Exploring conceptual representation and grounding through perceptual strength norms in deaf individuals

In this study, our objective was to explore the impact of hearing loss on the conceptual system underlying word meaning. We collected perceptual strength norms for 200 Italian words from early deaf individuals with limited or no access to auditory information and compared them to existing norms from hearing individuals. For each word, participants provided perceptual strength ratings for each perceptual modality. Our results revealed a significant reduction of the auditory modality in the norms provided by deaf individuals compared to the hearing population. However, we did not observe an overall decrease in reported perceptual strength. Interestingly, we found a heightened involvement of other sensory modalities accompanied by reduced modality exclusivity in the conceptualization of words, indicating that deaf individuals heavily rely on information coming from the other perceptual modalities to form concepts. These findings suggest that hearing loss leads to a reorganisation of word conceptualization, characterised by increased multisensoriality. Importantly, although diminished, the auditory modality remains present, suggesting that deaf individuals can still infer auditory-associated knowledge about words to some extent.