How does sensory experience affect the way people use and understand synaesthetic metaphor?

Synaesthesia is a rare neurological condition where one sense involuntarily stimulates another, e.g. seeing colours when hearing sounds. However, synaesthetic metaphors, which describe experience in one sensory modality through another, are commonly used in cross-modal expressions like sharp cheese, loud shirt, and sweet melody. Existing research on synaesthetic metaphor (Ullman, 1945; Williams, 1976; Evans and Wilkins, 2000; Littlemore, 2019; Winter, 2019) mainly focuses on language in sighted, hearing, neurotypical people. However, as sensory language is one of the most direct ways in which people share their experiences, it is important to conduct research using non-normative participants. This project will investigate how the sensory experience of blind, deaf, or synaesthetic individuals affects the way they understand and use sensory language. It will tackle one of the most important hypotheses within the emerging field of sensory linguistics: are differences in a person's sensory experience reflected in differences in language use? How does a person's felt, physical experience influence the way they communicate?

Although previous research has studied blind individuals' understanding of sensory language (Bedny et al., 2019; Lenci et al., 2013; Vidali, 2010), and deaf individuals' use of metaphor (Kaneko and Sutton-Spence, 2016; Siqueira and Gibbs, 2016; Wilcox, 2000), my focus will be on synaesthetic metaphor. I will also build on existing research into cross-modal associations in synaesthetes (Cuskley et al., 2019; Moos et al., 2014), particularly Littlemore's (2019) work, which found that synaesthetes were more likely to use cross-sensory language, reporting enhanced empathy, stronger connections between the senses, and more physical responses to metaphorical language. I will extend this work by using the modality rating paradigm established by Lynott and Connell (2009, 2013). These studies collected a large set of "modality norms" by asking participants to rate how much they perceive a word through each of the five common senses, resulting in a perceptual rating strength for each sense (Lynott and Connell, 2009, 2013; Winter, 2016). For instance, the word yellow is very unisensory, receiving high ratings for sight only, while harsh is more multisensory, receiving high ratings for all senses. In this project I will apply this method to those with different sensory experiences and compare the results.

In the first part of the project I will collect modality norms across the participants. This will be supported by questionnaires regarding the literalness of synaesthetic metaphor. The third part of the project will be a corpus-based comparison of sensory language used by sighted and hearing neurotypical people, blind individuals, deaf individuals, and synaesthetes respectively.

The key research questions are:

- Do synaesthetes use and understand cross-modal language differently to non-synaesthetes? Because they experience one sense through another, do they have a more literal understanding of synaesthetic metaphor?

- Do congenitally blind or deaf people use and understand cross-modal language differently to sighted or hearing people? Does their sensory impairment require them to comprehend some sensory adjectives through other senses?