Department of Psychiatry, University of California San Francisco San Francisco, CA, USA.
Front Psychol. 2013 Apr 26;4:211. doi: 10.3389/fpsyg.2013.00211. eCollection 2013.
A metaphor is a figure of speech in which a subject is symbolic of another unrelated object. In the present study, we examined neural patterns associated with both novel unfamiliar and conventional familiar metaphoric processing, and how these patterns are modulated by affective valence. Prior to fMRI scanning, participants received a list of word pairs (novel unfamiliar metaphors as well as conventional familiar metaphors) and were asked to denote the valence (positive, negative, or neutral) of each word pair. During scanning, participants had to decide whether the word pairs formed meaningful or meaningless expressions. Results indicate that participants were faster and more accurate at deciding that positively valenced metaphors were meaningful compared to neutral metaphors. These behavioral findings were accompanied by increased activation in the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and the right inferior parietal lobe (RIPL). Specifically, positively valenced novel unfamiliar metaphors elicited activation in these brain regions in addition to the left superior temporal gyrus when compared to neutral novel metaphors. We also found that the mPFC and PCC mediated the processing of positively valenced metaphors when compared to negatively valenced metaphors. Positively valenced conventional metaphors, however, elicited different neural signatures when contrasted with either neutral or negatively valenced conventional metaphors. Together, our results indicate that positively valenced stimuli facilitate creative metaphoric processes (specifically novel metaphoric processes) by mediating attention and cognitive control processes required for the access, integration, and selection of semantic associations via modulation of the mPFC. The present study is important for the development of neural accounts of emotion-cognition interactions required for creativity, language, and successful social functioning in general.
隐喻是一种修辞手法，其中一个主题象征性地代表另一个不相关的对象。在本研究中，我们检查了与新颖的不熟悉和传统的熟悉隐喻处理相关的神经模式，以及这些模式如何受到情感效价的调节。在 fMRI 扫描之前，参与者收到了一系列词对（新颖的不熟悉的隐喻以及传统的熟悉的隐喻），并被要求表示每个词对的情感效价（积极、消极或中性）。在扫描过程中，参与者必须决定这些词对是否形成有意义或无意义的表达。结果表明，与中性隐喻相比，参与者在判断积极效价的隐喻是否有意义时更快、更准确。这些行为发现伴随着内侧前额叶皮层（mPFC）、后扣带回皮层（PCC）和右侧下顶叶（RIPL）的激活增加。具体来说，与中性新颖隐喻相比，积极效价的新颖不熟悉隐喻除了左颞上回外，还会引起这些脑区的激活。我们还发现，与消极效价的隐喻相比，mPFC 和 PCC 介导了积极效价的隐喻的加工。然而，与中性或消极效价的传统隐喻相比，积极效价的传统隐喻会引起不同的神经特征。总之，我们的结果表明，积极效价的刺激通过调节 mPFC，促进了创造性隐喻处理（特别是新颖的隐喻处理），这需要注意力和认知控制过程的参与，以获取、整合和选择语义联想。本研究对于发展创造力、语言和一般成功的社会功能所需的情感-认知相互作用的神经解释具有重要意义。
