Synesthesia Vs. Crossmodal Illusions
We can discern two opposing viewpoints regarding synesthesia. According to the first, it is an oddity, an outlier, or a disordered condition. According to the second, synesthesia is pervasive, driving creativity, metaphor, or language itself. I favor the first perspective, according to which cross-sensory synesthesia is an outlying condition. But the second perspective is not wholly misguided. My discussion has three lessons. First, synesthesia is just one of a variety of effects in which one sense causally impacts and reshapes experience associated with another. These effects are utterly common. However, due to their unfamiliarity and their conflict with a widespread conception of the role of the senses in perception and experience, until recently they have been surprising. Second, synesthesia nevertheless must be distinguished from other intermodal effects that lead to misperception, such as crossmodal illusions. Third, synesthesia may also be distinguished from the potentially much broader class of synesthetic effects.