The Neuroscience of Metaphor Comprehension
The neuroscience of metaphor comprehension investigates brain activity associated with interpreting figurative language. It asks how processing varies with factors such as familiarity, novelty, context, task difficulty and language experience. There is no justification for treating metaphor as the product of one isolated brain location or a simple opposition between a literal left hemisphere and a metaphorical right hemisphere.
An experiment compares conditions using particular stimuli and measurements. Understanding what was compared is essential: a difference between unfamiliar metaphors and familiar literal phrases may reflect more than figurativeness alone.
What the methods measure
| Method or analysis | Information provided | Important limitation |
|---|---|---|
| EEG and event related potentials | Patterns of electrical activity, including changes timed to a word or other event | Scalp recordings do not directly identify a single thought or its precise source |
| Functional MRI | Changes in a blood oxygenation related signal associated with experimental conditions | The signal is indirect and depends on the task and comparison |
| Network analysis | Relationships among activity estimates under a defined analytical model | A statistical connection is not automatically an anatomical pathway or demonstrated causal mechanism |
The choice of method should match the question. Timing, localisation and relations among measured signals are different aspects of an explanation. Colourful images or technical vocabulary do not remove the need for a careful experimental contrast.
A network study of figurative expressions
Arzouan and colleagues recorded EEG while 28 native Hebrew speakers judged whether two word expressions were meaningful. Conditions included literal expressions, conventional metaphors, novel metaphors and unrelated words. The authors constructed and compared directed functional networks using their specified temporal analysis.[1]
The paper reports differences in network organisation across conditions and presents the approach as a way of examining coordinated activity. Its network representation is an analytical construction from the recordings. It should not be retold as a photograph of a metaphor travelling along a visibly identified wire in the brain.
Familiarity and difficulty
Schmidt and Seger's study explicitly separates figurativeness, familiarity and difficulty in an fMRI design, comparing literal sentences with different kinds of metaphorical sentence.[2] This identifies a central methodological problem: the label “metaphor” can cover expressions with very different demands.
For example, a familiar phrase encountered frequently in conversation differs from a novel poetic comparison requiring sustained interpretation. A useful study asks whether its conditions differ in word length, frequency, plausibility, context and response requirements, as well as in the theoretical property of interest.
Evidence from bilingual processing
Jankowiak, Rataj and Naskręcki compared Polish and English word pairs in a final sample of 23 late, proficient bilingual participants. Their event related potential results varied with language and expression type, including conventional and novel metaphors.[3]
An N400 difference is often discussed in relation to semantic processing, but it is not a unique “metaphor detector”. The study itself considers several possible processing interpretations. Its results should remain connected to the word pair task and participants' language histories rather than being generalised to every bilingual conversation.
From an observation to an explanation
Imagine a hypothetical experiment in which unfamiliar metaphors produce a larger response than familiar literal expressions. At least three questions follow. Was the difference due to figurativeness, unfamiliarity or their interaction? Did participants interpret the expressions successfully? Would providing a supportive context alter the pattern?
These are not reasons to dismiss the measurement. They identify what further comparisons would clarify its interpretation. Likewise, observing activity associated with movement during a language task would require additional evidence before concluding that movement simulation is necessary for all metaphor comprehension.
What neuroscience does not establish by itself
Brain activity during language comprehension does not demonstrate the effectiveness of an intervention, prove the historical origin of an expression or reveal a person's private symbolic meaning. Those claims require different evidence.
For this wiki, neural research can inform discussion of Embodied Cognition and figurative understanding. Any proposed connection to a particular practice should state the additional assumptions involved and distinguish them from what the cited experiment measured.
Related pages
- Learning Metaphor in a Second Language
- How Children Learn to Understand Metaphor
- Metaphor and Gesture
- Metaphor and Reasoning
References
- ↑ Yossi Arzouan, Sorin Solomon, Miriam Faust and Abraham Goldstein (2011), “Big Words, Halved Brains and Small Worlds: Complex Brain Networks of Figurative Language Comprehension”, PLOS ONE 6(4):e19345.
- ↑ Gwenda L. Schmidt and Carol A. Seger (2009), “Neural Correlates of Metaphor Processing: The Roles of Figurativeness, Familiarity and Difficulty”, Brain and Cognition 71(3), pp. 375–386.
- ↑ Katarzyna Jankowiak, Karolina Rataj and Ryszard Naskręcki (2017), “To electrify bilingualism: Electrophysiological insights into bilingual metaphor comprehension”, PLOS ONE 12(4):e0175578.