The neural and behavioral causes underlying differences between visual perception and memory

项目总结 直到最近，人们还认为我们的记忆是作为感知的重新激活而发生的--重新召唤同样的感觉 视觉信息和神经模式(称为感觉恢复假说；例如，Buckner& 惠勒，2001)。然而，在最近的研究中，我们观察到知觉和认知之间的惊人差异 记忆，每个过程涉及不同的脑体素和模式(Bainbridge等人，2021b)。我们 观察到，大脑中的记忆表征失去了丰富的高级视觉信息，而神经元 对记忆敏感的人先于对知觉敏感的人。在这里，我们假设记忆 变得更加语义化的知觉表征，导致前神经向 更多的语义区域(Popham等人，2021)；我们称之为语义转换假说。这 这一假说与最近提出的记忆和知觉是由两个独立的 相邻网络(单独网络假说，Steel等人，2021)。通过检验这三个假说 结合起来，我们将能够识别支持视觉记忆的特定神经机制 以及它与视觉感知的关系。至关重要的是，这个项目对于理解记忆至关重要 阿尔茨海默氏症等疾病，最近的研究表明，这种疾病的视觉和语义信息 在图像中可以预测其在患者中的最终记忆命运(Bainbridge等人，2019a；Grande等人，2021)。 对于这个问题，我们使用了我们实验室首创的创新方法，包括直接读出 参与者的感知和记忆通过在线人群量化的图画- 采购(Bainbridge等人，2019a；Bainbridge，2021)。在目标1中，我们使用图形来识别直接 视觉和语义信息对视觉记忆表征的影响。在目标2中，我们使用 代表性相似性分析(Bainbridge等人，2021b)与功能磁共振相结合 成像测试视觉和语义信息对大脑记忆模式的作用。重要的是，在 除了测试典型个体外，我们还研究了先天性心脏病的新特征现象 失语症(患病率为2%-5%)，描述没有视觉记忆但视觉感知完整的个体 和语义记忆(Zeman等人，2015；Keogh&Pearson，2018)。失语症是一种自然的“敲门声” 来观察感知和记忆之间的行为和神经差异，以及我们的 实验室是到目前为止美国唯一研究过这种情况的实验室(Bainbridge等人， 2021A)。有了这个独特的群体，在目标3中，我们将确定支撑其 分离视觉记忆和视觉，并测试语义和视觉内容在记忆中的作用。 总而言之，这项研究有望解决我们对我们所见如何变成我们所记得的事情的理解， 通过找出在大脑中观察到的知觉和记忆之间这些显著差异的原因。

PROJECT SUMMARY Until recently, it was thought that our memories occur as a reactivation of perception – reconjuring the same visual information and neural patterns (dubbed the sensory reinstatement hypothesis; e.g., Buckner & Wheeler, 2001). However, in recent work, we observed surprising differences between perception and memory, with separate brain voxels and patterns involved in each process (Bainbridge et al., 2021b). We observed that memory representations in the brain lose rich high-level visual information, and that the neurons sensitive to memory are anterior to those sensitive to perception. Here, we hypothesize that memories become more semanticized representations of perception, resulting in an anterior neural shift towards more semantic regions (Popham et al., 2021); we dub this the semantic transformation hypothesis. This hypothesis runs counter to a recent proposal that memory and perception are supported by two separate yet adjacent networks (the separate networks hypothesis, Steel et al., 2021). By testing these three hypotheses in conjunction, we will be able to identify the specific neural mechanisms that support visual memory and its relation to visual perception. Crucially, this project has critical importance for understanding memory disorders such as Alzheimer’s Disease, for which recent work has shown that visual and semantic information in an image can predict its eventual memory fate in a patient (Bainbridge et al., 2019a; Grande et al., 2021). Towards this question, we utilize innovative methods pioneered by our laboratory, including a direct read-out of a participant’s perception and memory through drawings that are quantified through online crowd- sourcing (Bainbridge et al., 2019a; Bainbridge, 2021). In Aim 1, we use drawings to identify the direct influences of visual and semantic information on visual memory representations. In Aim 2, we use representational similarity analyses (Bainbridge et al., 2021b) combined with functional magnetic resonance imaging to test the roles of visual and semantic information on memory patterns in the brain. Importantly, in addition to testing typical individuals, we also study the newly characterized phenomenon of congenital aphantasia (2-5% prevalence), which describes individuals with no visual memory yet intact visual perception and semantic memory (Zeman et al., 2015; Keogh & Pearson, 2018). Aphantasia serves as natural “knock- out” case to observe behavioral and neural differences between perception and memory, and our laboratory is the only laboratory in the U.S. to have studied the condition thus far (Bainbridge et al., 2021a). Armed with this unique population, in Aim 3, we will identify the neural substrates that underlie their dissociation of visual memory and vision, and test the role of semantic vs. visual content on memory. In sum, this study promises to resolve our understanding of how what we see becomes what we remember, by identifying the causes of these striking differences observed in the brain between perception and memory.