AGING & VISUAL-SPECIFICITY OF EXPLICIT & IMPLICIT MEMORY

正常衰老的一个关键特征是，记忆中的感性和概念性细节变得不那么丰富。这一特性主要反映了老年人以一种比年轻人更不具体、更一般的方式检索事件的倾向，并且在较小程度上编码在感知和概念上的差异更小。拟议的研究调查了支持感知细节记忆的神经系统随年龄的变化。为此，使用2种互补技术评估支持特定感知属性（视图大小）的对象和面孔的外显和内隐记忆的大脑区域的视觉特异性。1. 神经心理学研究将帕金森病作为额基底神经节功能障碍的模型，将轻度阿尔茨海默氏痴呆症作为MTL和后颅外功能障碍的模型，以评估这些脑系统对正常衰老相关疾病变化的贡献。2. 结合事件相关功能磁共振成像（fMRI）和同时记录的脑磁图（MEG）和事件相关电位（ERP），确定了可能损害感知记忆的年轻和老年大脑功能动态的差异。实验使用内隐记忆测试，外显记忆使用识别（而不是回忆）测试来评估，以揭示内隐和外显感知表征被编码的程度，并可能用于通过额叶策略搜索过程检索，这些过程随着年龄的增长而受损。研究结果还将有助于这些大脑系统的功能表征，并通过定义与年龄相关的记忆障碍相关的大脑区域，该工作解决了指定治疗应该针对哪些区域的临床目标。

A key feature of normal aging is that memory becomes less rich in perceptual and conceptual details. This property has been proposed to primarily reflect a tendency of elderly to retrieve events in a less specific and so more generic manner than young people and to a lesser extent encoding that is less perceptually and conceptually distinct. Proposed research investigates changes with age in neural systems supporting memory for perceptual details. To do so, the visual-specificity of brain areas supporting explicit and implicit memory for particular perceptual properties (view size) of objects and faces are assessed using 2 complementary techniques. 1. Neuropsychological studies use Parkinson's disease as a model for frontal-basal ganglionic dysfunction and mild Alzheimer's dementia as a model for MTL and posterior extrastriate dysfunction to assess the contributions of these brain systems to changes in normal aging age-related disorders. 2. Combined event-related functional magnetic resonance imaging (fMRI) and simultaneous magnetoencephalogram (MEG) and event-related potential (ERP) recordings in the same young and old normal people define differences in the functional dynamics of young and aged brains that may impair perceptual memory. Experiments use implicit memory tests, and explicit memory is assessed using recognition (not recall) tests to reveal the extent to which implicit and explicit perceptual representations are encoded and potentially available for retrieval using frontal lobe strategic search processes that are impaired with age. Findings will also contribute to the functional characterization of these brain systems, and by defining brain areas underlying age-related memory disturbances, the work addresses a clinical goal of specifying which regions should be targeted by treatments.