Effect of aging on item and context memory, neural function, and neural structure

描述(申请人提供)：健康老年人的记忆缺陷很可能是内侧颞叶(MTL)结构和前额叶皮质(PFC)衰退的结果。对不同类型信息的记忆(项目与背景信息)可能依赖于MTL和PFC内的不同区域，并可能受到年龄的不同影响，尽管神经生物学证据很少。此外，还不清楚PFC和MTL在灰质、白质还是两者的组合中的变化对年龄对记忆的有害影响更大。使用一种新颖的实验范式，年轻人和老年人将在白色背景上研究物体，并在丰富的视觉环境中研究物体。在接受功能磁共振成像(FMRI)的过程中，参与者将接受一项记忆测试，该测试将评估物体识别、附带检索上下文信息和有意检索上下文信息。为了评估大脑中白质的完整性，参与者还将接受扩散张量成像(DTI)。老年人将接受一系列全面的神经心理测试，旨在评估记忆和执行功能，其结果将被用来调查fMRI激活模式、脑白质完整性以及项目和上下文记忆方面的个体差异。因此，该项目将是首批调查健康老年人的项目与背景记忆(附带的和有意的)、白质完整性、功能激活模式和神经心理状态之间的关系的研究之一。阐明健康老年人的记忆和神经功能与年龄相关的变化对于开发有助于早期发现破坏性痴呆疾病(如阿尔茨海默病和脑血管疾病)的范例至关重要。早期发现疾病过程可能导致早期干预，以最大限度地减少患者的记忆力衰退，延长自主性，并减轻照顾者的负担。然而，首先有必要阐明健康老年人记忆的神经关联，以便人们可以发现正常衰老过程和前驱疾病过程之间的细微差异。这项拟议的项目旨在全面评估与年龄相关的记忆和神经结构和功能的变化，并为未来的临床研究提供经验基础，这些研究旨在通过功能磁共振成像和DTI来评估干预对记忆功能和神经完整性的疗效。

DESCRIPTION (provided by applicant): Memory deficits in healthy older adults are most likely a consequence of decline in medial temporal lobe (MTL) structures and prefrontal cortex (PFC). Memory for different types of information (item versus context information) may rely on various regions within MTL and PFC, and may be differentially impacted by aging, although neurobiological evidence is scare. Furthermore, it is unclear whether PFC and MTL changes in grey matter, white matter, or a combination, more strongly influence the deleterious effect of age on memory. Using a novel experimental paradigm, young and older adults will study objects on a white background and objects in a rich visual context. While undergoing functional Magnetic Resonance Imaging (fMRI), participants will receive a memory test that will assess object recognition, incidental retrieval of contextual information, and intentional retrieval of contextual information. To assess white matter integrity in the brain, participants will also undergo Diffusion Tensor Imaging (DTI). Older adults will receive a comprehensive battery of neuropsychological tests designed to assess memory and executive function, the results of which will be used to investigate individual differences in fMRI activation patterns, white matter integrity, and item and context memory. Thus, the project proposed will be one of the first studies to investigate the relationship between item and context memory (incidental and intentional), white matter integrity, functional activation patterns, and neuropsychological status in healthy older adults. Elucidation of age-related changes in memory and neural function in healthy older adults is critical to the development of paradigms that will facilitate early detection of devastating dementing illnesses such as Alzheimer's disease and Cerebrovascular Disease. Early detection of disease processes could lead to early intervention to minimize memory decline in patients, prolong autonomy, and reduce caregiver burden. However, it is first necessary to elucidate neural correlates of memory in healthy older adults so that one may detect subtle differences between normal aging and prodromal disease processes. The proposed project aims to provide a comprehensive assessment of age-related changes in memory and neural structure and function, and could provide an empirical foundation for future clinical studies aimed at assessing the efficacy of intervention in memory function and neural integrity as measured by fMRI and DTI.