AGING & VISUAL-SPECIFICITY OF EXPLICIT & IMPLICIT MEMORY

正常衰老的一个关键特征是，记忆在知觉和概念细节上变得不那么丰富。这一特性被提出主要是为了反映老年人以比年轻人更不具体和更一般的方式提取事件的倾向，以及在较小程度上对感知和概念上较不明显的编码。拟议中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。为了做到这一点，使用两种互补的技术评估了支持物体和面部特定知觉属性(视图大小)的外显和内隐记忆的大脑区域的视觉专一性。1.神经心理学研究使用帕金森病作为额叶-基底节功能障碍的模型，将轻度阿尔茨海默病作为MTL和后纹状体外功能障碍的模型，以评估这些大脑系统在正常衰老相关疾病的变化中的贡献。2.结合事件相关功能磁共振成像(FMRI)和同步脑磁图(MEG)和事件相关电位(ERP)记录，在相同的青年和老年正常人中发现了可能损害知觉记忆的年轻和老年大脑功能动力学的差异。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，以揭示内隐和外显知觉表征被编码的程度，并可能用于使用随着年龄而受损的额叶策略性搜索过程进行提取。这些发现还将有助于这些大脑系统的功能表征，通过定义与年龄相关的记忆障碍的大脑区域，这项工作解决了指定哪些区域应成为治疗目标的临床目标。

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.