Abstract
Previous research has shown that normal volunteers have an unexpectedly high level of consistency in their associations between individual colors and different musical sounds including intervals and instrumental timbres. These cross-modal associations seem to be mediated by emotional meaning, such that colors are consistently paired with sounds that have the same emotional valence (Griscom & Palmer, VSS 2013). In the present research, we extend this paradigm to look at the more unusual sound-to-color mappings that occur in individuals with audiovisual synesthesia. We recruited 15 volunteers who reported timbre-color synesthesia and verified their synesthesia using the Eagleman Synesthesia Battery (Eagleman, 2006). They then completed a series of tasks in which they reported their associated color experiences for a wide array of musical intervals and timbres, as well as for longer pieces of music, using a method similar to that used previously to measure associations in non-synesthetes. We found that these synesthetes have interval-color and timbre-color mappings which, although highly variable across individuals, on average show a structure similar to that of color associations reported by non-synesthetes in earlier studies. Both the synesthetic participants and a non-synesthetic control group showed strong effects of emotional mediation in their color pairings. In addition, we found that color-emotion synesthesia was most common type of synesthesia to co-occur with color-music synesthesia in our volunteers. Together, these findings suggest that audio-visual synesthesia is likely the result of a complex network of processes involving emotion and semantics, rather than simply being the result of an overabundance of low-level connections in auditory and visual brain regions.
Meeting abstract presented at VSS 2014