Suzuki Ayuko, Shinozaki Jun, Yazawa Shogo, Ueki Yoshino, Matsukawa Noriyuki, Shimohama Shun, Nagamine Takashi
Department of Neurology and Neuroscience, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, Chuo-ku, Sapporo, Japan.
J Alzheimers Dis. 2018;61(4):1653-1665. doi: 10.3233/JAD-170801.
The mental rotation task is well-known for the assessment of visuospatial function; however, it has not been used for screening of dementia patients.
The aim of this study was to create a simple screening test for patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) by focusing on non-amnestic symptoms.
Age-matched healthy controls (age 75.3±6.8), patients with MCI (76.5±5.5), and AD (78.2±5.0) participated in this study. They carried out mental rotation tasks targeting geometric graphics or alphabetical characters with three rotating angles (0°, 90°, and 180°) and indicated the correct answer. Response accuracy and reaction time were recorded along with their eye movements using an eye tracker. To quantify their visual processing strategy, the run count ratio (RC ratio) was calculated by dividing the mean number of fixations in incorrect answers by that in correct answers.
AD patients showed lower accuracy and longer reaction time than controls. They also showed a significantly greater number of fixation and smaller saccade amplitude than controls, while fixation duration did not differ significantly. The RC ratio was higher for AD, followed by MCI and control groups. By setting the cut-off value to 0.47 in the 180° rotating angle task, we could differentiate MCI patients from controls with a probability of 80.0%.
We established a new screening system for dementia patients by evaluating visuospatial function. The RC ratio during a mental rotation task is useful for discriminating MCI patients from controls.
心理旋转任务以评估视觉空间功能而闻名；然而，它尚未用于痴呆患者的筛查。
本研究的目的是通过关注非遗忘症状，为轻度认知障碍（MCI）和阿尔茨海默病（AD）患者创建一种简单的筛查测试。
年龄匹配的健康对照组（年龄75.3±6.8）、MCI患者（76.5±5.5）和AD患者（78.2±5.0）参与了本研究。他们对具有三个旋转角度（0°、90°和180°）的几何图形或字母字符执行心理旋转任务，并指出正确答案。使用眼动仪记录反应准确性、反应时间以及他们的眼动。为了量化他们的视觉处理策略，通过将错误答案中的平均注视次数除以正确答案中的平均注视次数来计算运行计数比率（RC比率）。
AD患者的准确性低于对照组，反应时间更长。他们的注视次数也明显多于对照组，扫视幅度更小，而注视持续时间没有显著差异。AD组的RC比率更高，其次是MCI组和对照组。在180°旋转角度任务中将临界值设定为0.47时，我们可以以80.0%的概率区分MCI患者和对照组。
我们通过评估视觉空间功能建立了一种新的痴呆患者筛查系统。心理旋转任务期间的RC比率有助于区分MCI患者和对照组。
