The Neuropsychology of Memory

记忆的神经心理学

• 批准号: 9072384
• 负责人: Larry R Squire
• 金额: --
• 依托单位: VA SAN DIEGO HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9072384
• 关键词: Address; Affect; Aging; Alzheimer' s Disease; Awareness; Bilateral; Brain; Brain Injuries; Characteristics; Conscious; Diagnosis; Disease; Environment; Event; Exhibits; Experimental Designs; Eye Movements; Foundations; Functional Magnetic Resonance Imaging; Health; Hippocampus (Brain); Human; Individual; Injury; Knowledge; Learning; Lesion; Link; Measures; Medial; Memory; Memory Disorders; Memory impairment; Mental disorders; Nature; Neurologic; Neurology; Neuropsychology; Participant; Patients; Population; Reporting; Research; Sampling; Sampling Studies; Scanning; Short-Term Memory; Signal Transduction; Structure; Support System; System; Temporal Lobe; Testing; Time; Unconscious State; Veterans; Work; base; clinically relevant; combat; experience; improved; interest; learning materials; novel; prevent; public health relevance; research study; response; sample fixation; therapy development

 DESCRIPTION (provided by applicant): Difficulties with memory are among the most common complaints in the veteran population. The proposed work involves three related studies of the organization and neurology of human memory systems. The declarative memory system supports the capacity to learn and remember facts and events and depends on the hippocampus. Historically, declarative memory has been thought to represent conscious memory, i.e., knowledge that is accessible to awareness. Indeed, accessibility to awareness has been thought to be a defining feature of declarative memory. However, the characteristics of declarative (and nondeclarative) memory remain active topics of research, and the link between declarative memory, hippocampal function, and conscious knowledge is uncertain. One recent proposal is that memory can be hippocampus-dependent but can at the same time be inaccessible to conscious awareness. These issues became especially prominent following the discovery that eye movements can reflect a form of memory. For example, individuals scan a scene differently depending on whether the scene is novel or familiar. They make fewer fixations, sample fewer regions, and also (from our Preliminary Studies) sample different regions when viewing a familiar (rather than a novel) scene. What kind of memory effects are these? Do these eye movement effects simply provide another measure of conscious, declarative memory? Alternatively, are they automatic and independent of awareness that a scene is novel or familiar? Furthermore, are they hippocampus-dependent or hippocampus-independent? The nature of eye movements has potential clinical relevance for veterans with limited response capability. These questions will be addressed in three experiments. The first experiment (1a) aims to determine whether experience-dependent eye movements vary with the strength of declarative memory (four levels of strength will be established by varying the number of scenes to be remembered and the retention interval across four groups of participants). Experiment 1b will test well-characterized memory-impaired patients with bilateral hippocampal lesions to ask whether these experience-dependent eye movements are hippocampus-dependent. The second experiment (2a) introduces a novel experimental design to ask, scene by scene, whether experience-dependent eye movements occur only when individuals consciously (explicitly) recognize a scene as familiar, or whether these eye movements are automatic and occur independently of the conscious experience of recognition. Experiment 2b will test memory-impaired patients to ask, under different conditions than Experiment 1b, whether experience dependent eye movements are hippocampus-dependent. The third experiment turns to functional magnetic resonance imaging (fMRI), using an improved eye movement tracker compatible with the fMRI environment. Hippocampal activity increases when familiar scenes are presented and is even greater when scenes are recognized with high confidence. Here the question is whether hippocampal activity, recorded in response to familiar scenes, correlates with the eye movement effects. Is there a tight relationship between these two measures, or do eye movements to familiar vs. novel scenes occur independently of hippocampal activity. Through these three experiments, it should be possible to decide what kind of memory is expressed through eye movements, whether it is conscious or unconscious memory, and whether it is hippocampus-dependent or independent. These questions are foundational to understanding the memory systems of the human brain.

 描述（由申请人提供）： 记忆困难是退伍军人人口中最常见的抱怨之一。提出的工作涉及有关人类记忆系统组织和神经病学的三项相关研究。声明性记忆系统支持学习和记住事实和事件的能力，并取决于海马。从历史上看，宣告性记忆被认为代表意识，即知识可被意识获得的知识。确实，意识的可及性是认为声明性记忆的定义特征。然而，声明性（和非分离性）记忆的特征仍然是研究的主题，声明性记忆，海马功能和有意识的知识之间的联系尚不确定。最近的一个建议是，记忆可以依赖海马，但同时却无法获得意识意识。在发现眼动物可以反映出一种记忆形式的发现之后，这些问题变得尤为突出。例如，个人根据场景是新颖的还是熟悉的情况进行扫描不同的场景。它们的固定量更少，采样较少的区域，并且（根据我们的初步研究）在观看熟悉（而不是新颖的）场景时采样不同的区域。这些是什么样的记忆影响？这些眼动效应是否只是提供了有意识的声明性记忆的另一种衡量标准？另外，它们是自动的，并且独立于意识到场景是新颖的还是熟悉的？此外，它们是海马依赖性还是海马独立的？眼睛运动的性质对于反应能力有限的退伍军人具有潜在的临床相关性。这些问题将是 在三个实验中解决。第一个实验（1A）旨在确定与经验相关的眼动运动是否随声明性记忆的强度而变化（通过改变要记住的场景数量以及四组参与者的保留间隔，可以确定四个级别的强度级别）。实验1B将测试具有双侧海马课程的特征良好的记忆力障碍患者，以询问这些依赖经验的眼动运动是否依赖于海马。第二个实验（2a）引入了一种新型的实验设计，以逐场询问，与经验相关的眼动运动是否仅在个人有意识地（明确地）认识到一个熟悉的场景时才发生，或者这些眼睛运动是自动的，并且是否独立于有意识的识别体验。实验2b将测试与实验1b不同条件下的记忆力障碍患者，询问经验依赖的眼球运动是否依赖于海马。第三个实验使用与fMRI环境兼容的改进的眼动追踪器，转向功能性磁共振成像（fMRI）。当出现熟悉的场景时，海马活动会增加，并且当场景以高信心认识到场景时甚至更大。这里的问题是，海马活动是根据熟悉的场景记录的，与眼动效应相关。这两种措施之间存在密切的关系，还是将眼睛运动与熟悉的与新场景之间的关系独立于海马活动。通过这三个实验，应该可以通过眼动，无论是有意识还是无意识的记忆，以及它是海马依赖性还是独立。这些问题是理解人脑的记忆系统的基础。