Guild Emma B, Vasquez Brandon P, Maione Andrea M, Mah Linda, Ween Jon, Anderson Nicole D
a Rotman Research Institute, Baycrest , Toronto , ON , Canada.
J Clin Exp Neuropsychol. 2014;36(7):751-60. doi: 10.1080/13803395.2014.941790. Epub 2014 Aug 30.
Previous studies have observed poorer working memory performance in individuals with amnestic mild cognitive impairment than in healthy older adults. It is unclear, however, whether these difficulties are true only of the multiple-domain clinical subtype in whom poorer executive functioning is common. The current study examined working memory, as measured by the self-ordered pointing task (SOPT) and an n-back task, in healthy older adults and adults with single-domain amnestic mild cognitive impairment (aMCI). Individuals with single-domain aMCI committed more errors and required longer to develop an organizational strategy on the SOPT. The single-domain aMCI group did not differ from healthy older adults on the 1-back or 2-back, but had poorer discrimination on the 3-back task. This is, to our knowledge, the first characterization of dynamic working memory performance in a single-domain aMCI group. These results lend support for the idea that clinical amnestic MCI subtypes may reflect different stages on a continuum of progression to dementia and question whether standardized measures of working memory (span tasks) are sensitive enough to capture subtle changes in performance.
以往研究发现，与健康的老年人相比，遗忘型轻度认知障碍患者的工作记忆表现较差。然而，目前尚不清楚这些困难是否仅存在于执行功能普遍较差的多领域临床亚型中。本研究通过自我排序指向任务（SOPT）和n-back任务，对健康老年人和单领域遗忘型轻度认知障碍（aMCI）成年人的工作记忆进行了检测。单领域aMCI个体在SOPT上出现更多错误，且需要更长时间来制定组织策略。单领域aMCI组在1-back或2-back任务上与健康老年人没有差异，但在3-back任务上的辨别能力较差。据我们所知，这是首次对单领域aMCI组的动态工作记忆表现进行描述。这些结果支持了临床遗忘型MCI亚型可能反映了向痴呆症进展连续体上不同阶段的观点，并对工作记忆的标准化测量（广度任务）是否足够敏感以捕捉表现中的细微变化提出了质疑。
