Department of Psychiatry, University of California San Francisco and San Francisco Department of Veterans Affairs Medical Center, San Francisco, CA, USA.
Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.
Neuropsychologia. 2012 Oct;50(12):2705-2719. doi: 10.1016/j.neuropsychologia.2012.07.020. Epub 2012 Jul 31.
The neural mechanisms underlying the process of understanding novel and conventional metaphoric expressions remain unclear largely because the specific brain regions that support the formation of novel semantic relations are still unknown. A well established way to study distinct cognitive processes specifically associated with an event of interest is to repeatedly present the same stimulus. The aim of the current study is to examine the neural signatures associated with forming new metaphoric concepts by repeatedly presenting novel as well as conventional metaphors. In an fMRI study, 11 subjects read novel and conventional two-word metaphoric expressions and decided whether the expressions were meaningful. Prior to the study, participants were presented with half of the conventional metaphors and half of the novel metaphoric expressions. The present results revealed that whereas repeated exposure to conventional metaphors elicited repetition suppression within the left supramarginal gyrus, no brain areas showed repetition suppression effects during the repeated exposure of novel metaphors. However, repetition enhancement effects for novel metaphors were found in several brain areas including the bilateral inferior parietal gyri. These findings suggest that the left and right supramarginal gyri are both involved in the conceptualization and the storage of novel semantic relations. This study is important to develop theoretical accounts of the formation of conceptual knowledge for both familiar and novel information.
理解新颖和传统隐喻表达的神经机制在很大程度上仍不清楚，主要是因为支持新颖语义关系形成的特定大脑区域尚不清楚。研究特定认知过程的一种成熟方法是反复呈现相同的刺激。本研究旨在通过反复呈现新颖和传统的隐喻来检查与形成新隐喻概念相关的神经特征。在 fMRI 研究中，11 名受试者阅读新颖和传统的双字词隐喻表达，并判断这些表达是否有意义。在研究之前，参与者被呈现一半的传统隐喻和一半的新颖隐喻表达。目前的结果表明，尽管反复接触传统隐喻会在左侧缘上回引起重复抑制，但在反复接触新颖隐喻时，没有大脑区域显示出重复抑制效应。然而，在几个大脑区域（包括双侧顶下小叶）中发现了新颖隐喻的重复增强效应。这些发现表明，左、右缘上回都参与了新颖语义关系的概念化和存储。这项研究对于发展对熟悉和新颖信息的概念知识形成的理论解释很重要。
