Exploring the Everyday Inner Experience of Grapheme-Color Synesthetes

Synesthesia is a rare, multivariant condition where the stimulation of one sensory or cognitive sense induces extraordinary inner experiences. Grapheme-color synesthesia is a kind of synesthesia where the presentation of letters and/or numbers induce automatic, directly apprehended color phenomena within synesthetes (i.e., individuals with synesthesia). Despite synesthesia’s being defined by remarkable color experiences, first-person investigations that directly study synesthetes’ inner experience are rare. We used descriptive experience sampling (DES) to describe the everyday inner experience of six grapheme-color synesthetes, each sampled for from 6 to 14 sampling days. Our idiographic findings showed that the salient features of each individual participant’s sampled experience were very different from non-synesthetes in that our synesthetes each had some anomalous characteristics and some unusually co-occurring phenomena. Anomalous experiences included instances where what had been apprehended (e.g., the experiential content) involved anomalous features (e.g., inner seeings from unusual perspectives) and instances where how phenomena had been apprehended (e.g., the experiential modality) was anomalous (e.g., visual phenomena that were apprehended as heard rather than seen). Anomalously co-occurring instances were single apprehended events that were directly apprehended across inextricably diverse simultaneous modes (e.g., directly apprehending toothache both as a felt sensation and an inner seeing). We found very few instances of conventional, straightforward grapheme-color phenomena.