The Relationship Between Music-Related Types of Synesthesia and Mental Imagery in Synesthete Musicians

Synesthesia is a perceptual and conceptual phenomenon that has been linked to a heightened capacity for mental imagery. However, our understanding of music-related types of synesthesia and mental imagery is still in its infancy. This study therefore aims to examine the relationship between music-related types of synesthesia and mental imagery in a sample of synesthete musicians. Four forms of data collection were employed: an online survey, a synesthesia test battery, an absolute pitch test, and a semi-structured interview. This article focuses on results obtained in response to open-ended questions relating to synesthete musicians’ mental imagery. An analysis of the interview data revealed heightened vividness of auditory imagery (AI), including the ability to control the speed, dynamics, and intensity of the imagery. A bidirectional analysis of the functional relationship between AI and synesthesia ascertained that multimodal mental imagery (MMI) could be triggered by AI, thus bypassing the need for sensory stimulation. Furthermore, cases of complex visual imagery (CVI) were confirmed to meet the synesthetic criteria of being automatic and involuntary, as well as being consistent and stable mappings between specific musical stimuli and CVI. These findings are noteworthy as they call into question the general assumption that synesthetic percepts are generic and simple in nature. Together, these findings contribute to our understanding of music-related types of synesthesia and mental imagery, challenge contemporary understanding of certain categorical aspects of music-related synesthetic percepts, and provide us with a deeper understanding of the nature of cross-modal associations in general.