Poets have long known that metaphors can elevate words to higher level. Now scientists know part of the reason why: A new study suggests that reading metaphors, specifically those with words associated with taste, recruits areas of the brain associated with emotion.
It is the first neuroscience study to look at figurative language related to taste, says Francesca Citron of Freie Universität Berlin, author of the new work, just published in the Journal of Cognitive Neuroscience. She and co-author Adele Goldberg of Princeton University wanted to see if metaphorical concepts related to taste recruited brain regions engaged when we, say, eat a strawberry.
The study used 37 simple metaphorical sentences and their literal counterparts, which differed by only a single word – such as “The break-up was bitter for him” versus “The break-up was bad for him.” The researchers recorded participants’ brain activity as they silently read these sentences.
As a control, they also presented the participants with the critical words in isolation at the end of the experiment. This control was to make sure the gustatory brain regions were also active when participants read literal words about taste (for example, interpreting “sweet” as “sugary”).
They found that the taste metaphors engaged not only taste-related areas of the brain but also emotion-related areas more than did the literal sentences. Citron talked with CNS about these results and future work to better understand how we process different types of metaphors – including how multilingual people use metaphors.
CNS: How did you become interested in studying this topic?
Citron: Adele and I have done relevant work on embodied metaphors, when people use metaphors in order to describe something abstract in more concrete terms – such as saying he is sexy by saying he is hot. In this way, metaphors might facilitate conceptualization. We ran some behavioral experiments targeting different types of metaphors and then decided to tackle these issues from a neuroscientific perspective. In this way, we combined Adele’s background in cognitive linguistics with my background in neuroscience and emotion processing.
CNS: Why did you use taste metaphors specifically?
Citron: Very few studies had investigated related issues at the neural level and these studies had targeted other domains, such as motion – action idioms such as kick the bucket and grasp the idea – and texture metaphors – such as she had a rough day and that’s a slimy person. The taste domain had not been investigated yet.
CNS: Would you please highlight any novel elements to your experimental design? And how does this work fit in or diverge from past work on this topic?
Citron: First, we found that the comprehension of abstract, conventional metaphors related to taste does indeed recruit gustatory brain representations, which is a novel result as no previous study of embodied metaphors had targeted the taste domain. Beyond that, what we found most interesting was something we hadn’t anticipated: The metaphorical sentences activated brain regions associated with emotion processing more strongly than their literal counterparts – i.e., left amygdala and the anterior portion of the hippocampus and parahippocampal gyrus.
This suggests that metaphorical formulations were more emotionally engaging than literal expressions, despite the fact that the meanings involved were explicitly judged to be nearly identical. It is possible that metaphors are more emotionally engaging because they tend to activate physical experiences. We hope to explore this possibility in future work.
No experimental neuroscientific study of figurative language had yet addressed the question of whether metaphors are more emotionally engaging than literal expressions, despite some limited behavioral work, dated some decades back, on the topic.
The new results are in line with a meta-analysis of 23 studies on figurative language published by Bohrn and colleagues in 2012, which found more activation of the left amygdala in response to figurative expressions. Because meta-analyses cannot control for all psycholinguistic variables, we were excited to find the result with carefully matched stimuli. We are now doing follow up studies to determine whether the same effect holds across a range of metaphors.
CNS: Why do you think people like to use metaphorical phrases?
Citron: The results suggest that metaphorical phrases are more engaging than literal ones, which would help the speaker or writer attract and maintain the listener or reader’s attention, and they may facilitate processes such as affiliation, persuasion, and support. There is some evidence showing that we tend to use idiomatic expression when we seek affiliation in formulating complaints, for example.
CNS: What is the take-home message of the study?
Citron: At least in certain contexts, it may be useful to use figurative language in order to communicate more effectively. As a listener, one should be wary of being overly influenced by metaphorical language.
CNS: What’s next for this work?
Citron: As previously mentioned, we would like to generalize our work to different types of metaphors – not only taste-related ones – and we are in the process of implementing the next study. In the near future, we would like to investigate second language speakers’ comprehension and use of figurative expressions, as these often represent a challenge even for proficient speakers of a second language. In addition, we would like to test different ways of teaching figurative language to second-language speakers and assess the communicative and social consequences of mastering these expressions.
CNS: You speak 7 languages (Italian, English, German, Portuguese, Spanish, French, Modern Greek). Do you have any personal experiences in using/understanding metaphors in other languages that you could share?
Citron: I remember my Portuguese teacher putting a lot of emphasis on colloquial expressions such as sayings, idioms and proverbs, but also on the most typical ways of expressing things, for example you say native language, not mother tongue, an expression many foreigners would come up with. Using common and figurative expressions makes you sound more “similar,” less foreign, and facilitates your communication in the target second language.
CNS: How have your personal experiences with language impacted your research?
Citron: The suggestion of working on embodied metaphors came from Adele, but I think it found a very good match with my own interests and curiosity. I find that many figurative expressions are shared across cultures – for example, to kill two birds with a stone would involve rabbits in Portuguese, flies in German and pigeons in Italian – but, on the other hand, many of them are very culture-specific and sometimes very difficult to explain.
-Lisa M.P. Munoz
The paper, “Metaphorical Sentences Are More Emotionally Engaging than Their Literal Counterparts” by Francesca Citron and Adele Goldberg, was published in the Journal of Cognitive Neuroscience online on May 6, 2014.