Summary: A new study involving a person without somatosensation shows that direct sensory experience is not necessary to understand or use abstract metaphors and sensory language.
Source: University of Chicago
People who are blind or colorblind can still describe colors and use expressions such as “green with envy” or “feeling blue.” Someone with hearing loss might call a bright color “loud.” Despite these examples, many researchers have assumed that somatosensation—touch, pain, pressure, temperature, and proprioception (the sense of body position)—is essential for grasping metaphors rooted in tactile experience.
It has been widely believed that phrases like “she’s having a tough time” or “that exam was hard” require prior physical experience of those sensations in order to extend their meanings into abstract, metaphorical contexts.
New research from the University of Chicago, centered on a single, rare individual, challenges this assumption. The study finds that a person born without somatosensory perception can both understand and produce tactile language and metaphors, suggesting that direct sensory memory is not always required for such language use.
Life without somatosensation
Since 2014, Peggy Mason, PhD, Professor of Neurobiology, has worked with Kim (who agreed to be identified by her first name), a woman born without somatosensation. Kim lacks the peripheral sensory nerve fibers that convey touch, pain, pressure, temperature, and proprioceptive signals. As a result, she cannot stand or walk independently because maintaining balance without proprioceptive feedback is extremely difficult.
Because she cannot feel her body in the usual way, Kim relies heavily on other senses to interpret the world. To judge how hard an object is, she listens to the sound it makes when tapped. She uses visual information to infer textures and shapes. Yet she has never had direct tactile experiences to store as sensory memories and later draw upon when speaking or understanding metaphors.
Despite this absence of bodily sensation, Kim performed as well as control participants on a multiple‑choice test that required selecting the most appropriate sensory expression to complete short sentences. Her performance extended to both tactile-based and non-sensory idioms.
“Phrases like ‘driving a hard bargain’ originate from sensory words,” Mason said. “Because Kim has no somatosensation, we wondered how she would handle them. The results show that although sensory experience matters for many people, it is not strictly necessary—language can be learned and used without direct physical sensations.”
To explore how Kim acquires and uses tactile language, Mason collaborated with linguists Jacob Phillips, PhD, and Lenore Grenoble, PhD, from the University of Chicago Department of Linguistics. Grenoble noted that Kim offers a rare opportunity to test theories that previously could not be directly evaluated because nearly everyone has at least some somatosensory experience or memories of it.
“Kim is unique because she has never had these sensations at all,” Grenoble said. “That makes her an invaluable case study. Even if it’s a study of one person, it yields powerful evidence.”
Learning by association rather than direct experience
The research included Kim plus two control groups: thirty-nine native American English speakers recruited online and twenty-four of Kim’s friends and family, to control for any local or social variations in idiom usage. The test contained 80 items. Each item presented a brief scenario followed by four idiomatic choices. For example:
Liza bought her first car and successfully negotiated the price down five thousand dollars. Liza:
a) drove a hard bargain. (correct answer)
b) made a rough guess.
c) missed the mark.
d) hit the hay.
Kim identified the correct choices at rates comparable to or better than the control groups. She handled tactile metaphors and idiomatic expressions just as reliably as other participants. Grenoble says these findings contribute directly to the debate over embodied cognition and metaphor.
“This study provides data showing that somatosensory experience is not required,” she said. “That opens important questions about how such meanings are learned, how they change over time, and how they are employed in everyday communication.”
Beyond the test, conversational analysis offered insight into Kim’s understanding. During a discussion about the word “gritty,” Kim assumed the food grits must be gritty because the words share a root. Her mother corrected this, noting that cooked grits are not gritty, and Kim explained how she forms word meanings.
“I think pretty literally about words, especially about sensations,” Kim said. “Words like ‘gritty,’ ‘soft,’ ‘hard,’ or ‘coarse’—my definitions come strictly from what other people have told me. That’s where I get them.”
Grenoble observes that this exchange illustrates how Kim constructs meanings through linguistic input rather than firsthand sensation. “Most people likely learn these metaphors through association and language exposure,” she said. “They are not strictly literal meanings, so interpreting them is a linguistic process. Kim demonstrates that such interpretation does not require somatosensory memory.”
Mason, who has also studied how Kim and another person without somatosensation use visual cues to form a sense of their bodies in space, said she plans additional collaborations with Grenoble and Phillips to analyze how Kim describes objects, gestures, and bodily states.
“Kim has been an extraordinary participant and collaborator,” Mason said. “Working with her has led to rich, enjoyable research and has expanded our understanding of perception, language, and embodiment.”
Funding: The study was supported by the Neubauer Collegium for Culture and Society at the University of Chicago.
About this neuroscience research news
Author: Matt Wood
Source: University of Chicago
Contact: Matt Wood – University of Chicago
Image: The image is in the public domain
Original Research: Open access. “The unembodied metaphor: comprehension and production of tactile metaphors without somatosensation” by Peggy Mason et al., Frontiers in Communication
Abstract
The unembodied metaphor: comprehension and production of tactile metaphors without somatosensation
Introduction: Proposals for embodied metaphor and embodied cognition claim that abstract concepts are often understood through mental simulations of past sensory experiences. While exceptions exist for common sensory impairments such as vision or hearing loss, somatosensation (including proprioception, haptic touch, pain, pressure, and temperature) has been widely assumed to play a fundamental role in understanding sensory metaphors and many forms of abstract thought. If so, a person born without somatosensation would be expected to struggle with metaphors and concepts tied to bodily experience.
Methods: To test comprehension of sensory metaphors, researchers asked Kim to choose the most appropriate idiomatic expression for a variety of short contexts. Two control groups—friends and family of Kim and a representative sample of online participants—also completed the survey. In addition, six hours of Kim’s spontaneous speech were transcribed and analyzed for natural use of somatosensory metaphors.
Results: Kim’s responses on the idiom survey matched control performance despite her lack of somatosensory experience. Analysis of spontaneous speech showed she naturally and appropriately uses tactile expressions in both literal and metaphorical senses.
Discussion: Together, these findings indicate that linguistic and social experience can substitute for direct sensory experience when learning and using tactile language. The study demonstrates that people can comprehend and produce tactile metaphors without recruiting past somatosensory sensations, challenging a strong interpretation of embodied cognition that requires sensory simulations for language comprehension and abstract thought.