MR INFORMATION PROCESSING

先生信息处理

• 批准号: 3737745
• 负责人: TERRY L JERNIGAN
• 金额: --
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3737745
• 关键词: AIDS; AIDS dementia complex; HIV infections; caudate nucleus; cognition; cognition disorders; entorhinal cortex; hippocampus; human subject; image processing; magnetic resonance imaging; memory; neural information processing; neuroanatomy; neuropsychological tests; psychomotor function; psychoneuroimmunology; semantics

The major aim of the proposed work is to define the first specific functional and anatomical changes that occur in the brain in association with HIV infection, in cases uncomplicated by the presence of CNS opportunistic infections. Based on findings from a previous anatomical study of memory-impaired subjects, we have proposed a novel interpretation of the results of perceptual priming studies in such subjects. In brief, we obtained evidence that patterns of performance previously interpreted in terms of the subjects' limbic and neocortical damage neglected the important influence of concomitant striatal damage. Since there is evidence that HIV+ subjects frequently have damage in striatal structures, and may have additional damage in limbic and neocortical structures, the findings of our previous study are considered to have important implications for HIV+ subjects. We predict that, in the early stages, HIV- related encephalopathy will be associated with a specific pattern of behavioral deficits reflecting striatal and temporal limbic effects. Damage to the caudate nucleus in immunosuppressed HIV+ subjects is expected to produce impairment on perceptual-motor tasks, and to result in slowed perceptual identification and lexical access. In isolation, caudate damage and the subsequent perceptual-motor and lexical deficits are expected to be associated with hyperpriming on perceptual and lexical priming tasks, but normal discrimination of recently presented from novel material in recognition memory tasks. Temporal lobe limbic damage, on the other hand, is expected to result in reduced priming and reduced recognition memory. However, when both caudate and temporal limbic damage are present, the subjects are expected to exhibit poor perceptual-motor and lexical processing and poor recognition memory, but normal priming. In this instance it will be possible to show that apparently normal priming is due to augmentation of priming effects due to impaired lexical and perceptual processing of the material, combined with decrements in priming due to temporal limbic damage. Two parallel studies will be conducted to test specific hypotheses arising from this model: a neuroanatomical study in which volume losses in specific structures (as measured within the Imaging Core) will be correlated with task performance; and a functional MRI study, in which alterations in the level of activation within these structures will be correlated with behavioral and anatomical indices of encephalopathy. Seventy-five HIV+ subjects and 45 age- and education- matched controls will be examined. A series of computer-mediated, experimental tasks involving psychomotor, perceptual, and lexical processing; lexical and perceptual priming.; and explicit recall and recognition memory will be conducted. In addition, functional MR activation studies will be conducted at the time of the subjects' scheduled MRI follow-ups. The anatomical and activation studies will target the caudate nucleus (CN) and the hippocampus and adjacent parahippocampal gyrus (H/PG)

拟议工作的主要目的是确定第一个具体的 大脑中发生的相关功能和解剖学变化 患有艾滋病毒感染，在没有中枢神经系统存在的情况下 机会性感染。 根据之前的解剖学研究结果 针对记忆障碍受试者的研究，我们提出了一种新颖的解释 此类受试者的知觉启动研究结果。 简而言之， 我们获得的证据表明，先前解释的绩效模式 受试者的边缘系统和新皮质损伤的术语忽略了 伴随纹状体损伤的重要影响。 既然有 有证据表明 HIV+ 受试者的纹状体结构经常受到损害， 并且可能对边缘系统和新皮质结构造成额外的损伤， 我们之前的研究结果被认为具有重要意义 对 HIV+ 受试者的影响。 我们预测，在早期阶段，艾滋病毒 相关脑病将与特定模式相关 反映纹状体和颞叶边缘效应的行为缺陷。 免疫抑制的 HIV+ 受试者的尾状核预计会受到损害 对知觉运动任务产生损害，并导致速度减慢 感知识别和词汇访问。 孤立地讲，尾状核损伤 随后的知觉运动和词汇缺陷预计将是 与感知和词汇启动任务的超级启动相关，但是 对最近从新材料中呈现的正常歧视 识别记忆任务。 另一方面，颞叶边缘损伤 预计会导致启动减少和识别记忆减少。 然而，当尾状核和颞叶边缘同时存在损伤时， 预计受试者的感知运动和词汇能力较差 处理和识别记忆较差，但启动正常。 在这个 例如，将有可能表明明显正常的启动是由于 由于词汇和知觉受损而增强启动效应 材料的加工，加上由于底漆的减少 颞叶边缘损伤。 将进行两项平行研究来测试 该模型产生的具体假设：一项神经解剖学研究 特定结构中的体积损失（在成像中测量） Core）将与任务绩效相关；和功能性核磁共振研究， 其中这些结构内的激活水平发生变化 将与行为和解剖指标相关 脑病。 75 名 HIV+ 受试者和 45 名年龄和教育程度 - 将检查匹配的对照。 一系列以计算机为媒介的、 涉及精神运动、知觉和词汇的实验任务 加工;词汇和知觉启动。；以及明确的回忆和 将进行识别记忆。 此外，功能性MR 激活研究将在受试者预定的时间进行 MRI 随访。 解剖学和激活研究将针对 尾状核 (CN) 和海马及邻近的海马旁回 (高/PG)