Hélie Sébastien, Fansher Madison
Department of Psychological Sciences, Purdue University.
Neuropsychology. 2018 Sep;32(6):724-734. doi: 10.1037/neu0000459. Epub 2018 Jun 28.
Numerous studies documenting cognitive deficits in Parkinson's disease (PD) revealed impairment in a variety of tasks related to memory, learning, and attention. One ubiquitous task that has not received much attention, is categorization system-switching. Categorization system-switching is a form of task-switching requiring participants to switch between different categorization systems. In this article, we explore whether older adults and people with PD show deficits in categorization system-switching.
Twenty older adults diagnosed with PD, 20 neurologically intact older adults, and 67 young adults participated in this study. Participants were first trained in rule-based (RB) and later information-integration (II) categorization separately. After training on the tasks, participants performed a block of trial-by-trial switching where the RB and II trials were randomly intermixed. Finally, the last block of trials also intermixed RB and II trials were randomly but additionally changed the location of the response buttons.
Contrary to our hypothesis, the results show no difference in accuracy between older adults and people with PD during the intermixed trial block, as well as no difference in response time (RT) switch cost. However, both groups were less accurate during intermixed trial blocks and had a higher RT switch cost when compared with young adults. In addition, the proportion of participants able to switch systems was smaller in people with PD than in young adults.
The results suggest that older adults and people with PD have impaired categorization system-switching ability, and that this ability may be related to a decrease in tonic dopamine (DA) levels associated with normal aging and PD. (PsycINFO Database Record
大量记录帕金森病（PD）认知缺陷的研究表明，在与记忆、学习和注意力相关的各种任务中存在损害。一个尚未受到太多关注的普遍任务是分类系统切换。分类系统切换是一种任务切换形式，要求参与者在不同的分类系统之间进行切换。在本文中，我们探讨老年人和帕金森病患者在分类系统切换方面是否存在缺陷。
20名被诊断患有帕金森病的老年人、20名神经功能正常的老年人和67名年轻人参与了这项研究。参与者首先分别接受基于规则（RB）和信息整合（II）分类的训练。在任务训练后，参与者进行了一系列逐次试验切换的实验，其中RB和II试验随机混合。最后，最后一组试验同样随机混合了RB和II试验，但额外改变了反应按钮的位置。
与我们的假设相反，结果显示在混合试验组中，老年人和帕金森病患者在准确性上没有差异，反应时间（RT）切换成本也没有差异。然而，与年轻人相比，两组在混合试验组中的准确性都较低，RT切换成本较高。此外，帕金森病患者中能够切换系统的参与者比例低于年轻人。
结果表明，老年人和帕金森病患者的分类系统切换能力受损，并且这种能力可能与正常衰老和帕金森病相关的静息多巴胺（DA）水平下降有关。（PsycINFO数据库记录）
