Timbre Impacts the Consistency of Music-Color Synesthesia
Radhika S. Gosavi1, Rory Bade1, Edward M. Hubbard1; 1University of Wisconsin-Madison
Several popular musicians have noted that “seeing” music enhances their compositions. These musicians experience synesthesia, a condition in which stimulation of one sensory modality evokes experiences in a second, unstimulated modality (Simner & Hubbard, 2013). While music-color associations have been observed in nonsynesthetes (Palmer et al., 2013), synesthetes make these associations with significantly higher consistency (Ward, 2006). Here, we tested whether group differences in consistency were driven by musical properties. We investigated music-color associations in nine synesthetes and nine nonsynesthetes by instructing participants to pick the color that best matched a sound. We presented musical stimuli that systematically varied by pitch, composition (chords, notes) and timbre (tuba, piano, saxophone, violin). Consistency was calculated as the difference between the colors chosen for the first and second stimulus presentations on the dimensions of hue/color, saturation/intensity and value/lightness. We found that synesthetes were significantly more consistent for all color dimensions, but that group differences were greatest in the hue dimension for saxophone (p=0.004) and violin (p=0.02), and in the value dimension for tuba (p=0.02) and piano (p=0.02). These findings show that synesthetic music-color associations are modulated by timbre, suggesting that later auditory regions, beyond primary auditory cortex, may form the neural basis of music-color synesthesia. Previous studies have noted timbre processing occurs in the superior temporal sulcus (STS), which is also involved in audiovisual integration (Beauchamp et al., 2004; Menon et al., 2002). Future studies should test whether cross-activation involving the STS is the neural basis of music-color synesthesia (Hubbard et al., 2011).
Topic Area: PERCEPTION & ACTION: Multisensory