神迟缓类似于在运动区观察到的运动迟缓，因此可归因于多巴胺能基底节机制的功能障碍。目前的研究试图通过在帕金森氏症中寻找思维减慢来验证这个迟缓的定义，帕金森病可以直接与运动迟缓有关。研究人员对6名帕金森病患者进行了三项实验，这些实验允许将特定认知操作的速度与运动反应的速度分开。作为他们自己的对照，他们在帕金森氏症处于关闭状态时以及当运动迟缓通过药物治疗缓解时都进行了测试。对另外4例新诊断的帕金森病患者进行了L多巴/卡比多巴成功治疗前后的研究。第一个实验测量了记忆扫描的速度，第二个实验检测了注意在视野中的定向，第三个实验测量了准备手动动作所需的时间。结果表明，当患者处于未经治疗的状态时，总体反应时间增加，但没有伴随着纯粹认知成分的减慢。帕金森氏症患者经常报告的思维减慢并不一定伴随着运动迟缓，因此可能与多巴胺能功能障碍无关。这些发现强调，在从皮质下障碍反应潜伏期的增加推断思维减慢时需要谨慎。
Central to the concept of subcortical dementia is the implication that the increased response latencies, which distinguish the syndrome, are due to a slowing of thought processes. The term 'bradyphrenia' has been applied to this presumed slowing of thought in Parkinson's disease and implies (1) that increased response latencies are not strictly motoric but are due to slowed information processing, and (2) that the mental slowing is analogous to the bradykinesia observed in the motor domain and, hence, attributable to dysfunction of dopaminergic basal ganglia mechanisms. The current study attempts to validate this definition of bradyphrenia by seeking a slowing of thought in Parkinson's disease which can be linked directly to bradykinesia. Six parkinsonian patients with end-of-dose akinesia were studied in three experiments which allowed separation of the speed of specific cognitive operations from the speed of motor responses. Serving as their own controls, they were tested both during the parkinsonian 'off' state, and when bradykinesia was alleviated by drug therapy. Four additional patients with newly diagnosed Parkinson's disease were studied before and following successful treatment with L-DOPA/carbidopa. The first experiment measured the rate of memory scanning, the second examined orientating of attention in the visual fields, and the third measured the time required to prepare a manual movement. The results show that overall reaction time increased when patients were in the untreated state, but without a concomitant slowing of purely cognitive components. The slowing of thought often reported in Parkinson's disease does not necessarily accompany bradykinesia and thus may not be related to dopaminergic dysfunction. These findings emphasize the need for caution in inferring a slowing of thought from increased response latencies in subcortical disorders.