Perirhinal Cortex and Associative Memory

描述(申请人提供)：对于大多数日常生活行为来说，成功形成任意联想的记忆的能力是必不可少的。大量研究表明，海马体在联想记忆中起着关键作用。最近的研究表明，周边皮质(PRC)也参与其中，但对其在联想记忆中的作用知之甚少。这项研究计划将使用功能磁共振成像(FMRI)和新的行为范式来测试关于PRC如何促进联想识别的三种理论： (1)单元化理论认为，如果成对的项目被编码为一个单位，则PRC可以支持基于熟悉度的新联想识别，但海马体是回忆被编码为单独单位的项目之间关系所必需的。提出了新颖的功能磁共振实验，以测试PRC是否特别有助于识别被编码为单个单元的项目对之间的关联。平行的行为研究将测试单元化是否会影响熟悉度指数。 (2)领域理论认为，PRC支持对来自同一加工领域的项目之间的联系进行基于熟悉度的识别，但要求海马体支持对来自不同加工领域的项目之间的联系的回忆。提出了新的功能磁共振成像研究，以测试PRC是否支持来自相同加工领域的项目之间的关联，但不支持来自不同领域的项目之间的关联。此外，行为研究将测试领域内的关联是否会影响熟悉程度的行为指数，而不是跨领域的关联。 (3)项目与语境的绑定理论认为，PRC代表项目信息，PHC代表语境信息，该信息受海马体的约束。FMRI实验是为了检验对物品信息的回忆是否与PRC活动有关，而对上下文信息的回忆是否会导致PHC活动。 通过对这三种理论的检验，本研究为综合考虑编码加工、刺激域加工和提取加工影响的MTL功能理论的发展奠定了基础。一些精神疾病(如精神分裂症)和神经疾病(如阿尔茨海默病和创伤性脑损伤)与记忆障碍和内侧颞叶功能障碍有关。这项拟议的研究可能会改进这些疾病的诊断和治疗方法。公共卫生相关性内侧颞叶区域助记功能的基础研究至关重要，因为几种精神疾病(如精神分裂症)和神经疾病(如阿尔茨海默病和创伤性脑损伤)与记忆障碍和MTL功能障碍有关。这种记忆障碍可能会对患者的生活质量产生毁灭性的影响。澄清记忆的基本神经机制的研究可以改进这些疾病的诊断和治疗。

DESCRIPTION (provided by applicant): The ability to successfully form memories for arbitrary associations is essential for most acts of daily living. Numerous studies have shown that the hippocampus plays a critical role in associative memory. Recent work indicates that the perirhinal cortex (PRc) is also involved, but its functional role in associative memory is poorly understood. This research program will use functional magnetic resonance imaging (FMRI) and novel behavioral paradigms to test three theories of how the PRc contributes to associative recognition: (1) Unitization theory asserts that the PRc can support familiarity-based recognition of novel associations if the paired items are encoded as a single unit, but that the hippocampus is required for recollection of relations between items that are encoded as separate units. Novel FMRI experiments are proposed to test whether the PRc specifically contributes to recognition of associations between pairs of items that were encoded as a single unit. Parallel behavioral studies will test whether unitization influences indices of familiarity. (2) Domain theory asserts that the PRc supports familiarity-based recognition for associations between items from the same processing domain, but that the hippocampus is required to support recollection for associations between items from different processing domains. Novel FMRI studies are proposed to test whether the PRc supports associations between items from the same processing domains, but not associations between items from different domains. In addition, behavioral studies will test whether within-domain, but not across-domain associations influence the behavioral indices of familiarity. (3) Binding of items and contexts (BIC) theory asserts that the PRc represents item information, the PHc represents context information, and that this information is bound by the hippocampus. FMRI experiments are proposed to test whether recall of item information will be associated with PRc activity, whereas the recall of contextual information will lead to PHc activity. By testing the three theories, this proposal can provide the foundation for the development of a comprehensive theory of MTL function that can incorporate the influences of encoding processing, stimulus domain, and retrieval processing. Several psychiatric (e.g., schizophrenia) and neurological (e.g., Alzheimer's disease and traumatic brain injury) disorders are associated with memory impairments and with medial temporal lobe dysfunction. The proposed research may lead to improved diagnostic and therapeutic approaches to these disorders. PUBLIC HEALTH RELEVANCE Basic research on the mnemonic functions of the medial temporal lobe region is critically important because several psychiatric (e.g., schizophrenia) and neurological (e.g., Alzheimer's disease and traumatic brain injury) disorders are associated with memory impairments and MTL dysfunction. Such memory disorders can have a devastating effect on patients' quality of life. Research clarifying the basic neural mechanisms of memory can lead to improved diagnosis and treatment of these disorders.