The Effect of Anticipation on Episodic Memory: Motivation and Attention

描述(申请人提供)：预期目标导向的过程，如注意力和动机，对学习和记忆有重大影响，但关于这些过程如何在人脑中发挥影响，仍有许多未知之处。情景记忆--对特定事件的记忆--关键依赖于内侧颞叶(MTL)结构的完整性，包括海马区(CA区、齿状回和下丘脑)和海马旁回(内嗅区、大脑周围区和海马区旁皮质)。MTL从涉及注意力和基于奖励的动机的大脑区域接受直接投射，包括后顶叶皮质(PPC)、前额叶皮质(PFC)和中脑。在刺激呈现之前，这些动机和注意网络的激活可能通过促进MTL内的刺激处理来影响记忆的形成。这项研究将使用功能磁共振成像(FMRI)来研究刺激呈现前启动的目标定向过程如何招募注意力和动机脑网络，并影响MTL中的记忆形成。实验一将使用高分辨率功能磁共振成像来检验基于奖励的动机通过与中脑结构的相互作用而不同地影响MTL次区域功能的假说。我们将研究在刺激呈现之前诱发多巴胺能中脑激活的动机激励是否增强MTL亚区内的记忆编码。实验2将检验注意线索可以偏向MTL加工和促进记忆形成的假设。我们将研究表明任务相关目标的预期线索是否在刺激呈现之前从PPC、PFC和任务相关MTL亚区引发激活，以及这是否导致增强的情景编码。实验三将考察完全注意和分散注意条件下基于奖赏的动机对联想记忆形成的影响，以检验动机通过注意资源分配驱动基于MTL的记忆形成的假设。通过增加对MTL内记忆功能的了解，这项工作有能力揭示已知的MTL结构和功能的变化，这些变化发生在正常衰老和精神疾病中，包括阿尔茨海默病、抑郁症、躁郁症和精神分裂症。这项拟议的研究考察了多巴胺能中脑和MTL之间的相互作用如何影响记忆，这将为了解涉及DA系统中断的疾病提供洞察力，包括帕金森氏症、抑郁症、双相情感障碍和精神分裂症。这项工作可能对理解精神分裂症患者的MTL功能障碍以及记忆和注意力障碍特别有帮助。

DESCRIPTION (provided by applicant): Anticipatory goal-directed processes, such as attention and motivation, have a significant impact on learning and memory, yet much is still unknown about how such processes exert their influence in the human brain. Episodic memory-memory for specific events-critically relies on the integrity of the structures of the medial temporal lobe (MTL), including the hippocampus (CA fields, dentate gyrus, and subiculum) and parahippocampal gyrus (entorhinal, perirhinal and parahippocampal cortices). The MTL receives direct projections from brain regions involved in attention and reward-based motivation, including posterior parietal cortex (PPC), prefrontal cortex (PFC), and midbrain. Activation of these motivational and attentional networks prior to stimulus presentation may influence memory formation by facilitating stimulus processing within the MTL. The research presented in this proposal will use functional magnetic resonance imaging (fMRI) to examine how goal-directed processes initiated prior to stimulus presentation recruit attentional and motivational brain networks and influence memory formation in the MTL. Experiment 1 will use high-resolution fMRI to test the hypothesis that reward-based motivation differentially affects MTL subregional function through interactions with midbrain structures. We will examine whether motivational incentives that elicit activation from dopaminergic midbrain prior to stimulus presentation enhance memory encoding within MTL subregions. Experiment 2 will test the hypothesis that attentional cues can bias MTL processing and facilitate memory formation. We will examine if anticipatory cues that indicate task-relevant goals elicit activation from PPC, PFC, and task-relevant MTL subregions prior to stimulus presentation, and whether this results in enhanced episodic encoding. Experiment 3 will examine the effects of reward-based motivation on associative memory formation under conditions of full and divided attention to test the hypothesis that motivation drives MTL-based memory formation through allocation of attentional resources. By increasing understanding of memory function within the MTL, this work has the ability to shed light on changes in MTL structure and function known to occur in normal aging and mental illnesses, including Alzheimer's disease, depression, bipolar disorder and schizophrenia. The proposed research examines how interactions between dopaminergic midbrain and MTL influence memory, which will provide insight into disorders that involve disruptions of the DA system, including Parkinson's disease, depression, bipolar disorder, and schizophrenia. This work may prove particularly informative for understanding the MTL dysfunction and impairments in memory and attention that occur in schizophrenia.