Lexical-gustatory Synesthesia and Food- and Diet-related Behavior

Abstract

Lexical-gustatory synesthesia is a subvariant of the inherited neurological condition known as synesthesia, which is characterized by a merging of sensory and/or cognitive functions. Synesthetes experience two (or more) sensations when only one modality is stimulated. For example, synesthetes might hear sounds but also see colors when listening to music. Alternatively, synesthetes might see colors when touching surface textures, or when experiencing the taste of food in the mouth. Synesthesia has a known genetic basis and is linked to increased structural connectivity in the brain. This hyperconnectivity arises from neuro-developmental differences in the brain maturation of synesthetes, but can be influenced by environmental factors such as learning and experience. In lexical-gustatory synesthesia, reading, saying, or hearing words triggers accompanying food sensations, and these are experienced as either veridical perceptions of flavor (e.g., the word jail tastes of bacon in the mouth) or as an overwhelming and automatic cognitive association between the triggering word and the food type (e.g., the word jail evokes the notion of bacon). These sensations are related to diet and eating behaviors, and have a profound impact on the life of the synesthete. This chapter describes the characteristics of this unusual condition.