The nature of item representations in memory.

我们研究的首要目标是了解记忆的本质和支持不同类别记忆表征的形成和提取的神经系统。这项研究的重点是项目记忆表征的性质。这项工作的目的是使用神经成像和眼动监测来揭示记忆中存在不同类型的项目表征，并了解支持项目有意识识别的潜在神经和行为机制。我们将考察在不同条件下不同区域的神经重复抑制效应、眼动重复效应和意识识别之间的关系，为多种类型的项目表征提供证据。我们预测，存在支持项目表征形成的互补神经系统(海马区和皮质区)。然而，这些陈述的性质以及它们支持有意识认识的方式将有所不同。我们认为，由大脑皮层(包括大脑周围皮质)调节的表征将是僵化和高度专门化的，因此，对先前观看的项目所做的任何改变(例如，视点、特征改变)都会导致知觉加工的改变和意识识别的下降。相比之下，海马体将通过整合相关信息来调节灵活的项目表征，即使在项目发生变化时，这些信息也可以用来支持有意识的识别。除了提供证据证明存在由不同神经系统调节的灵活和特定的项目表征外，这项工作还将把神经重复抑制效应与行为联系起来，并解决文献中关于构成眼动重复效应的神经系统的争论。最后，我们将揭示我们对单个项目的记忆是僵化和不变的，还是不断变化的，并受到随着时间推移而与之相关的信息的影响。后一项发现表明，“感知”和“记忆”并没有被清楚地划分，但这两个认知过程是相互影响的。

The overarching goal of our research is to understand the nature of memory and the neural systems that support the formation and retrieval of different classes of memory representations. The focus of this proposed research is on the nature of item memory representations. The objectives of this work are to use neuroimaging and eye movement monitoring to reveal the existence of distinct types of item representations in memory and to understand the underlying neural and behavioral mechanisms that support conscious recognition of items. We will examine the relationship between neural repetition suppression effects in distinct regions, eye movement repetition effects and conscious recognition under a variety of conditions to provide evidence for multiple types of item representations. We predict that there are complementary neural systems (hippocampus versus cortical regions) that support the formation of item representations. However, the nature of those representations, and the manner by which they support conscious recognition, would differ. We propose that representations mediated by the cortex, including the perirhinal cortex, would be inflexible and hyperspecific, such that any change made to a previously viewed item (e.g., viewpoint, feature change) would cause a change in perceptual processing and a decline in conscious recognition. By contrast, the hippocampus would mediate flexible item representations through the integration of associated information, which could be used to support conscious recognition even when the item has undergone a change. In addition to providing evidence that there are flexible, as well as specific, item representations mediated by distinct neural systems, this work will relate neural repetition suppression effects to behavior, and resolve debates in the literature regarding the neural systems that underlie eye movement repetition effects. Finally, we will reveal whether our memories for single items are inflexible and unchanging, or constantly in flux and influenced by the information that has come to be associated with them over time. The latter finding would suggest that 'perception' and 'memory' are not clearly delineated, but that these cognitive processes influence each other.