Episodic Memory Encoding: fMRI Investigations

描述（由申请人提供）：拟议研究的总体目标是从认知神经科学的角度了解有关事件的信息如何成功地编码到情景记忆中。将采用功能性磁共振成像（fMRI）来识别在成功编码实验项目（如单词和图片）及其与其他项目（项目-项目编码）或与一个或多个上下文特征（项目-上下文编码）的关联期间引发的神经活动。指导拟议的研究的理论观点来自的建议，情节记忆表示的处理从事的事件，因为它是经验丰富的，成功的情节编码需要构成一个事件的各种功能是“绑定”或整合到一个连贯的记忆表示。在这种观点的指导下，实验将解决大脑皮层和内侧颞叶在“绑定”内与跨模态项目上下文和项目项目关联的作用。其他实验将调查不同的上下文特征之间的内部和跨通道关联的形成的神经相关性。另一个实验将研究在不同时间呈现的项目之间形成时间关联的神经相关性。在研究的第二部分中，重点将放在似乎在情节编码中发挥“许可”作用的神经活动上，而不是支持特定学习任务所参与的过程。将进行实验以阐明i）通过在稍后的记忆测试中记住而不是忘记的研究项目在某些皮层区域中引起的神经活动的相对衰减的功能意义，以及ii）也预测稍后的记忆表现的刺激前活动的调制。情景记忆的残疾性损伤在几种常见的神经系统疾病中很突出，特别是阿尔茨海默病和创伤性脑损伤。情节记忆障碍也是几种常见精神疾病的重要组成部分，包括精神分裂症，抑郁症和创伤后应激障碍。此外，情节记忆随着年龄的增长而大幅下降，相对于其他类型的记忆，不成比例。拟议的研究将有助于详细了解支持正常功能的情景记忆的神经认知过程，这种理解对于阐明不同类型的情景记忆障碍和开发有效的治疗干预措施是必要的。公共卫生相关性：情景记忆（对独特事件的记忆）的残疾性损伤在许多神经和精神疾病中被发现。拟议的研究将有助于详细了解正常功能的情景记忆，这是必要的，如果不同类型的情景记忆障碍是充分理解和有效治疗。

DESCRIPTION (provided by applicant): The overarching goal of the proposed research is to understand, from a cognitive neuroscience perspective, how information about an event is successfully encoded into episodic memory. Functional magnetic resonance imaging (fMRI) will be employed to identify neural activity elicited during the successful encoding of experimental items such as words and pictures and their associations either with other items (item-item encoding), or with one or more contextual features (item-context encoding). The theoretical perspective guiding the proposed research derives from the proposals that an episodic memory is represented in terms of the processing engaged by an event as it is experienced, and that successful episodic encoding requires that the various features constituting an event are 'bound' or integrated into a cohesive memory representation. Guided by this perspective, experiments will address the roles of the cerebral cortex and the medial temporal lobe in the 'binding' of within- versus across- modality item-context and item-item associations. Other experiments will investigate the neural correlates of the formation of within- and across-modality associations between different contextual features. Another experiment will investigate the neural correlates of the formation of temporal associations between items presented at different times. In a second strand of the research, the focus will be on neural activity that appears to play a 'permissive' role in episodic encoding, rather than supporting processes engaged by a specific study task. Experiments will be conducted to elucidate i) the functional significance of the relative attenuation of neural activity elicited in some cortical regions by study items that are remembered rather than forgotten on a later memory test, and ii) modulations of pre-stimulus activity that also are predictive of later memory performance. Disabling impairments of episodic memory are prominent in several common neurological conditions, notably Alzheimer's disease and traumatic brain injury. Episodic memory dysfunction is also a significant component of several common psychiatric disorders, including schizophrenia, depression and post-traumatic stress disorder. In addition, episodic memory declines substantially and, relative to other kinds of memory, disproportionately, with increasing age. The proposed research will contribute to the detailed understanding of the neurocognitive processes that support normally-functioning episodic memory, an understanding that is necessary for the elucidation of different kinds of episodic memory disorders and the development of effective therapeutic interventions. PUBLIC HEALTH RELEVANCE: Disabling impairments of episodic memory - memory for unique events - are found in numerous neurological and psychiatric conditions. The proposed research will contribute to the detailed understanding of normally-functioning episodic memory that is necessary if different kinds of episodic memory disorders are to be fully understood and effectively treated.