Effects of Visual Signal Strength on Alzheimer Cognition

描述(由申请人提供)：确定阻碍阿尔茨海默病(AD)患者在日常生活中发挥最佳功能的因素具有特别重要的意义。阿尔茨海默病患者视觉认知的大部分方面都受到损害，包括识别和辨别物体、人脸和图案的能力。对于患者和照顾者来说，无法识别所爱的人的脸或不适当地识别物体的危险是AD最具破坏性的一些特征。这些视觉缺陷是由大脑高级关联区域的病理变化引起的，也是由于来自较低级别视觉处理区域的输入缺陷引起的。阿尔茨海默病患者普遍存在基本视觉障碍，并可强烈预测视觉认知障碍。我们计划将我们对阿尔茨海默病视觉功能障碍的认知后果的知识应用于设计视觉系统操作，目的是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，并使我们能够开发出一套视觉公平的神经心理测试组件，供临床和研究使用。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站点研究。这项新研究的主要特点是，它专注于对比操作对记忆的影响，并将被检查的视觉处理水平向下扩展到包括视网膜变化，将视觉能力与在自然条件下评估的日常活动的关系包括在内。另一个扩展点是对帕金森氏症(PD)非痴呆症患者的检查。我们的具体目标是：(1)进行对比敏感度的实验操作，并记录正常衰老、AD和PD对记忆和认知的影响。(2)应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，并将检查结果与视觉认知、记忆和日常活动相关联。(3)评估运动检测，以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，如通过自然主义任务和成功参与依赖视觉的休闲活动和日常生活的工具性活动来评估。利用创新技术，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水平，并将获得新的、更全面的见解，以提高正常老年人和AD和PD患者的生活质量。

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.