A Scarlet Letter: Color Perception in Synesthesia By Kathryn Maryann Frorer

Abstract

Synesthesia is a neural phenomenon that results in cross-modal experiences of sensory information. Previous research has supported the hypothesis that synesthesia is a neurological condition based on perceptual stimuli rather than memory. The following research strives to determine how color information is coded in both grapheme-color and auditory-visual synesthesia. Five behavioral programs and an EEG study using the Emotiv EPOC+ tested the hypothesis that color perception is based on low-order perceptual information coded by the inducing stimuli, such as the shape of a grapheme or the qualities of a sound. It was hypothesized that the research conducted by Brang et al. (2011), which builds upon the Cascading Cross- Tuning Model of Ramachandran & Hubbard (2001), would be supported by further grapheme-color research, and that these paradigms could also be applied to auditory-visual synesthesia. Further, it was hypothesized that the synesthesia-dependent response modulation found by Beeli et al. (2007) would be reproducible with the Emotiv EPOC+. These hypotheses are supported by the results, with a few notable exceptions. It is concluded that grapheme-color and auditory-visual synesthesia are dependent on the presentation of the inducing stimuli, which suggests a role for low-order processing in both grapheme- color and auditory-visual color perception.