Reading salt activates gustatory brain regions: fMRI evidence for semantic grounding in a novel sensory modality

Abstract

Because many words are typically used in the context of their referent objects and actions, distributed cortical circuits for these words may bind information about their form with perceptual and motor aspects of their meaning. Previous work has demonstrated such semantic grounding for sensorimotor, visual, auditory and olfactory knowledge linked to words, which is manifest in activation of the corresponding areas of the cortex. Here we explore the brain basis of gustatory semantic links of words whose meaning is primarily related to taste. In a blocked fMRI design, Spanish taste words and control words matched for a range of factors (including valence, arousal, imageability, frequency of use, number of letters and syllables) were presented to 59 right-handed participants in a passive reading task. Whereas all the words activated the left inferior frontal (BA44/45) and the posterior middle and superior temporal gyri (BA21/22), taste-related words produced a significantly stronger activation in these same areas, and also in the anterior insula, frontal operculum, lateral orbitofrontal gyrus and thalamus among others. As these areas comprise primary and secondary gustatory cortices, we conclude that the meaning of taste words is grounded in distributed cortical circuits reaching into areas that process taste sensations