Synesthesia and Consciousness

While interest in synesthesia among cognitive scientists has been steadily increasing in recent years, one question remains relatively unexplored: what is the relationship between synesthesia and consciousness? In this chapter, we consider some central aspects of this relationship and focus our discussion on two main questions. First, we explore the question of whether synesthesia can occur unconsciously. We identify some complications that arise in interpreting some of the relevant empirical results, and then endorse an affirmative answer to this question based on the limited findings available. Second, we look at four major theories of consciousness and evaluate their predictions regarding the neural correlates of consciousness using synesthesia as a test case. We highlight the ways in which findings concerning the neural correlates of synesthetic experience would seem to offer support for or against these major theories.