Effects of Visual Signal Strength on Alzheimer Cognition

描述（由申请人提供）：确定使阿尔茨海默病（AD）患者在日常生活中无法发挥最佳功能的因素是非常重要的。阿尔茨海默症患者视觉认知的大多数方面都受到损害，包括识别和区分物体、面孔和图案的能力。对患者和护理人员来说，无法识别所爱之人的面孔或不恰当地识别物体的危险是AD最具破坏性的特征。这些视觉缺陷是由大脑高阶关联区域的病理改变引起的，但也来自较低水平视觉处理区域的输入缺陷。阿尔茨海默氏症患者普遍存在基本视力障碍，这可以强有力地预测视觉认知缺陷。我们计划将我们对AD中视觉功能障碍的认知后果的了解应用于设计视觉系统操作，以改善这种疾病的认知缺陷。这些结果将表明哪些认知和记忆领域最容易受到视觉干预，并允许我们开发一种视觉公平的神经心理学测试电池，用于临床和研究。这项工作继续我们与波士顿和克利夫兰阿尔茨海默病中心的双重研究。这项新研究的主要特点是关注对比操作对记忆的影响，并将视觉处理的检查水平“向下”扩展到包括视网膜变化，“向上”扩展到包括在自然条件下评估的视觉能力与日常活动的关系。另一个扩展点是检查患有帕金森病（PD）的非痴呆个体。我们的具体目标是：(1)进行对比敏感度的实验操作，并记录记忆和认知的变化作为正常衰老，AD和PD的功能。(2)利用倍频技术和光学相干断层扫描检查视网膜和视神经功能，并将结果与视觉认知、记忆和日常活动联系起来。(3)评估运动检测，目标是确定哪些因素对性能最显著。(4)将视觉能力与日常功能联系起来，通过自然任务和成功参与视觉依赖的休闲活动和日常生活中的工具活动来评估。利用创新的技术，我们的发现将跨越视网膜、基本视觉、视觉认知、视觉记忆和日常功能的多个层面，我们将为改善正常老年人以及AD和PD患者的生活质量获得新的更全面的见解。

DESCRIPTION (provided by applicant): Identification of factors that keep individuals with Alzheimer's disease (AD) from functioning optimally in their daily lives is of singular importance. Most aspects of visual cognition are impaired in AD, including the abilities to recognize and discriminate objects, faces, and patterns. The inability to recognize the face of a loved one or the danger in inappropriately identifying an object are some of the most devastating features of AD for both the patient and the caregiver. These visual deficits arise from pathological changes in highorder association areas of the brain but also from defective input from lower-level visual processing areas. Impairments in basic vision are prevalent in AD and can strongly predict deficits in visual cognition. We plan to apply our knowledge of the cognitive consequences of visual dysfunction in AD to designing visual-system manipulations with the goal of ameliorating cognitive deficits in this disorder. These results will indicate which cognitive and memory domains are most accessible to visual interventions and allow us to develop a visually-fair neuropsychological test battery for clinical and research use. This work continues our dual-site study with the Alzheimer Disease Centers of Boston and Cleveland. Key features of the new study are its focus on the effect of contrast manipulation on memory, and the expansion of examined levels of visual processing "downward" to include retinal change and "upward" to include the relation of visual abilities to daily activities assessed under naturalistic conditions. Another point of expansion is in the examination of nondemented individuals with Parkinson's disease (PD). Our Specific Aims are: (1) To perform experimental manipulations of contrast sensitivity and to document changes in memory and cognition as a function of normal aging, AD and PD. (2) To examine retinal and optic nerve function with frequency-doubling technology and optical coherence tomography and relate findings to visual cognition, memory, and daily activities. (3) To assess motion detection with the goal of establishing which factors are most salient to performance. (4) To relate visual abilities to daily function, as assessed by naturalistic tasks and by successful engagement in vision-dependent leisure activities and instrumental activities of daily living. Using innovative techniques, our findings will span the multiple levels of retina, basic vision, visual cognition, visual memory, and daily function, and we will attain new and more comprehensive insights into improving the quality of life of normal elderly adults and those with AD and PD.