PRIMING DEFICITS & BRAIN SYSTEMS IN DEMENTIA & AMNESIA

描述(改编自调查人员摘要)：引爆是一种 内隐记忆，指的是仅仅对一个项目进行加工的事实 可以方便对相同物品的后续处理。引爆效果可以 在没有有意识地回忆之前的研究插曲的情况下发生， 有研究表明，启动和外显记忆是通过 不同的记忆系统。来自记忆障碍患者的证据是 对这一假设至关重要，因为如果有可能将故障 外显记忆和启动对不同大脑区域的损害 会强化独立记忆系统假说。许多研究 在健忘症患者和一些研究人员中发现了正常的启动效应 有报道称阿尔茨海默病患者的启动功能受损。 然而，与评估启动效果相关的许多困难 记忆受损的受试者。启动措施可能不像 外显记忆测量，以及在启动上缺乏群体差异 测量可能只是反映了测量灵敏度较低。的程度 在给定任务中获得的启动与处理效率有关(即， 基准性能)，效率较低的处理会产生更大的 引爆。因此，如果患者有轻微的加工障碍，这可能会 掩饰启动障碍。拟议的项目包括一系列 旨在操纵基线性能和敏感度的实验 启动措施。成人年龄范围的正常对照受试者 将对三组患者进行调查；可能患有 阿尔茨海默病、亨廷顿病和健忘症患者 病人。这些患者组的严重程度不同，明显 内存缺陷以及不同组件进程的程度 对他们的基线表现有贡献的人会受到影响。除了……之外 行为学测量，特定脑体积丢失的测量 结构将从核磁共振成像中获得。这些大脑测量将与 行为指数，使用多元回归方法，以 确定每个大脑区域在基线处理中的具体作用 启动的速度、外显记忆和强度。关于以下方面的具体假设 行为脑测量与结构脑测量的关系 从调查人员之前的研究中得出的结论将得到检验。

DESCRIPTION (adapted from investigator's abstract): Priming is a form of implicit memory, and refers to the fact that the mere processing of an item can facilitate subsequent processing of that same item. Priming effects can occur in the absence of conscious recollection of the prior study episode, and it has been suggested that priming and explicit memory are mediated by different memory systems. Evidence from memory disordered patients is critical for this hypothesis, since if it is possible to link the breakdown of explicit memory and priming to damage to different brain regions this would strengthen the independent memory systems hypothesis. Many studies have found normal priming effects in amnesic patients and some investigators have reported impaired priming in patients with Alzheimer's disease. However, many difficulties are associated with evaluating priming effects in memory impaired subjects. The priming measures may be less sensitive than explicit memory measures, and the lack of group differences on priming measures may simply reflect low measurement sensitivity. The degree of priming obtained in a given task is related to processing efficiency (i.e., baseline performance) with less efficient processing resulting in greater priming. Therefore, if patients have even mild processing deficits this may mask priming impairments. The proposed project consists of a series of experiments designed to manipulate baseline performance and sensitivity of the priming measures. Normal control subjects across the adult age range and three groups of patients will be investigated; patients with probable Alzheimer's disease, patients with Huntington's disease and amnestic patients. These patient groups differ in the severity of their explicit memory deficits and in the extent to which different component processes contributing to their baseline performance are compromised. In addition to the behavioral measures, measures of volume loss in specific brain structures will be obtained from MRI. These brain measures will be related to the behavioral indices, using a multiple regression approach, to determine the specific role of each brain region in baseline processing speed, explicit memory, and strength of priming. Specific hypotheses about the relationship between the behavioral and structural brain measures derived from the investigators' previous studies will be tested.