There are words whose power to evoke sensations has become proverbial. Just hearing them brings to mind the image, sound or feeling of that little fragment of reality they refer to. But what is the mechanism that accounts for this connection between a word and the mental imagery it conjures up?
A joint research project carried out by scientists from the Universitat Jaume I and the Cognition and Brain Sciences unit at the Medical Research Council in the UK has gone a step further towards finding an explanation for this phenomenon. With the help of magnetic resonance imaging, the team observed that reading words with strong connotations to odours not only triggers activity in the brain areas related to language, but also those linked to the sense of smell.
Garlic, stink, incense, urine, lemon, armpit, lavender… 23 people read these and another 53 words related to smells (either pleasant or unpleasant) that were jumbled up with another 60 words with no aromatic association. At the same time, images of their brain activity were registered using magnetic resonance. Findings showed that reading the words associated with a smell triggered activation of the area in the brain that processes olfactory information. More specifically, the areas involved were the primary olfactory cortex and the orbitofrontal cortex. In contrast, when the volunteers read words with no aromatic connotations, these regions of the brain remained inactive.
From these results, the researchers believe that when we acquire knowledge or experience about something that has a word to describe it, the brain connects the two pieces of information, that is, linguistic and sensory, in order to create the semantic meaning. “Given the fact that words are normally used with the objects and actions they refer to, the cortical neurons that process the information related with the words and with the objects are activated at the same time. In this way data about the referent and about the word are brought together through the cortical networks or neuronal webs”, the researchers explain in a paper that is soon to be published in the journal Neuroimage.