Teuscher, U. and Hubbard, E.M. (2007, January). Neural constraints on synesthetic mappings and conceptual metaphors: The case of time and space. American Synesthesia Association, St. Petersburg, Florida.

Previous synesthesia research has argued that synesthesia may provide an important basis for higher-level conceptual processes such as metaphor. In the current talk we examine one well-studied class of conceptual metaphor, the Time is Space metaphor, in light of recent studies of synesthesia. The cross-cultural existence of this metaphor has traditionally been interpreted as a result of our common embodied experiences in the world. Although we agree that experience is important, we suggest that this metaphorical mapping may arise not solely because of the structure of our embodied experience, but also because of the structure of our brains and the manner in which our brains make sense of that experience. From that perspective, we note here the close correspondence between the Time is Space metaphor and time-space synesthesia, in which temporal sequences are represented as having spatial locations. Recent findings in human neuroimaging, neuropsychology and monkey physiology suggest that the parietal cortex houses circuitry crucial for both temporal and spatial representations. We suggest that the same neural structures that are involved in the representation of sequences and space, which in synesthetes may lead to perceptual experiences, are connected to a lesser degree in everyone, thus providing a brain based constraint on the universal Time is Space metaphor. A better understanding of the bottom-up constraints imposed on our conceptual structures by our neural structures has profound implications for our understanding of metaphor and cognition.