Zaiser Ann-Kathrin, Bader Regine, Meyer Patric
Experimental Neuropsychology Unit, Department of Psychology, Saarland University, Saarbrücken, Germany; Department of Applied Psychology, SRH University Heidelberg, Germany.
Experimental Neuropsychology Unit, Department of Psychology, Saarland University, Saarbrücken, Germany.
Cortex. 2022 Jan;146:74-88. doi: 10.1016/j.cortex.2021.07.017. Epub 2021 Oct 21.
Contrary to traditional theories of declarative memory, it has recently been shown that novel, arbitrary associations can rapidly and directly be integrated into cortical memory networks by means of a learning procedure called fast mapping (FM), possibly bypassing time-consuming hippocampal-neocortical consolidation processes. In the typical FM paradigm, a picture of a previously unknown item is presented next to a picture of a previously known item and participants answer a question referring to an unfamiliar label, thereby incidentally creating associations between the unknown item and the label. However, contradictory findings have been reported and factors moderating rapid cortical integration through FM yet need to be identified. Previous behavioral results showed that rapid semantic integration through FM was boosted if the unknown and the known item shared many features. In light of this, we propose that the perirhinal cortex might be especially qualified to support the rapid incorporation of these associations into cortical memory networks within the FM paradigm, due to its computational mechanisms during the processing of complex and particularly highly similar objects. We therefore expected that a high degree of feature overlap between the unknown and the known item would trigger strong engagement of the perirhinal cortex at encoding, which in turn might enhance rapid cortical integration of the novel picture-label associations. Within an fMRI experiment, we observed greater subsequent memory effects (i.e., stronger activation for subsequent hits than misses) during encoding in the perirhinal cortex and an associated anterior temporal network if the items shared many features than if they shared few features. This indicates that the perirhinal cortex indeed contributes to the acquisition of novel associations by means of FM if feature overlap is high.
与传统的陈述性记忆理论相反，最近有研究表明，通过一种称为快速映射（FM）的学习过程，新颖的、任意的关联可以迅速且直接地整合到皮质记忆网络中，这可能绕过了耗时的海马体-新皮质巩固过程。在典型的FM范式中，一个先前未知物品的图片会呈现在一个先前已知物品的图片旁边，参与者回答一个涉及不熟悉标签的问题，从而偶然地在未知物品和标签之间建立关联。然而，已有相互矛盾的研究结果报道，并且调节通过FM实现快速皮质整合的因素仍有待确定。先前的行为学结果表明，如果未知物品和已知物品具有许多共同特征，那么通过FM实现的快速语义整合会得到增强。鉴于此，我们提出，嗅周皮质可能特别适合支持在FM范式中将这些关联快速纳入皮质记忆网络，这是由于其在处理复杂且尤其高度相似的物体时的计算机制。因此，我们预期未知物品和已知物品之间高度的特征重叠会在编码时引发嗅周皮质的强烈参与，这反过来可能会增强新图片-标签关联的快速皮质整合。在一项功能磁共振成像（fMRI）实验中，我们观察到，如果物品具有许多共同特征，那么在编码过程中，嗅周皮质以及相关的前颞叶网络会出现更大的后续记忆效应（即，后续命中比未命中的激活更强）。这表明，如果特征重叠度高，嗅周皮质确实有助于通过FM获取新的关联。
