The Perirhinal Cortex and Implicit Memory

嗅周皮层和内隐记忆

• 批准号: 8251971
• 负责人: Wei-Chun Wang
• 金额: $ 3.5万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8251971
• 关键词: Affect; Alzheimer' s Disease; Awareness; Brain; Complex; Diagnosis; Discrimination; Disease; Epilepsy; Event; Exhibits; Familiarity; Free Association; Functional Magnetic Resonance Imaging; Hippocampus (Brain); Human; Impairment; Intention; Intervention; Left; Life; Lobectomy; Magnetic Resonance Imaging; Manuals; Measures; Medial; Memory; Memory Disorders; Memory impairment; Mental Depression; Mental disorders; Modeling; Morphologic artifacts; Movement; Participant; Patients; Phase; Play; Process; Production; Quality of life; Recruitment Activity; Resolution; Retrieval; Role; Scanning; Schizophrenia; Speech; Stroke; Symptoms; Temporal Lobe; Testing; Work; base; design; experience; implicit memory; insight; interest; long term memory; memory encoding; memory retrieval; nervous system disorder; novel; patient population; research study; theories; young adult

Many theories of human long term memory assume that explicit memory for prior events relies on the medial temporal lobes (MTLs) and its subregions. In contrast, implicit memory, measured in tasks where experience with a prior item facilitates the subsequent identification or production of that item, is thought to rely on cortical regions outside of the MTL. However, it has recently been hypothesized that the perirhinal cortex, a region within the MTL, holds high level conceptual and perceptual representations irrespective of awareness or intention. In one recent study, we provided evidence that the perirhinal cortex is sensitive to certain forms of implicit memory. We demonstrated that amnesic stroke and temporal lobectomy patients exhibited impaired conceptual implicit memory, and in a separate experiment showed that perirhinal activations at encoding predicted subsequent conceptual implicit memory. The experiments proposed here seek to extend these previous findings. In the first experiment, a novel paradigm that measures both conceptual implicit memory and explicit familiarity-based recognition will be used to assess the role of the perirhinal cortex in these two tasks. Participants will be scanned during recognition and free association memory tasks that measure familiarity and conceptual implicit memory, respectively. In the second experiment we will test the hypothesis that sufficiently complex perceptual discriminations will recruit the perirhinal cortex during both the encoding and retrieval phases of a perceptual implicit memory task. Both experiments will utilize high-resolution fMRI and region of interest alignment derived from manual MRI brain tracing. Moreover, for the first experiment we will develop a unique fMRI sequence designed to counteract movement artifacts intrinsic to overt speech. Understanding the conditions under which the perirhinal cortex processes and represents conceptual and perceptual information is critical to understanding the role of the MTLs in long term memory and beyond. The insights from these studies can be applied to diagnose, understand, and treat memory deficits and mental disorders that adversely affect memory.

许多关于人类长时记忆的理论认为，对先前事件的外显记忆依赖于内侧颞叶及其亚区域。相比之下，内隐记忆被认为依赖于MTL之外的皮层区域，而内隐记忆是在任务中测量的，在任务中，对先前项目的经验有助于随后识别或产生该项目。然而，它最近被假设，嗅周皮层，MTL内的一个区域，持有高层次的概念和知觉的代表性，无论意识或意图。在最近的一项研究中，我们提供的证据表明，嗅周皮层对某些形式的内隐记忆很敏感。我们证明了失忆性中风和颞叶切除术患者表现出受损的概念内隐记忆，并在一个单独的实验中表明，在编码的嗅周激活预测随后的概念内隐记忆。 这里提出的实验试图扩展这些以前的发现。在第一个实验中，一个新的范式，测量概念的内隐记忆和显式的熟悉为基础的识别将被用来评估在这两个任务的嗅周皮层的作用。参与者将在识别和自由联想记忆任务中进行扫描，分别测量熟悉度和概念内隐记忆。在第二个实验中，我们将测试的假设，即足够复杂的知觉歧视将招募在编码和检索阶段的知觉内隐记忆任务的嗅周皮层。这两个实验都将利用高分辨率功能磁共振成像和手动磁共振成像脑追踪的感兴趣区域对齐。此外，对于第一个实验，我们将开发一个独特的功能磁共振成像序列，旨在抵消运动伪影固有的公开讲话。 了解嗅周皮层处理和代表概念和感知信息的条件对于理解MTL在长期记忆和其他方面的作用至关重要。这些研究的见解可以应用于诊断，理解和治疗对记忆产生不利影响的记忆缺陷和精神障碍。