ASSOCIATIVE RETRIEVAL AND MISMATCH SIGNALS IN THE CA FIELDS OF HUMAN HIPPOCAMPUS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 虽然海马体在陈述性记忆中的作用已经得到了很好的证实，但组件子场所支持的机制仍然没有得到充分的说明。在包括齿状回、CA3、CA1和下丘的海马区内，已经假设CA3和CA1不同地支持基于记忆的关联预测和关联预测错误的检测。从这个角度来看，CA3被假定为编码联合记忆，这些记忆随后在关联提取过程中被“模式完成”，本质上是基于过去获得的关联知识对现在进行预测。CA3被认为将这些预测传递给CA1，CA1被定位为将来自记忆的输出与来自内嗅皮层的输入进行比较，内嗅皮层传输当前的“感觉现实”状态。 具体目的：我们试图研究人类CA3和CA1在关联检索和关联预测误差检测中的功能贡献。 方法和材料：采用高分辨率功能磁共振成像技术，检测大鼠大脑皮质、大脑皮质、海马旁、内侧和海马亚区的功能反应。受试者对面孔-房屋对进行编码，随后在3T进行扫描，同时执行线索回忆，然后进行匹配/不匹配探测决定。在每一次回忆试验中，一对被研究对象中的一个元素作为提取线索，随后是7.5%的S延迟，在此期间受试者试图提取关联对象。在延迟之后，出现了一个探测器？要么是正确的伙伴(匹配)，要么是错误的项目(不匹配)；受试者有750毫秒的时间做出反应。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. While the role of the hippocampus in declarative memory is well established, the mechanisms subserved by component subfields remain underspecified. Within the hippocampuswhich includes dentate gyrus, CA3, CA1, and subiculumit has been hypothesized that CA3 and CA1 differentially support memory-based associative predictions and the detection of associative prediction error. From this perspective, CA3 is posited to encode conjunctive memories that are subsequently "pattern completed" during associative retrieval, in essence making predictions about the present based on associative knowledge acquired in the past. CA3 is thought to pass these predictions to CA1, which is positioned to compare this output from memory with input from entorhinal cortex that transmits the present state of "sensory reality". Specific Aims: We seek to examine the functional contributions of human CA3 and CA1 to associative retrieval and the detection of associative prediction error. Methods and Materials: We used high-resolution fMRI to measure the functional response of MTL corticesperirhinal, parahippocampal, and entorhinaland the subfields of hippocampus. Subjects encoded face-house pairs, and were subsequently scanned at 3T while performing cued-recall followed by a match/mismatch probe decision. On each recall trial, one element of a studied pair served as the retrieval cue, which was followed by a 7.5-s delay during which the subject attempted to retrieve the associate. Following the delay, a probe was presented¿either the correct associate (match) or an incorrect item (mismatch); subjects had 750 ms to respond.