Kim Nam-Gyoon, Lee Ho-Won
Department of Psychology, Keimyung University, Daegu 42601, Korea.
Department of Neurology, School of Medicine & Brain Science and Engineering Institute, Kyungpook National University, Daegu 41566, Korea.
Healthcare (Basel). 2021 Feb 3;9(2):157. doi: 10.3390/healthcare9020157.
With visuospatial dysfunction emerging as a potential marker that can detect Alzheimer's disease (AD) even in its earliest stages and with disturbance in stereopsis suspected to be the prime contributor to visuospatial deficits in AD, we assessed stereoscopic abilities of patients with AD and mild cognitive impairment (MCI). Whereas previous research assessing patients' stereoacuity has yielded mixed results, we assessed patients' capacity to process coarse disparities that can convey adequate depth information about objects in the environment. We produced two virtual cubes at two different distances from the observer by manipulating disparity type (absolute vs. relative), disparity direction (crossed vs. uncrossed) and disparity magnitude, then had participants judge the object that appeared closer to them. Two patient groups performed as well as, or even better than elderly controls, suggesting that AD patients' coarse disparity processing capacity is capable of supporting common tasks involving reaching, grasping, driving, and navigation. Results may help researchers narrow down the exact cause(s) of visuospatial deficits in AD and develop and validate measures to assess visuospatial dysfunction in clinical trials and disease diagnosis.
随着视觉空间功能障碍成为一种即使在阿尔茨海默病（AD）的最早阶段也能检测到该病的潜在标志物，并且由于怀疑立体视觉障碍是AD患者视觉空间缺陷的主要原因，我们评估了AD患者和轻度认知障碍（MCI）患者的立体视觉能力。尽管之前评估患者立体视敏度的研究结果不一，但我们评估了患者处理粗略视差的能力，这种视差能够传达有关环境中物体的足够深度信息。我们通过操纵视差类型（绝对视差与相对视差）、视差方向（交叉视差与非交叉视差）和视差大小，在距离观察者两个不同距离处生成了两个虚拟立方体，然后让参与者判断哪个物体看起来离他们更近。两个患者组的表现与老年对照组一样好，甚至更好，这表明AD患者处理粗略视差的能力能够支持涉及伸手、抓握、驾驶和导航的常见任务。研究结果可能有助于研究人员缩小AD患者视觉空间缺陷的确切原因，并在临床试验和疾病诊断中开发和验证评估视觉空间功能障碍的方法。
